Lymphatic system: a prospective area for advanced targeting of particulate drug carriers

1. Introduction

2. Targets for lymphatic delivery

3. Carriers for lymphatic

targeting

4. Physicochemical properties of

carriers for lymphatic targeting

5. Conclusion

6. Expert opinion

Review

Lymphatic system: a prospectivearea for advanced targeting ofparticulate drug carriersIndu Singh, Rajan Swami, Wahid Khan & Ramakrishna Sistla†

†National Institute of Pharmaceutical Education & Research (NIPER),

Department of Pharmaceutics, Hyderabad, India

Introduction: The lymphatic system has a critical role in the immune system’s

recognition and response to disease and it is an additional circulatory system

throughout the entire body. Extensive multidisciplinary investigations have

been carried out in the area of lymphatic delivery, and lymphatic targeting

has attracted a lot of attention for providing preferential chemotherapy

and improving bioavailability of drugs that undergo hepatic first-pass

metabolism.

Areas covered: This review focuses on progress in the field of lymphatic

therapeutics and diagnosis. Moreover, the anatomy and physiology of the

lymphatic system, particulate drug carriers and different physicochemical

parameters of both modified and unmodified particulate drug carriers and

their effect on lymphatic targeting are addressed.

Expert opinion: Particulate drug carriers have encouraged lymphatic target-

ing, but there are still challenges in targeting drugs and bioactives to specific

sites, maintaining desired action and crossing all the physiological barriers.

Lymphatic therapy using drug-encapsulated lipid carriers, especially lipo-

somes and solid lipid nanoparticles, emerges as a new technology to provide

better penetration into the lymphatics where residual disease exists. Size is

the most important criteria when designing nanocarriers for targeting lym-

phatic vessels as the transportation of these particles into lymphatic vessels

is size dependent. By increasing our understanding of lymphatic transport

and uptake, and the role of lymphatics in various diseases, we can design

new therapeutics for effective disease control.

Keywords: liposome, lymph nodes, lymphatic targeting, nanocarriers, nanoparticles

Expert Opin. Drug Deliv. (2014) 11(2):211-229

1. Introduction

Lymph is the fluid that circulates throughout the lymphatic system. It serves as the‘middle man’ between the blood and tissues. The cardiovascular system forms aclosed circle around which blood is pumped by the heart, whereas the lymphaticsystem comprises a one-way, open-ended network without a central driving force [1].The lymphatic system was first recognized by Gasparo Aselli in 1627 and its anat-omy was almost completely characterized by the early nineteenth century [2]. Twodifferent theories have been proposed, which are in favor of the origin of the lym-phatic vessels. First, the centrifugal theory of embryologic origin of the lymphaticsdescribed in the early twentieth century by Sabin and later by Lewis, postulatingthat lymphatic endothelial cells (LECs) are derived from the venous endothelium [3].Later, the centripetal theory of lymphatic development was proposed by Hunting-ton and McClure in 1910, which describes the development of the lymphaticsystem beginning with lymphangioblasts, mesenchymal progenitor cells, arisingindependently of veins, followed by venous connection [4]. Maintenance of normal

10.1517/17425247.2014.866088 © 2014 Informa UK, Ltd. ISSN 1742-5247, e-ISSN 1744-7593 211All rights reserved: reproduction in whole or in part not permitted

Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.

http://informahealthcare.com/journal/EDD

tissue fluid balance, absorption of lipids and fat-soluble vita-mins from the intestine and transport of immune cells arethe basic key functions of the lymphatic system. Lymphaticsalso transport the antigen-presenting cells and antigens fromthe interstitium of peripheral tissues to the draining lymphnodes where they start immune responses via B and T cellsin the lymph nodes [5]. The lymphatic system offers themechanism of re-entry of large molecules into the bloodcirculation.

1.1 Anatomy and physiology of the lymphatic

systemThe lymphatic system is a part of the circulatory systemconsisting of lymphatic vessels, lymph nodes, spleen, thymus,Peyer’s patches and tonsils, which play important roles inimmune surveillance and response [6]. It is a single, irrevers-ible, one-way transit network without a principal drivingforce [5]. The lymphatic vasculature under normal physiolog-ical conditions transports cells and fluid from the tissue inter-stitium back to the systemic circulation [7], and it starts in thedermis with initial lymphatic vessels [5]. Lymphatic capillariesconsist of a single layer of thin-walled, non-fenestrated LECswith few intercellular junctions present over each other akinto blood capillaries. These extremely porous capillaries workas a gateway for large particles, cells and interstitial fluid. Par-ticles larger than 100 nm in diameter that can extravasate intothe interstitial space get phagocytosed by macrophages and arefinally passed to the lymph nodes [1,8]. Elastic anchoring fila-ments connect lymphatic capillary endothelial cells to theextracellular matrix controlling vessel collapse under high

interstitial pressure [1,9]. The initial lymphatic vesselsoverlying endothelial cell--cell contacts prevent fluid refluxback into the interstitial space [10]. Lymph is received fromthe initial capillary lymphatic by deeper collecting vessels.These collecting vessels in combination with the contractionof surrounding skeletal muscles and arterial pulsations pushthe lymph into the lymph nodes [11]. The collecting lymphaticvessels join into lymphatic trunks and the lymph is ultimatelyreturned to the venous circulation into the left subclavian veinvia the thoracic duct [12]. The increase in interstitial pressureas well as contractions of the lymphatic vessels supports thelymph flow toward the circulatory system [13].

1.2 Potential of lymphatic targetingThe lymphatic system acts as the site for many diseases likemetastitial tuberculosis (TB), cancer, filariasis and so on [14].It plays an active role in cancer metastasis. Conventionalsystemic chemotherapy is not proven effective for deliv-ering drugs to the lymphatic system without dose limitingtoxicities [15].

Following presentation to lymph nodes, the lymphaticsystem takes part in the clearance of particulate matter fromthe interstitium and this has created interest in designingmicroparticulate systems to target regional lymph nodes.A molecule’s composition is important in determining uptakeinto the lymphatics and retention within the lymph nodes.Particulate materials, for example, liposomes, activated carbonparticles, emulsions, lipids and polymeric particulates, arehighly taken up by the lymphatics and are emerging aspotential carriers for lymphatic drug targeting [16].

Additionally, lymphocytes are central to the progression ofautoimmune disease, transplant rejection, leukemia, lym-phoma and lymphocyte-resident viral diseases such as HIV/AIDS. Strategies to target drug treatments to lymphocytes,therefore, represent an opportunity to enhance therapeuticoutcomes in disease states where many current treatmentregimes are incompletely effective and promote significanttoxicities [4]. Evaluating the significance of the lymphatics inliaison to many diseases, the number of studies scrutinizingdrug delivery or targeting of various therapeutics to the lym-phatics has been fairly modest. Developments of a growingnumber of diverse types of delivery systems to aid the lym-phatic transport of drugs offer many new approaches tolymphatic drug delivery and transport.

2. Targets for lymphatic delivery

The lymph is believed to be a successful therapeutic target formany diseases and a number of detailed investigations of drugtargeting to the lymphatics are modest. This may reveal theearlier idea that the lymphatics play a minor role in drugabsorption; however, results imply that under certain circum-stances, the lymphatics may provide the main route of drugabsorption and lead to a significant drug concentration inthe lymph, some 5000 -- 10,000 times higher than in systemic

Article highlights.

. The lymphatics have the potential to play a major role inanticancer treatment as lymphatic spread is recognizedto precede hematological spread in many cancersincluding melanoma, breast, colon, lung andprostate cancers.

. Various physicochemical properties especially size arethe most important design criteria for nanocarriers fortargeting lymphatic vessels as the transport ofparticulates into lymphatic vessels is dependent onparticle size.

. Lymphatic targeting has attracted lot of attention forproviding a preferential anticancer chemotherapy andimproving bioavailability of drugs that undergoes hepaticfirst pass metabolism.

. Targeting drugs to the lymphatic system dependscompletely on the intricate physiology of the lymphaticsystem and physicochemical properties of the carriers.

. Nanocarriers, especially the surface modified carriers,can meet the needs for effective targetingto lymphatics.

. Lipidic carriers provide better penetration into thelymphatics where residual disease exists.

This box summarizes key points contained in the article.

I. Singh et al.

212 Expert Opin. Drug Deliv. (2014) 11(2)

Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


plasma. Advances in drug design and delivery have also led tothe emergence of an increasing number of i) highly lipophilicdrug molecules, which may serve as a substrate for intestinallymphatic transport; ii) macromolecular biotechnologicalproducts, which appear to be absorbed into the peripherallymphatics after subcutaneous (s.c.) injection; and iii) a rangeof particulate colloidal systems which may aid the lymphatictransport of drugs molecule with little intrinsic lymph direct-ing capacity. There are many diseases where lymph is a part oftheir prognosis or latency period (cancer, HIV, filaria, TBetc.), show pathophysiological changes in lymphatic systemand act as a prey to lymphatic targeted approach. Similarly,lymphatic expansion has been found in various chronicinflammatory disorders, including psoriasis, atopic dermatitis,inflammatory bowel disease and rheumatoid arthritis [17].Furthermore, lymphangiogenesis appears to be associatedwith acute rejection of organ transplants, for example, of thelung and kidneys [18,19].

2.1 CancerThe lymphatic system has an active role in cancer metastasis.Lymph node dissemination is the major cause of the spread ofsolid tumors [20]. Skobe et al. established the biological signifi-cance of intratumoral lymphangiogenesis in breast cancer andidentified VEGF-C as a molecular link between tumor lym-phangiogenesis and metastasis [21]. Similarly, Yonemura et al.suggested that cancer cells producing VEGF-C may induce theproliferation and dilation of lymphatic vessels, resulting in thedevelopment of invasion of cancer cells into the lymphatic vesseland lymph node metastasis [22]. Lymphangiogenic growth fac-tors, the enzymes that activate them and the cell surfacereceptors signaling for growth of lymphatic vessels are prime tar-gets for anti-lymphangiogenic drugs designed to restrict cancermetastasis [23].

With regard to the diagnosis of cancer metastasis the statusof the lymph node is a major determinant of the patient’sdiagnosis. This includes metastatic detection of removedlymph node either by histologic analysis or by MRI usingcontrast agents. The most important factor that determinesthe appropriate care of the patient is correct lymph nodestaging [24]. In different studies, authors have also stated that2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positronemission tomography (PET) enables accurate staging ofregional lymph node disease in patients with non-small celllung cancer and cervical cancer [25,26]. But patient survivalshave been shown to improve by the therapeutic interventionsthat treat metastatic cancer in lymph nodes with either surgeryor local radiation therapy [27,28]. The concept of sentinellymph node mapping assumes an orderly progression of met-astatic disease from the primary tumor to the lymphatic sys-tem. It postulates that tumors drain directly to a limitednumber of lymph nodes in a specific lymphatic drainagebasin. Much breakthrough technology includes introducingnew delivery nanoparticles (NPs) for identification of primarydraining or sentinel lymph node or developing combination

of using gadolinium-based MRI contrast agents, to enhancethe sentinel lymph node imaging diagnosis [29,30].Dunne et al. presented an interstitial translymphatic therapeu-tic approach using cis-diaminedichloro-platinum(II) (CDDP)conjugated to a poly(ethylene oxide)-block-poly(lysine) blockcopolymer tracking systems for the successful treatment oflymph node metastasis. Most effective was the application ofa high cargo-load CDDP tracking system (48 wt. %CDDP) curing 90% of the animals and with minor localside-effects. Systems containing 1 or 10 wt. % of CDDPwere less effective but still cured 50% of the animals. More-over, the administration of 1 or 10 wt. % of CDDP consis-tently limited tumor growth to the draining lymph nodes(50%) and prevented systemic distribution of the metastasiseven with 1 wt. % CDDP load. The systems contained0.25 -- 0.003 mg/kg body weight CDDP compared to 1 ml/kgbody weight as usually used for intravenous (i.v.) administra-tion [31]. Kaminskas et al. studied the efficacy of protein-basedtherapeutics in the treatment of lymphatic diseases by enhanc-ing lymphatic disposition. This group examined if PEGyla-tion can be applied to improve the lymphatic uptake ofinterferon a2 and whether this ultimately translates intoimproved therapeutic efficacy against lymph-resident cancer.The lymphatic pharmacokinetics of interferon a2b (IFN,19 kDa) and PEGylated interferon a2b (IFN-PEG12,31 kDa) or a2a (IFN-PEG40, 60 kDa) were examined inthoracic lymph duct cannulated rats. IFN was poorlyabsorbed from the s.c. injection site (Fabs 36%) and showedlittle uptake into lymph after s.c. or i.v. administration(£ 1%). In contrast, IFN-PEG12 was efficiently absorbedfrom the s.c. injection site (Fabs 82%) and ~ 20 and 8% ofthe injected dose was recovered from thoracic lymph over30 h after s.c. or i.v. administration, respectively [32].

2.2 HIVPrimary HIV is characterized by an early viremia followed bya specific HIV immune response and a dramatic decline ofvirus in the plasma [33]. Long after the HIV virus is found inthe blood, it can be found in high levels in mononuclear cellslocated in lymph nodes. Viral replication in these lymphnodes has been reported to be about 10- to 100-fold higherthan in the peripheral blood mononuclear cells [34]. Faciallymphoedema has also been reported in many HIV positiveKaposi sarcoma patients. Lymphoedema is associated withagenesis, hypoplasia or ectasia of lymphatic channels anddamage to or obstruction of normal lymphatic channels inter-fering with lymphatic flow along with local immuneimpairment. Migration of immunoregulatory cells such asdendritic cells, T lymphocytes and macrophages from periph-eral tissue sites to regional lymph nodes via lymphatic vesselsis compromised in the setting of lymphoedema. This resultsin ineffective clearance of antigens and impaired localadaptive cellular immune responses as well as immune surveil-lance [35]. Apart from facial lymphoedema, follicular dendriticcells have also been proposed as a viral reservoir. These cells

Lymphatic system

Expert Opin. Drug Deliv. (2014) 11(2) 213

Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


are present in the follicles formed in all secondary lymphoidtissue [36]. Standard oral or i.v. drug delivery to these lymphnode mononuclear cells is difficult [37]. Even if highly activeanti-retroviral therapy (HAART) can reduce plasma viralloads in HIV infected patients by 90%, active virus can stillbe isolated from lymph nodes even after 30 months ofHAART therapy. Current anti-HIV/AIDS treatment regi-mens may provide a dramatically improved quality of lifefor HIV-positive people. The most interesting possibility innanocarrier based delivery of anti-HIV/AIDS drugs is multi-functionalization of the nanocarrier system. With multi-func-tionalization, incorporation of several therapeutic agents (e.g.,HAART) in one formulation is possible which may exert bet-ter clinical effect than non-functionalized formulation. How-ever, Horiike et al. suggested that lymphatic tissues, includingmesenteric lymph nodes, contain major cellular reservoirs thatcause rebound of plasma viremia upon cessation of HAARTtherapy. They corroborated their conclusions with evidencesof detection of higher titers of viral RNA in the lymphoidtissues of virus-infected animals undergoing antiretroviraltherapy. Therefore, to achieve a complete cure of HIV-1infection, it is essential to eradicate these viral reservoirs [38].There are some very recent therapies for HIV/AIDS like pep-tides, small interfering RNA and oligonucleotides based deliv-eries. The development of Tat peptide based nanoparticulatedelivery systems has proven well recently in this direction [39]

and we can expect some good results in the future for elimi-nating HIV/AIDS. But none of them specifically targetlymphatic system, where true viral titer persists.

2.3 FilariaLymph nodes are the key element in the life cycle of severalparasite organisms, including filaria. It has been suggestedthat lymphatic dilatation could be attributed to parasiticinfection and its related products, whereas severe lymphaticobstruction may be a consequence of immunologically medi-ated inflammation during a chronic infective state [40]. Lym-phatic vessels and lymph nodes of infected patients can carryadult worms. This adult filaria obstructs the lymphatic drain-age that results in swelling of extremities distal to the infectedlymph node. These very symptoms of swollen limbs inpatients with filarial disease have been termed elephantiasisor filariasis. Visualization of the adult worms by ultrasoundimaging demonstrates that the worms reside in nests locatedin the lymph nodes and lymphatic vessels. It is very difficultto destroy the adult worms present in the lymphatic system,although microfilarias from adult worms that are releasedinto the blood stream are very reactive to anti-filarial medica-tions. This treatment may be difficult due to poor drug pen-etration in the nests of lymphatic system where the adultworms are localized [41]. Novel drug delivery has the potentialfor treating filarial disease, particularly before the lymphaticshave become totally obstructed. Surface modifications ofpolymeric NPs are quite essential to enhance localization ofantifilarials close to lymph-resident filaroids [42].

2.4 AnthraxIn anthrax infection, endospores from Bacillus anthracis, grampositive rod shaped bacteria, that gain access into the body,are phagocytosed by macrophages. Macrophages are thentransported to the lymph nodes where germination of thespores occurs and they transform into vegetative bacteria [43].Only during its transformation from an activated spore to anascent vegetative cell is it an intracellular passenger. Thisprocess occurs at some point during or prior to its transloca-tion from the pulmonary epithelium via the alveolar macro-phages to the pulmonary lymphatics and the germinationmay extend to almost 60 days. According to one literaturecomputed tomography of the chest was performed on eightpatients infected with inhalational anthrax. Mediastinallymphadenopathy was found in seven of the eight patients [44].Treatment and control of these diseases are hard to accom-plish because of the limited access of drugs to mediastinalnodes using common pathways of drug delivery. Also, theanatomical location of mediastinal nodes represents a difficulttarget for external beam irradiation.

2.5 TuberculosisThe TB infection is caused by various strains of mycobacteria,usually Mycobacterium tuberculosis, that invade and growchiefly in phagocytic cells. Lymph node TB is the most com-mon form of extrapulmonary TB rating ~ 38.3% of all formsof TB. This is frequently found to spread from the lungs tolymph nodes. In one study, total TB lymph node involvementwas found as 71% of the intrathoracic lymph nodes while26% of the cervical lymph nodes and 3% of the axillarylymph nodes [45]. Basaraba et al. corroborated the evidencesof progression of TB from lymphatic infection in guineapig. Pulmonary lymphatics provide a direct route for thespread of M. tuberculosis from the initial site of infection inthe lung to the draining lymph nodes, where the acquiredimmune response is initiated, preventing the further influxof effecter or memory immune cells or the chemotherapeuticagents from reaching inhibitory concentrations [46]. A similarcondition is also seen in humans known as Ghon primarycomplex, where both lung and lymph node lesions can prog-ress rapidly, with the lymph nodes representing the first ofmultiple sites of extrapulmonary spread [47,48]. This studyalso suggests that the lymphatic vessels themselves developprogressive inflammation as part of the primary infection.Newer methods to target antituberculosis drugs to theselymph nodes could possibly decrease the amount of time ofdrug therapy and improve the quality of life.

2.6 LeishmaniasisLeishmaniasis is caused by obligate intracellular protozoanparasites of genus leishmania. The leishmania parasites livein the macrophages as round, non-motile amastigotes thatchange into motile form ‘promastigote’ after getting releasedin blood. Although sera from infected individuals and certain

I. Singh et al.


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


mammals contain factors capable of agglutinating or lysingpromastigotes in vitro, within the host macrophages, theamastigotes are protected from antibodies and other circulat-ing substances that might be harmful to the parasite. Amasti-gote maturation occurs in these macrophages. Targeting thematuration site ‘macrophages’ can help to stop progressionof disease. Lymphatic targeting is always considered helpfulbecause of the higher concentration of macrophages in lym-phatics. Research is going on for past 30 years on variousnovel delivery systems for delivery of antileishmanial drugs.But, AmBisome� (Gilead Sciences, Inc., San Dimas, CA) isthe only drug delivery system available in the market forvisceral leishmaniasis (VL) [49], although stability problemand extremely high cost makes it a tough choice for treatmentof VL. Other systems exploited include the polymeric partic-ulate system, especially micro and NPs for passively andactively targeting experimental VL using a series of antileish-manial drugs and polymers [50-52].

3. Carriers for lymphatic targeting

Nanocarriers have encouraged lymphatic targeting; but stillthere are challenges of locating drugs and bioactives to specificsites, maintaining desired action and crossing all the physio-logical barriers. These hurdles could be overcome by the use

of modified nanosystems achieved by the surface engineeringphenomena. Figure 1 illustrates various lymphatic organs,their functions and therapeutic carriers assisted lymphdelivery with special reference to HIV and cancer, whenadministered through oral or s.c. route.

3.1 Lipidic carriersLipid based drug delivery systems can be explored as potentialvehicles for site specific drug delivery to lymphatics. Manyparticulate systems such as emulsions, lipid solutions, microe-mulsions, micellar solutions, liposomes and lipid NPs areinvestigated for targeting of drugs to the lymphatic system.The major purpose of lymphatic targeting is to providean effective chemotherapy in preventing the disease byaccumulating the drug in the regional lymph node.

3.1.1 Emulsifying drug delivery systemsEmulsifying drug delivery systems (EDDSs) offer a varietyof options like emulsions, self-emulsifying drug deliverysystems (SEDDSs), self-microemulsifying drug delivery sys-tems (SMEDDSs) and self-nano-emulsifying drug deliverysystems (SNEDDSs). Emulsions have been widely usedfor lymphatic targeting. Hashida et al. demonstrated thatinjection of water in oil (w/o) or oil in water (o/w) emul-sions favored lymphatic transport of mitomycin C via the

Fenestration inlymph node

cancer

Peyer's patches coveredby M cells in intestineaids in lymph targetingfrom oral route

• Anti HIV therapy• Anti cancer therapy• Bypass first pass metabolism

Lym

ph v

esic

le

Lymph nodeThoracic duct

Thymus: serves as the site ofT-lymphocyte maturation,development, and control

Lymph node: monitors thecomposition of lymph, thelocation of pathogenengulfment and eradication,the immunologic response, andregulation

Spleen: monitors thecomposition of bloodcomponents, the location ofpathogen engulfment anderadication, the immunologicresponse, and the regulationsite

Peyer’s patches: immunesurveillance of the intestinallumen and in facilitating thegeneration of the immuneresponse within the mucosa

s.c. administration

A

B

C

D

E

Lymphatic organs Delivery methodology Reduced lymphaticdrainage

Figure 1. Drug loaded carrier administration for lymph targeting. A. Uptake of carriers from intestine to lymph through

peyer’s patches after oral administration; B. particle movement through lymph vesicles; C. uptake of carriers in lymph node

associated with tumor through enhanced permeability and retention effect (in case of cancer) or active targeting depending

upon surface properties of carriers and increased retention of particles due to decreased lymphatic drainage; D. for systemic

effect as in non-HIV diseases (where microbs titer is in blood), carriers enter into systemic circulation through thoracic duct;

E. subcutaneous administration also leads to direct absorption of carrier in lymph nodes through lymph vessels.

Lymphatic system


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


intraperitoneal (i.p.) and intramuscular (i.m.) routes [53].Selective uptake after injection into the regional lymphaticswas reported in the order of o/w > w/o > aqueous solution.In another work, gelatin spheres in oil emulsion were devel-oped to increase the stability of the w/o emulsion. Thenanoparticle-in-oil emulsion system containing antifilarialdrug in gelatin NPs enhanced lymphatic targeting andthis colloidal system had an outstanding possibility to per-form as a lymphotropic carrier system. Pirarubicin and lip-iodol emulsion formulation were developed for treatinggastric cancer and metastatic lymph nodes [54]. Afterendoscopic injection of the pirarubicin-lipiodol emulsion,the drug retained over 7 days at the injection site and inthe regional lymph node.Wang et al. designed three formulations including methy-

lene blue solution, methylene blue w/o microemulsion andmethylene blue multiple microemulsion to target methyleneblue to regional lymph nodes and found that methyleneblue microemulsion can target methylene blue to regionallymph nodes and can be employed as a potential lymph tracerin sentinel lymph node biopsy [55]. Hauss et al. has exploredthe lymphotropic potential of emulsions and SEDDS andinvestigated the effects of a range of lipid based formulationson the bioavailability and lymphatic transport of ontazolastfollowing oral administration. All the lipid formulationsincreased the bioavailability of ontazolast compared to thecontrol suspension, maximum lymphatic transport foundwith the emulsion [56].

3.1.2 LiposomeThe utility of liposomes as a carrier for lymphatic delivery wasfirst investigated by Segal et al. in 1975 [57]. Lymphatic deliv-ery of drug encapsulated liposomal formulations has beeninvestigated extensively in the past decade. Liposomes arespherical vesicles composed of a lipid bi-layer membrane,resembling tiny cells with a cell membrane but with nothingin the core. Liposomes, usually but not by definition, containa core of aqueous solution and a lipid sphere [58].By manipulating formulation lipids of different fatty acid

chain lengths, liposomes can be constructed to be temperatureor pH sensitive to permit controlled release of their contents.Ling et al. evaluated oral delivery of a poor bioavailable hydro-philic drug, cefotaxime, in three different forms: liposomalformulation, aqueous free drug and a physical mixture ofthe drug and empty liposomes. They showed that the lipo-somal formulation leads to a significant enhancement of thelymphatic localization of the drug relative to the other twoformulations [59]. Latimer et al. developed liposomes of pacli-taxel and a vitamin E analogue, a-tocopheroyloxy acetic acid(a-TEA), in an aerosol formulation for treating murinemammary tumors and metastasis [60]. Lawson et al. performeda comparative study for the anti-proliferative efficacy of a9-nitro camptothecin (9-NC) encapsulated dilauroylphospha-tidylcholine liposomal delivery, a-TEA and a combinationtherapy of 9-NC and a-TEA in a metastatic murine

mammary tumor model for curing the lungs and the sur-rounding lymph node metastases. The combination treatmentgreatly hindered the tumor progression leading to a prolongedsurvival rate compared to each treatment alone [61]. Similarly,high levels of drugs could be targeted to lymph nodes contain-ing TB infection using liposomal antituberculosis drugtherapy [62].

3.1.3 Solid lipid nanoparticlesSolid lipid NPs (SLNs) are novel drug carrier system whichconsists of a solid matrix composed of a lipid being solid atboth room and body temperatures with a mean particle sizebetween 50 and 1000 nm. SLNs are considered to be themost effective lipid based colloidal carriers, introduced inearly 1990s. They are low-cost products as the excipientsand production lines are relatively cheap and the productioncosts are not much higher than those established for the pro-duction of parenteral emulsions [63]. SLNs could be a goodformulation strategy for incorporating drugs with poor oralbioavailability due to low solubility in gastrointestinal tractor pre-systemic hepatic metabolism (first pass effect) permit-ting transportation into the systemic circulation through theintestinal lymphatics. Solid lipid NPs composed of triglycer-ides particularly resemble the chylomicrons and may alterthe absorption behavior of drugs including avoidance of firstpass metabolism. Various anticancer drugs, etoposide [64],methotrexate [65] and idarubicin [66], have been incorporatedinto SLNs and evaluated for their lymph localization.

Alex et al. prepared lopinavir loaded SLN for intestinallymphatic targeting and reported that SLNs increased thecumulative percentage dose of lopinavir secreted into thelymph, which was 4.91-fold higher when compared with aconventional drug solution in methyl cellulose suspension.The percentage bioavailability was significantly enhanced [67].Videira et al. designed technetium-99m-D,L-hexamethylpro-pyleneamine oxime radiolabeled SLN. The authors trackedthe biodistribution of SLNs from the lungs and found that4 h after administration of the radiolabeled SLN, these werelocated primarily within inguinal and axillary lymph nodes,suggesting lymphatic uptake and retention for SLNs thathad been absorbed from the lungs [68]. Lu et al. designedand evaluated solid lipid NPs of mitoxantrone against breastcancer on mice. The drug concentration of mitoxantroneSLNs in local lymph nodes was much higher and the drugconcentrations in other tissues were lower [69].

3.2 Polymeric carriersFor effective targeted and sustained delivery of drugs tolymph, several polymeric particles have been designed andstudied. The polymers are categorized in two types based ontheir origin as either natural polymers like dextran, alginate,chitosan, gelatin, pullulan and hyaluronan or synthetic poly-mers like poly lactide-co-glycolide (PLGA), poly L-lacticacid (PLA) and poly methyl methacrylate (PMMA) [70-75].

I. Singh et al.


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


3.2.1 NaturalDextran, a natural polysaccharide, has been used as a carrier fora range of drug molecules due to its outstanding biocompati-bility [71]. Bhatnagar et al. synthesized cyclosporine A loadeddextran acetate particles labeled with technetium-99m. Theseparticles gradually distributed cyclosporine A all through thelymph nodes following s.c. injection in rats [76]. Dextran con-jugated lymphotropic delivery system of mitomycin C hasalso been reported in order to assess the feasibility of a macro-molecular prodrug as a lymphotropic delivery system [77].

Hyaluronan or hyaluronic acid (HA) is a natural biocom-patible polymer that follows lymphatic drainage from theinterstitial spaces. Cai et al. demonstrated a novel intra-lymphatic drug delivery method synthesizing a cisplatin-HAconjugate for breast cancer treatment. Following s.c. injectioninto the upper mammary fat pad of female rats, most of thecarrier localized in the regional nodal tissue compared to thestandard cisplatin formulation [78].

Albumin is the most common plasma protein in mammals.Albumin microparticles were also explored for their potentialin macrophage targeting for leishmaniasis. Khan et al. usedspray dried paramomycin loaded albumin microparticles(PM-MS) to target macrophages, for the treatment of VL,and found significantly improved efficacy of PM-MS overparamomycin solution at equivalent concentration [79-82].

3.2.2 SyntheticPLGA as synthetic polymer used to prepare biodegradablenanospheres has been accounted to deliver drugs and diagnosticagents to the lymphatic system. Similarly, nanospheres coatedwith block co-polymers of poloxamers and poloxamines withradiolabeled 111In-oxine to trace the NPs in vivo have beenreported. Upon s.c. injection uptake of the block copolymer(poloxamers and poloxamines) coated nanospheres in the lym-phatic system was higher as compared to the uncoated one.Moreover, the regional lymph node showed a maximum uptakeof 17% of the administered dose [83]. Dunne et al. synthesized aconjugate of block copolymer cis-diamminedichloro-platinum(II) and poly (ethylene oxide)-block-poly (lysine) for treatinglymph node metastasis [31]. Kumanohoso et al. designed anew drug delivery system for bleomycin by loading it into asmall cylinder of biodegradable polylactic acid to target lesions.Following s.c. implantation, this system showed higher concen-tration of bleomycin in abdominal lymph nodes and higherantitumor effect [84].

Various nano andmicroparticles of charcoal, polystyrene andPLGA were studied for the lymphatic distribution followingintrapleural (i.p.l.) implantation in rats and after 3 h of i.p.l.injection the lymphatic uptake was observed [85]. Maincentet al. studied the lymphatic targeting of radiolabeled poly(a-hydroxycarboxylic acid) (PHCA) and PMMA NPs after i.p.administration in rats with a thoracic duct cannula [86]. Severalstudies have reported lymphatic delivery of paclitaxel usingnano-/microspheres. Liggins et al. investigated paclitaxel loadedPLA microspheres for prevention or i.p. carcinomatosis [87].

3.3 Miscellaneous carriers3.3.1 DendrimersIn the last two decades, dendrimers have gained popularity inthe field of drug and gene delivery due to their nanometricand homogenous size and molecular weight range. The finalarchitecture of dendrimers is usually globular, with change-able surface functional groups for medical or biologicalapplication and these surface groups are mainly responsiblefor interaction with their environment. This makes the actionof these dendritic units more versatile, allowing for drugs tobe encapsulated or attached to the surface or peripheralgroups that modulate the solubility and toxicity [88]. Den-drimers are repetitively branched macromolecules whichcould be an effective system for lymphatic imaging and target-ing. Kobayashi et al. utilized dendrimer based contrast agentsfor dynamic magnetic resonance lymphangiography [89].Gadolinium (Gd) containing polyamidoamine (PAMAM)dendrimers of different sizes and molecular structures(PAMAM-Generation 8(G8), PAMAM-G4 and diaminobu-tane (DAB)-G5) are used as contrast agents. Size andmolecular structure play a great role in distribution and phar-macokinetics of dendrimers. For example, PAMAM-G8 wheninjected intravenously had a comparatively long life in the cir-culatory system with minimum leakage out of the vessels,whereas PAMAM-G4 cleared rapidly from the systemic circu-lation due to rapid renal clearance but had immediate survivalin lymphatic circulation. The smaller sized DAB-G5 showedgreater accumulation and retention in lymph nodes usefulfor lymph node imaging using magnetic resonance lymphog-raphy. Gadomer-17 and Gd-diethyl triamine penta acetic acid(DTPA)-dimeglumine (Magnevist) were evaluated as con-trols. Imaging experiments revealed that all of the reagentsare able to visualize the deep lymphatic system except Gd-(DTPA)-dimeglumine. To visualize the lymphatic vesselsand lymph nodes PAMAM-G8 and DAB-G5 were used,respectively. While PAMAM-G4 provided good contrast ofboth the nodes and connecting vessels, Gadomer-17 wasable to visualize lymph nodes, but not as clearly as Gd-baseddendrimers. Kobayashi also delivered various Gd-PAMAM(PAMAM-G2, G4, G6 and G8) and DAB-G5 dendrimersto the sentinel lymph nodes and evaluated their visualizationwith other nodes. The G6 dendrimer provided excellent opa-cification of sentinel lymph nodes and was able to be absorbedand retained in the lymphatic system [90]. Kobayashi also pro-posed use of quantum dots for labeling cancer cells and den-drimer based optical agents for visualizing lymphaticdrainage and identifying sentinel lymph nodes [91].

3.3.2 Carbon nanotubesCarbon nanotubes (CNTs) are cylindrical nanostructures ofone or several coaxial graphite layers having diameter from1 up to 100 nm and length of microns [92]. These possess var-ious mechanochemical properties like high surface area,mechanical strength, thermal and chemical stability which

Lymphatic system


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


cause them to be versatile carriers for drugs, proteins, radio-logicals and peptides to target tumor tissues. Hydrophilicmulti-walled carbon nanotubes (MWNT) coated with mag-netic NPs (MN-MWNT) have emerged as an effective deliv-ery system for lymphatic targeting. When these NPs injectedsubcutaneously into the left footpad of rats, the left popliteallymph nodes were dyed black after 3 h of administration.Gemcitabine loaded in these particles evaluated for their lym-phatic delivery efficiency and the MN-MWNTs-gemcitabinegroup displayed the maximum concentration of gemcitabinein the lymph nodes of rats [93]. McDevitt et al. synthesizedtumor targeting water soluble CNT constructs by covalentattachment of monoclonal antibodies like rituximab and lin-tuzumab using 1,4,7,10-tetraazacyclododecane-1,4,7,10-tet-raacetic acid (DOTA) as a metal ion chelator while thefluorescent probe was fluorescein. CNT-(111In-DOTA) (rit-uximab) were explicitly targeted a disseminated humanlymphoma in vivo trials compared to the controls CNT(111In-DOTA) (lintuzumab) and 111In-rituximab [94].Murakami and coworkers evaluated the drug delivery effi-

ciency of water dispersed carbon nanohorns in a non-smallcell lung cancer model. PEG-doxorubicin conjugate boundoxidized single-wall carbon nanohorns injected intratumorallyinto mice bearing human non-small cell lung cancer (NCI-H460) caused a significant retardation of tumor growth [95].Shimada et al. described a silica particle based lymphaticdrug delivery system of bleomycin and compared its therapeu-tic efficacy to that of free bleomycin solution in a transplantedtumor model in animals [96]. Activated carbon particles ofaclacinomycin A, adriamycin, mitomycin C and pepleomycinhave also been used by another group for adsorption. A higherlevel of drug concentration was maintained in the activatedcarbon particles than in the solution form [97].

3.3.3 NanocapsulesNanocapsules are submicroscopic colloidal drug carrier sys-tems composed of an oily or aqueous core surrounded by athin polymer membrane. Nanocapsules display advantagesas an active substance carrier as they protect the encapsulateddrugs from the exterior environment and facilitate their con-trolled release [98]. Nanocapsule tends to be the most promis-ing approach for lymphatic targeting because of its possibilityof attaining distinct qualities with an easy manufacturing pro-cess. Nanocapsules coated with hydrophobic polymers couldbe easily captured by lymphatic cells in the body when admin-istered because the hydrophobic particle is generally recog-nized as a foreign substance. The lymphatic targeting abilityof poly isobutylcyanoacrylate nanocapsules encapsulating12-(9-anthroxy) stearic acid upon i.m. administration wasevaluated and compared with three conventional colloidalformulations [99]. An in vivo study in rats proved that poly iso-butylcyanoacrylate nanocapsules are retained more in theright iliac regional lymph nodes in comparison with othercolloidal carriers.

3.3.4 Hybrid nanosystemsHybrid systems use combination of two or more deliveryforms for effective targeting. Feng et al. developed liposomescontaining diethylaminoethyl-dextran, which substantiallyreduced the undesired local retention and promoted thedraining of liposome into rat lymphatics after s.c. injec-tion [100]. Van der Lubben et al. prepared and investigatedthe in vivo efficacy of plasmid DNA loaded chitosan NPsfor nasal mucosal immunization against hepatitis B. ChitosanDNA NPs were prepared by the coacervation process [101], inwhich chitosan-DNA might be taken in by M cell, and trans-ported across the mucosal boundary, thereby transfectingimmune cells within nasal associated lymphoid tissue(NALT) or gut associated lymphoid tissue (GALT) both asimmunoglobulin A (IgA) inductive sites [102].

Another work demonstrates targeting of three peptides con-taining sequences that bind to cell markers expressed in thetumor vasculature (p24-NRP-1 and p39-Flt-1) [103,104].Tumor lymphatics (p47-LyP-1) [105] were tested for their abil-ity to target 3(nitrilotriacetic acid)-ditetradecylamine contain-ing liposomes to s.c. B16-F1 tumors. Significantly, a potentialantitumor effect was seen after administration of doxorubicin-loaded PEG750 liposomes engrafted with p24-NRP-1.Similarly, hybrid liposomes composed of L-dimyristoylphos-phatidylcholine and polyoxyethylene dodecyl ether showedremarkable reduction of tumor volume in model mice havingacute lymphatic leukemia (ALL) [106]. In another study,in vitro cellular uptake of PEG--PLGA nanoparticle withLyP-1 peptide was about four times that of PEG--PLGANPs without LyP-1. In vivo study showed about eight timeslymph node uptake of these NPs in metastasis than that ofNPs without LyP-1, indicating LyP-1 NPs as a promising car-rier for target-specific drug delivery to lymphatic metastatictumors [107].

4. Physicochemical properties of carriers forlymphatic targeting

Physicochemical properties affect the efficiency of particulateuptake into the lymphatic system [15]. These propertiesinclude size, number of particles, surface charge, molecularweight and lipophilicity. A complete sketch of these proper-ties is shown in Figure 2.

4.1 Size of the carrierTransport of particulates into lymphatic vessels is dependenton particle size. The size of a nanomedicine is vital for passivetargeting. Nanocarrier size must be < 200 nm to avoid uptakeby the RES [108]. Due to the poor lymphatic drainage intumors the interstitial fluid pressure increases which correlatesnanocarriers size relationship with the enhanced permeabilityand retention (EPR) effect: larger and long-circulating nano-carriers (100 nm) are more retained in the tumor, whereassmaller molecules easily diffuse [109].

I. Singh et al.


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


The size of the PLGA microparticles has been studied exten-sively with regard to their uptake and transport to lymph nodes.Particles < 10 µm are taken up easier by the Peyer’s patches [110].Size could be an important factor when the particulates areadministered via s.c. injection. Small particles with diametersless than a few nanometers are generally exchanged throughthe blood capillaries whereas larger particles of diameters upto a few tens of nanometers are absorbed into the lymph capillar-ies [111]. The larger the size of the NPs injected subcutaneously,the greater the fraction of the NPs that will be retained locallyand the lesser the fraction that will enter the lymphatic vesseland have a chance of targeting the lymph nodes. Much workhas been performed evaluating the effect of particle size of sub-cutaneously injected liposomes on lymph targeting.When smallneutral liposomes were injected subcutaneously, > 60 -- 70% ofthe liposomes got cleared from the injection site within 24 hwith only 30 -- 40% of the injected dose remaining at the siteof injection [112].

Reddy et al. studied the effect of 20, 45 and 100 nm diam-eter PEG-stabilized polypropylene sulfide particles size onlymphatic uptake, while targeting dendritic cells (DCs) inthe lymph nodes. Of these, 20 nm particles most readilyentered the lymphatics following interstitial injection, whereas20 and 45 nm NPs showed significant retention in lymphnodes at 24, 72, 96 and 120 h post injection [113].Oussoren et al. reported that relative lymph node localizationof small liposomes are much less as compared to the relativelymph node localization of larger liposomes [114]. Micropar-ticles were also studied for their lymph node accumulation.Liu et al. investigated lymphatic distribution in the thoraciccavity as a function of particle size. Pharmacokinetic and lym-phatic distribution studies proved that ~ 2 µm seems to be asuitable size for thoracic lymphatic targeting through i.p.l.administration in a rat model [115].

4.2 Concentration and volumeHigher concentration of particles at the injection sitedecreases their rate of drainage, owing to increased obstruc-tion of their diffusion through the interstitial space [116].This effect was investigated using polystyrene nanospheres of60 nm. Nanospheres were administered in the concentrationranges of 0.05 -- 3.0 mg/ml to the rat model. Lower lymphaticuptake was seen on increasing the concentration of nano-spheres in the injection volume due to slower drainage fromthe injection site. The effect of injection volume has beendemonstrated by injecting oily vehicles intramuscularly tothe rat. Increasing volume of sesame oil accelerated oiltransport into the lymphatic system [117].

4.3 Surface chargeSurface charge studies have been carried out utilizing liposomalcarrier. The surface charge of liposomes affected their lym-phatic uptake from s.c. and i.p. injection sites. Negativelycharged liposomes showed faster drainage than positive lipo-somes after i.p. administration [118]. Swart et al. also studiedthe lymphatic distribution of the negatively charged anti-HIV-1 agents succinylated or aconytilated human serum albu-min (HSA) in rats. At several time points after i.v. injection,samples were taken from the cannulated thoracic duct andthe carotid artery. Distribution of the negatively charged albu-mins to lymph was much more rapid than that of albuminitself and was dependent on the total net negative charge addedto the protein: the half-life times of lymphatic equilibrationwere 15, 30 and 120 min for fluorescein isothiocyanate(FITC)-labeled aconytilated HSA, FITC-labeled succinylatedHSA and FITC-labeled HSA, respectively [119]. Patel also indi-cated that liposome localization in the lymph nodes followed aparticular order: negative > positive > neutral [120], whereas

Physiochemical properties of carriers affectinglymphatic delivery

Size of thecarrier

Surfacemodification

Concentration andvolume

Surfacecharge

Molecularweight

Lipophilicity

Biotin PEG SurfactantsLigand

Lectin Peptides Antigens

Figure 2. Physiochemical properties of carriers affecting lymphatic delivery.

Lymphatic system


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


Oussoren et al. found that liposomes containing positivelycharged lipids had approximately three times more lymphnode localization [114].

4.4 Molecular weightHigher molecular weight molecules have a decreased abilityfor exchange across blood capillaries, and for these heaviermolecules, lymphatic drainage becomes the route of drainagefrom the injection site which shows a linear relationshipbetween the molecular weight of macromolecules and the pro-portion of the dose absorbed by the lymphatics. For a com-pound to be absorbed by the lymphatics the molecularweight should range between 1000 and 16,000 Da [118,121].The molecular weight effect becomes negligible in targetingcolloids to the lymphatic system as the molecular weight ofa colloidal carrier is generally < 1000 Da. Hence, surface func-tionalization should be done to increase the molecular weight,for better lymphatic localization of carriers. Bagby et al. stud-ied the role of molecular weight of hyaluronic acid in lym-phatic targeting and found that hyaluronan with a molecularweight of 74 kDa was determined to be optimal for lymphaticimaging due to its maximal lymphatic uptake and enhancedlymph node retention [122].

4.5 LipophilicityThe most important determinant of the phagocytic responseand lymphatic uptake is the lipophilicity of a carrier [123].Opsonins generally attach to lipophilic rather than hydrophilicsurfaces; hence, the lipophilic particles show increased phago-cytosis [124]. Hydrophobic polystyrene nanospheres adsorbedwith hydrophilic block co-polymers showed drastic reductionin phagocytosis upon i.v. administration [125]. The type of lip-ids also significantly influences intestinal lymphatic absorption.Arachis oil significantly increased lymphatic transport of drugrelative to the other vehicles. Long chain unsaturated fattyacids, such as those in arachis oil, were more successful dueto the increased ability to stimulate chylomicron production.This work was confirmed and developed by Charman et al.,who showed that the rate and extent of lymphatic transportof DDT (1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane), fol-lowing intraduodenal administration from an oleic acid vehi-cle, was faster and higher relative to the triglyceride peanutoil [126]. Caliph et al. showed the lymphatic transport of halo-fantrine in a conscious rat model is highly dependent on thechain length of the co-administered triglyceride lipid. Theextent of mesenteric lymphatic transport of halofantrine(expressed as a percentage of the dose) increased from 2.2 to5.5 to 15.8% following oral administration in short (C4),medium (C8 -- 10) and long (C18) chain triglyceride vehicles,respectively [127]. The influence of the degree of fatty acid unsa-turation (oleic [C18:1], linoleic [C18:2] or linolenic acid[C18:3]) on intestinal lymphatic transport of halofantrinefree base has also been compared [128].

4.6 Surface modification on carriersActive targeting is based on the attachment of the targetingligands (tissue or cell-specific) at the surface of the drugloaded nanocarrier system for appropriate receptor bindingthat are expressed at the target site. The ligand particularlybinds to a receptor overexpressed in particular diseased cellsor tumor vasculature and not expressed by normal cells. Inaddition, targeted receptors should be present uniformly onall targeted cells. Targeting ligands are either mAbs and anti-body fragments or nonantibody ligands (peptidic or not).These can also be termed as ligand targeted therapeutics [129].Surface modification could prove as an effective strategy forpotential targeting to lymphatic system as shown in Figure 3.The influence can be quoted in the following ways.

4.6.1 Surface coating with surfactantsStudies have been reported to determine the ideal nanocarriersurface characteristics for the targeting of drugs to the lymphnodes following s.c. injection. Moghimi et al. have performedstudies of 45 nm polystyrene nanospheres with poloxamerscoating. A range of different poloxamers with varying lengthsof ethylene oxide units have been evaluated. The polystyrenenanospheres with the most effective delivery and retentionin the draining lymph nodes had a poloxamer coating of4 -- 15 ethylene oxide units per chain and a coating thicknessof < 3 nm. These nanospheres have both rapid clearance fromthe s.c. injection site as well as significant retention in thedraining lymph nodes [123]. In another study it was reportedthat lymphatic distribution of interstitially injected poloxamer407-coated nanospheres (45 nm in diameter) is controlled bysurface configuration of the ethylene oxide (EO) segments ofthe adsorbed copolymer. When the equilibrium poloxamerconcentration is at ‡ 75 µg/ml the EO chains become moreclosely packed and project outward from the nanosphere sur-face. These surface-engineered nanospheres drain faster thanthose with EO chains in mushroom configurations into theinitial lymphatic and escape clearance by lymph node macro-phages, reach the systemic circulation and remain in the bloodfor prolonged periods. These experiments provide a rationalapproach for the design and engineering of nano-vehicles foroptimal lymphatic targeting [130].

4.6.2 Surface modification with PEGCoating of a carrier with hydrophilic and sterically stabilizedPEG layer can successfully enhance lymphatic absorptionreducing specific interaction of particle with the interstitialsurrounding and inhibiting the formation of too large particlestructure [131]. Kaminskas et al. reported that the lymphaticdiseases is expected to be improved by enhancing lymphaticdisposition using PEGylation concept [32]. Small liposomescoated with PEG showed greatest clearance from the s.c.injection site with < 40% small 86 nm PEG-coated liposomesremaining at the injection site at 24 h. Larger neutral and neg-atively charged liposomes had a clearance > 60% remaining at

I. Singh et al.


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


the initial s.c. injection site. However, this smaller amount oflarge liposomes that were cleared from the injection site wascompensated by better retention in the lymph node [132].

Zhuang et al. investigated the effect of PEGylation on lymphnode targeting and the immunogenicity of cationic liposome-formulated vaccines. They prepared 1,2-dioleoyl-3-trimethyl-ammoninum propane (DOTAP) cationic liposomes andincorporated them with 1 or 5 mol% of 1,2-distearoyl-sn-glyc-ero-3-phosphoethanolamine (DSPE) -PEG2000 and labeledwith near infrared fluorescent dyes. The in vivo imaging resultsafter s.c. injection showed that incorporation of 1 mol%DSPE-PEG2000 not only accelerated the drainage ofDOTAP liposomes into draining lymph nodes, but also pro-longed their lymph node retention and enhanced liposomeuptake by resident antigen-presenting cells [133]. In anotherstudy it was reported that incorporation of 5 -- 7 mol% mono-methoxypoly-(ethyleneglycol)2000-phosphatidylethanolamine

(mPEG2000-PE) into liposomal lipid bilayer is known to dra-matically enhance the drainage of interstitially injected vesiclesinto the initial lymphatics [134].

Moghimi et al. revealed that interstitially injected immuno-polyethyleneglycol-liposomes can penetrate the thin walledand fenestrated lymphatic microvessels and are subsequentlyconveyed to the regional lymph nodes [135]. Jain et al. pre-pared PEGylated elastic liposomal formulation for lymphatictargeting of zidovudine. Results of biodistribution study indi-cated 27-fold higher accumulation of zidovudine in lymphoidtissues after application of PEGylated elastic liposomes ascompared to free drug. The entrapment of zidovudine intoPEGylated elastic liposomes represents a potential approachfor overcoming the toxicity by its selective uptake in lym-phoid organs. This represents an attractive approach for sus-tained and targeted delivery of zidovudine [136]. PEGylationof poly-L-lysine dendrimers may improve the extent of

Lymph Blood

Microparticles

++

+ +

+

+

+ ++

Nanoparticles

-

-

-

---

Stealth liposome

Liposome

Mannosylated NP

Biotin-avidin NP

Lectin NP

Peptide conjugated NP

Dendrimer

Peyer’s patchesCationic NP

Neutral NP Anionic NP

Lymph node

SLN

Non functionalized NP

Figure 3. Lymph targeting potential of surface modified and unmodified particles. A diagrammatic view illustrating the

propensity of movement of the particles to lymph or blood depending upon their size and surface modifications. All the

surface functionalized particles like lectin conjugated, mannosylated, biotin--avidin conjugated, stealth and peptides have the

tendency to reach lymph when injected in systemic circulation or given orally. Unlike, nonfunctionalized nanoparticles

anionically charged nanoparticles reside only in blood and their fate depends upon the enhanced permeability and

retention effect.

Lymphatic system


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


lymphatic transport by increasing the size of the PEGylateddendrimer complex [137]. Shin et al. studied PEGylated tacro-limus encapsulated PLGA nanopaticles for lymph targeting.They found that PEGylation significantly improved lym-phatic accumulation of tacrolimus and reduced the toxicityof the drug [138].

4.6.3 Surface modification with ligandsCarriers capped with nonspecific human antibodies as ligandsshowed greater lymphatic uptake and lymph node retentioncompared to uncoated ones at the s.c. site. Liposomes coatedwith the antibody IgG have been shown to increase lymphnode localization of liposomes to 4.5% of the injected doseat 1 h [139]. Another method in which the liposomes containpositively charge lipids had approximately two -- three timesthe lymph node localization (up to 3.6% of the injecteddose) than liposomes containing neutral or negatively chargedlipids (1.2% of the injected dose) [112].Kaur et al. prepared zidovudine loaded surface-engineered

liposomes using mannose in order to enhance localization tolymphatics, specifically to lymph node and spleen. The sur-face engineered liposomes appeared to be a promising novelvesicular system for enhanced targeting of zidovudine to lym-phatics in AIDS chemotherapy [140]. Another study demon-strated hepatitis B surface antigen (HBsAg) entrapped dried

liposomes with their surfaces modified with galactose. Phar-macokinetic study in rats showed that galactosylated lipo-somes delivered higher amounts of HBsAg to the regionallymph nodes than other ungalactosylated formulations [141].Lectin is another ligand that can be attached to the carriersfor improved targeting to intestinal lymphatics. Bovine serumalbumin containing acid phosphatase model protein andpolystyrene microspheres conjugated with mouse M-cell-spe-cific Ulex europaeus lectin. Final results indicated that cou-pling of lectin specific to cells of the follicle associatedepithelium can improve the targeting of encapsulated candi-date antigens for delivery to the peyer’s patches of theintestine [142].

Goutayer et al. prepared lipid NPs functionalized for activetargeting to tumors. Tumor targeting ligand like cRGD(cyclic Arg-Gly-Asp) peptide is able to bind withavb3 integrins and improves the accumulation of functional-ized lipid NPs in tumor than that of non-functionalized lipidNPs [143]. Hauff et al. prepared and evaluated L-selectin ligandspecific polymer-stabilized air-filled microparticles for activetargeting of peripheral lymph nodes under normal conditionsin animal models [144].

Yan et al. prepared LyP-1-conjugated PEGylated liposomesfor targeted therapy of lymphatic metastatic tumor. Thein vitro cellular uptake and in vivo near-infrared fluorescence

Table 1. Different ligands/chemicals used for lymphatic targeting.

Ligands/chemicals Delivery system Target site Application Refs.

Folate Folate-PEG-CKK2-DTPAcarrier

Lymphatic metastasized tumor Tumor imaging diagnosisand targeting therapy

[149]

Lectin Nanoparticles Metastatic spread and growthof tumor cell

Anticancer drug delivery [150]

Lectin Microspheres Delivery of antigens to GALT Intestinal delivery [142]

L-selectin Microparticles Active targeting of peripherallymph nodes

Doppler ultrasonographycontrast agent

[144]

PEG Dendrimers, liposomesand nanoparticles

Lymph Vaccine delivery [112,132-138]

Hyaluronan -- Lymphatic system -- [151]

Mannose Liposome Spleen, lymph nodes Antiviral and anticancerdrug delivery

[140]

Galactose Liposome Lymph node Hepatitis B [141]

Alginate/chitosan Microparticles Peyer’s patch Tamoxifen anticancer drug [152]

Negatively charged albumins Microparticles Lymph nodes and lymphaticsystem

Antiviral drug delivery [119]

N-isopropylacrylamide/(MAA) Nanoparticles Thoracic lymph nodes Chemotherapeutic agent [85]

Poly(lactide-co-glycolide) Microparticles Thoracic lymph nodes Chemotherapeutic agent [85]

Block co-polymer ofpoloxamineand poloxamer

Nanospheres Regional lymph nodes -- [123]

LyP-1 Nanoparticles, liposomes Targeted to lymphatic vesselsand lso intumor cells within hypoxic area

Antitumor [107,145]

Avidin-biotin Liposomes Targeting to lymph node Mediastinal lymph nodetargeting

[146]

IgG antibody Liposome Targeting to lymph node Increased lymph noderetention

[124,139]

DTPA: Diethyl triamine penta acetic acid; GALT: Gut associated lymphoid tissue; MAA: Methacrylic acid.

I. Singh et al.


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


imaging results showed that LyP-1 modification increasedliposome uptake by tumor cells and metastatic lymph nodes,but did not increase uptake by normal lymph nodes. Theimmunofluorescence analysis evidenced that LyP-1-conju-gated liposomes were distributed adjacent to tumor lym-phatics and tumor-associated macrophages in metastaticlymph nodes. The pharmacodynamic study suggested thatcompared with unmodified liposomes, LyP-1-conjugatedDOX-loaded liposomes exhibited enhanced inhibition effecton tumor cells in vitro and lymphatic metastatic tumorsin vivo [145]. Luo et al. also formulated LyP-1-conjugatedPEG--PLGA NPs for targeted drug delivery to lymphatic met-astatic tumors. In vitro results showed that the cellular uptakeof LyP-1-NPs was about four times that of PEG--PLGA-NPswithout LyP-1. Similarly, the in vivo data also revealed thatthe uptake of LyP-1-NPs in metastatic lymph nodes wasabout eight times that of NPs [107].

4.6.4 Surface modification with biotinTo improve carrier retention in lymph nodes, a new methodof increasing lymphatic uptake of subcutaneously injectedliposome utilizes the high affinity ligands biotin and avidin.Biotin is a naturally occurring cofactor and avidin is a proteinderived from eggs. Avidin and biotin have extremely highaffinity for each other. For instance, upon injection, the avi-din and the biotin liposomes move into the lymphatic vessels.Biotin liposomes that are migrating through the lymphaticvessels meet with the avidin resulting in an aggregate thatbecomes trapped in the lymph nodes [146,147]. The biotin lipo-some/avidin system has promising potential as therapeuticagent for delivery to lymph nodes. It can be applied notonly to s.c. targeting of lymph nodes but also to intracavitarylymph node targeting [148]. Intraperitoneal administrationusing the avidin/biotin liposome system has potential for thedelivery of anticancer agents in the peritoneum. Differentligands with their application in lymphatic targeting arerepresented in Table 1.

5. Conclusion

Lymphatic transport is a complex process; however, it offersmany potential advantages for targeted drug delivery. In orderto optimize the design of delivery systems a more thoroughunderstanding of the physiological processes and the interac-tion of the delivery systems with the physiological environ-ment is necessary. Chemotherapy holds great promise fortreating patients with lymphatic diseases. Nanotechnologybased systems have opened exciting perspectives towards thedevelopment of new therapeutic options for the treatment ofseveral devastating and complex lymphatic diseases includingcancer and HIV. These systems may improve drug therapyin infected patients as demonstrated by in vitro and in vivoanimal studies. Various nanosystems have shown the abilityto improve pharmacological activity of several drugs, whilereducing their toxicity and potentially simplifying drug

regimens. In addition, these novel formulations provide anumber of advantages for delivery of poor water soluble,unstable and cytotoxic drugs to the lymphatic system. Byoptimizing the preparation procedure and choosing theproper administration route, significant enhancements in bio-availability and lymphatic uptake can be achieved. This articleaims to review the emerging novel drug carriers for targetingthe lymphatic system.

6. Expert opinion

Lymphatic system is geared towards removing excess fluidfrom the tissues and it traverses the lymph nodes. A varietyof diseases affect the lymphatic system early in their timecourse. For instance, many cancers spread by lymphatic dis-semination, and HIV, fungal and bacterial infections arelocated primarily in the lymph nodes. Lymphatic expansionhas been found in various chronic inflammatory disorders,including psoriasis, atopic dermatitis, inflammatory boweldisease and rheumatoid arthritis. Lymphangiogenesis is recog-nized to precede hematological spread in many cancersincluding melanoma, breast, colon and lung and prostate can-cers. Thus, lymph node lymphangiogenesis might serve as asuitable target for imaging approaches for the early detectionof cancer metastases. Giving importance to the lymphaticroute in metastasis, this delivery system may have great poten-tial for targeted delivery of various therapeutic agents totumors and their metastatic lymph nodes. The high preva-lence of lymph node involvement in disease is due to therole of lymphatics in providing the body’s immune response.Targeting this compromised immune system is necessary forHIV, filariasis, leishmaniasis infections and so on. Directintra-lymphatic system administration is not possible like inother modes of systemic administration. Hence, drug and car-rier properties play a pivotal role in targeting lymphatic sys-tem through systemic circulation. However, in per oralroute of administration carriers are directly absorbed fromPeyer’s patches depending upon their surface characteristics.Apart from using lymphatic targeting for therapeutic pur-poses, intestinal lymphatic drug delivery can be used forincreasing bioavailability of drug by avoiding first pass metab-olism and restricting the action of drugs to lymph thereforesustaining the effect of formulation. Although tremendousresearch is being conducted at academic as well as researchlevel for lymphatic drug targeting, the following are certainmajor constraints that still exist:

1) Stability is a prominent factor in designing NPs. It isalways a challenge to formulate NPs with the smallestsize possible but with maximum stability. Stabilityissues become utmost important in the case of surfacefunctionalized NPs.

2) A large amount of time and money have been investedin this field, even though productive clinical trials have

Lymphatic system


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.


not been done to explore market potential for formula-tions of lymphatic diseases.

3) Lymphatic system disposition can be increased pas-sively by exploring different physiochemical propertiesof carriers and intricate lymphatic pathophysiologylike lymphatic drainage in tumors. But active targetingstill remains ineffective due to lack of overexpressedreceptors at these sites except Peyer’s patches.

4) Although many researchers have demonstrated sizedependent absorption of particles in lymphatic system,even then a substantial size range is not established toascertain lymphatic drug disposition.

5) The methods employed for the development of surfacefunctionalized NPs are not commercially productiveand scalability also remains a challenge.

Nanocarrier system can meet the needs for effectivetargeting to lymphatics. Various delivery systems have been

discussed here but lipidic carriers especially liposomes havebeen the carrier of choice to date. The purpose of this reviewis to provide a brief of an improved and effective lympho-tropic system that may prove to be an effective carrier foranti-HIV, anticancer and oral vaccines in the near future.

Acknowledgment

Authors thank Director, IICT and Project Director, NIPERfor encouragement. This work was supported by CSIR undergrant CSC 0302.

Declaration of interest

The authors state no conflict of interest and have received nopayment in preparation of this manuscript.

BibliographyPapers of special note have been highlighted as

either of interest (�) or of considerable interest(��) to readers.

1. Cueni LN, Detmar M. New insights into

the molecular control of the lymphatic

vascular system and its role in disease.

J Invest Dermatol 2006;126(10):2167-77

2. Swartz MA. The physiology of the

lymphatic system. Adv Drug Deliv Rev

2001;50(1):3-20

3. Gerli R, Solito R, Weber E, et al.

Specific adhesion molecules bind

anchoring filaments and endothelial cells

in human skin initial lymphatics.

Lymphology 2000;33(4):148-57

4. Huntington GS, McClure CFW. The

anatomy and development of the jugular

lymph sacs in the domestic cat (Felis

domestica). Am J Anat

1910;10(1):177-312

5. Maby-El Hajjami H, Petrova TV.

Developmental and pathological

lymphangiogenesis: from models to

human disease. Histochem Cell Biol

2008;130(6):1063-78

6. Rinderknecht M, Detmar M. Tumor

lymphangiogenesis and melanoma

metastasis. J Cell Physiol

2008;216(2):347-54

7. Baldwin ME, Stacker SA, Achen MG.

Molecular control of lymphangiogenesis.

Bioessays 2002;24(11):1030-40

8. Givoli D, Doukhovni I, Moghimi S,

et al. Advanced colloid-based systems for

efficient delivery of drugs and diagnostic

agents to the lymphatic tissues.

Prog Biophys Mol Biol

1996;65(3):221-49

9. Weber E, Rossi A, Solito R, et al. Focal

adhesion molecules expression and

fibrillin deposition by lymphatic and

blood vessel endothelial cells in culture.

Microvasc Res 2002;64(1):47-55

10. Schmid-Schonbein GW. The second

valve system in lymphatics.

Lymphat Res Biol 2003;1(1):25-31

11. Sharma R, Wendt JA, Rasmussen JC,

et al. New horizons for imaging

lymphatic function. Ann NY Acad Sci

2008;1131(1):13-36

12. Moore KL, Dalley AF. Clinically

oriented anatomy. Lippincott Williams

& Wilkins; Baltimore, MD, USA: 1999

13. Heller LJ, Mohrman DE. Cardiovascular

physiology. McGraw-Hill; New York: 1981

14. Morton DL, Eilber FR, Joseph WL,

et al. Immunological factors in human

sarcomas and melanomas: a rational basis

for immunotherapy. Ann Surg

1970;172(4):740

15. O’Hagan DT, Christy NM, Davis SS.

Particulates and lymphatic drug delivery.

In: Lymphatic transport of drugs.

Charman WN, Stella VJ, editors.

CRC Press Inc; Boca Raton, FL, USA:

1992. p. 279-315

16. Charman WN, Stella VJ. Lymphatic

transport of drugs. CRC Press Inc; Boca

Raton, FL, USA: 1992

17. Zgraggen S, Ochsenbein AM,

Detmar M. An important role of blood

and lymphatic vessels in inflammation

and allergy. J Allergy (Cairo)

2013;2013:672381

18. Dashkevich A, Heilmann C, Kayser G,

et al. Lymph angiogenesis after lung

transplantation and relation to acute

organ rejection in humans.

Ann Thorac Surg 2010;90(2):406-11

19. Kerjaschki D, Regele HM, Moosberger I,

et al. Lymphatic neoangiogenesis in

human kidney transplants is associated

with immunologically active lymphocytic

infiltrates. J Am Soc Nephrol

2004;15(3):603-12

20. Hanahan D, Weinberg RA. The

hallmarks of cancer. Cell

2000;100(1):57-70

21. Skobe M, Hawighorst T, Jackson DG,

et al. Induction of tumor

lymphangiogenesis by VEGF-C promotes

breast cancer metastasis. Nat Med

2001;7(2):192-8

22. Yonemura Y, Endo Y, Fujita H, et al.

Role of vascular endothelial growth factor

C expression in the development of

lymph node metastasis in gastric cancer.

Clin Cancer Res 1999;5(7):1823-9

23. McColl BK, Loughran SJ, Davydova N,

et al. Mechanisms of lymphangiogenesis:

targets for blocking the metastatic spread

of cancer. Curr Cancer Drug Targets

2005;5(8):561-71

24. Torabi M, Aquino SL,

Harisinghani MG. Current concepts in

lymph node imaging. J Nucl Med

2004;45(9):1509-18

I. Singh et al.


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.

www.ncbi.nlm.nih.gov/pubmed/16983326?dopt=Abstract






















































25. Farrell MA, McAdams HP, Herndon JE,

et al. Non-small cell lung cancer: FDG

PET for nodal staging in patients with

stage I disease. Radiology

2000;215(3):886-90

26. Kidd EA, Siegel BA, Dehdashti F, et al.

Lymph node staging by positron

emission tomography in cervical cancer:

relationship to prognosis. J Clin Oncol

2010;28(12):2108-13

27. Busby JE, Evans CP. Old friends, new

ways: revisiting extended

lymphadenectomy and neoadjuvant

chemotherapy to improve outcomes.

Curr Opin Urol 2004;14(5):251-7

28. Shiozawa M, Kobayashi S, Sato Y, et al.

Magnetic resonance lymphography of

sentinel lymph nodes in patients with

breast cancer using superparamagnetic

iron oxide: a feasibility study.

Breast Cancer 2012;

doi: 10.1007/s12282-012-0401-y

29. Schipper R-J, Smidt ML,

van Roozendaal LM, et al. Noninvasive

nodal staging in patients with breast

cancer using gadofosveset-enhanced

magnetic resonance imaging: a feasibility

study. Invest Radiol 2013;48(3):134-9

30. Bumb A, Regino CAS, Egen JG, et al.

Trafficking of a dual-modality magnetic

resonance and fluorescence imaging

superparamagnetic iron oxide-based

nanoprobe to lymph nodes.

Mol Imaging Biol 2011;13(6):1163-72

31. Dunne AA, Boerner HG, Kukula H,

et al. Block copolymer carrier systems for

translymphatic chemotherapy of lymph

node metastases. Anticancer Res

2007;27(6B):3935-40

32. Kaminskas LM, Ascher DB,

McLeod VM, et al. PEGylation of

interferon alpha2 improves lymphatic

exposure after subcutaneous and

intravenous administration and improves

antitumour efficacy against lymphatic

breast cancer metastases.

J Control Release 2013;168(2):200-8

. States that treatment of lymphatic

diseases is expected to be improved by

enhancing lymphatic disposition.

33. Gagne JF, Desormeaux A, Perron S,

et al. Targeted delivery of indinavir to

HIV-1 primary reservoirs with

immunoliposomes.

Biochim Biophys Acta

2002;1558(2):198-210

34. Cohen OJ, Pantaleo G, Lam GK, et al.

Studies on lymphoid tissue from HIV-

infected individuals: implications for the

design of therapeutic strategies.

Springer Semin Immunopathol

1997;18(3):305-22

35. Feller L, Masipa J, Wood N, et al. The

prognostic significance of facial

lymphoedema in HIV-seropositive

subjects with Kaposi sarcoma.

AIDS Res Ther 2008;5:2

36. Spiegel H, Herbst H, Niedobitek G,

et al. Follicular dendritic cells are a major

reservoir for human immunodeficiency

virus type 1 in lymphoid tissues

facilitating infection of CD4+ T-helper

cells. Am J Pathol 1992;140(1):15

37. Desormeaux A, Bergeron MG.

Lymphoid tissue targeting of anti-HIV

drugs using liposomes. Methods Enzymol

2005;391:330-51

38. Horiike M, Iwami S, Kodama M, et al.

Lymph nodes harbor viral reservoirs that

cause rebound of plasma viremia in SIV-

infected macaques upon cessation of

combined antiretroviral therapy. Virology

2012;423(2):107-18

39. Berry CC. Intracellular delivery of

nanoparticles via the HIV-1 tat peptide.

Nanomedicine 2008;3(3):357-65

40. Chakraborty S, Gurusamy M,

Zawieja DC, et al. Lymphatic filariasis:

Perspectives on lymphatic remodeling

and contractile dysfunction in filarial

disease pathogenesis. Microcirculation

2013;20(5):349-64

41. El Setouhy M, Ramzy RMR, Ahmed ES,

et al. A randomized clinical trial

comparing single- and multi-dose

combination therapy with

diethylcarbamazine and albendazole for

treatment of bancroftian filariasis. Am J

Trop Med Hyg 2004;70(2):191-6

42. Ali M, Afzal M, Verma M, et al.

Improved antifilarial activity of

ivermectin in chitosan-alginate

nanoparticles against human lymphatic

filarial parasite, Brugia malayi.

Parasitol Res 2013;112:1-11

43. Dixon D, Terry C, Meselson M, et al.

Infection bacteria for anthrax. N Engl

J Med 1999;341:815-26

44. Jernigan JA, Stephens DS, Ashford DA,

et al. Bioterrorism-related inhalational

anthrax: the first 10 cases reported in the

United States. Emerg Infect Dis

2001;7(6):933

45. Ilgazli A, Boyaci H, Basyigit I, et al.

Extrapulmonary tuberculosis: clinical and

epidemiologic spectrum of 636 cases.

Arch Med Res 2004;35(5):435-41

46. Basaraba RJ, Smith EE, Shanley CA,

et al. Pulmonary lymphatics are primary

sites of Mycobacterium tuberculosis

infection in guinea pigs infected by

aerosol. Infect Immun

2006;74(9):5397-401

47. Marais BJ, Gie RP, Schaaf HS, et al.

The natural history of childhood intra-

thoracic tuberculosis: a critical review of

literature from the pre-chemotherapy era.

Int J Tuberc Lung Dis

2004;8(4):392-402

48. Tian T, Woodworth J, Skold M, et al.

In vivo depletion of CD11c+ cells delays

the CD4+ T cell response to

Mycobacterium tuberculosis and

exacerbates the outcome of infection.

J Immunol 2005;175(5):3268-72

49. Romero EL, Morilla MJ. Drug delivery

systems against leishmaniasis? Still an

open question. Expert Opin Drug Deliv

2008;5(7):805-23

50. Ahsan F, Rivas IP, Khan MA, et al.

Targeting to macrophages: role of

physicochemical properties of particulate

carriers-liposomes and microspheres-on

the phagocytosis by macrophages.

J Control Release 2002;79(1-3):29-40

51. Gupta PK, Hung CT. Albumin

microspheres. II: applications in drug

delivery. J Microencapsul

1989;6(4):463-72

52. Sanchez-Brunete JA, Dea MA, Rama S,

et al. Influence of the vehicle on the

properties and efficacy of microparticles

containing amphotericin B.

J Drug Target 2005;13(4):225-33

53. Hashida M, Egawa M, Muranishi S,

et al. Role of intramuscular

administration of water-in-oil emulsions

as a method for increasing the delivery of

anticancer agents to regional lymphatics.

J Pharmacokinet Biopharm

1977;5(3):225-39

54. Yoshimura K, Nunomura M,

Takiguchi N, et al. Evaluation of

endoscopic pirarubicin-Lipiodol emulsion

injection therapy for gastric cancer

[article in Japanese]. Gan To

Kagaku Ryoho 1996;23:1519-22

55. Wang S, Yang R, Yao H, et al. In vivo

lymphatic targeting of methylene blue

with microemulsion and multiple

microemulsion. Drug Deliv

2009;16(7):371-7

Lymphatic system


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.







































































































56. Hauss DJ, Mehta SC, Radebaugh GW.

Targeted lymphatic transport and

modified systemic distribution of CI-976,

a lipophilic lipid-regulator drug, via a

formulation approach. Int J Pharm

1994;108(2):85-93

57. Segal A, Gregoriadis G, Black C.

Liposomes as vehicles for the local release

of drugs. Clin Sci Mol Med

1975;49(2):99

58. Sajja HK, East MP, Mao H, et al.

Development of multifunctional

nanoparticles for targeted drug delivery

and non-invasive imaging of therapeutic

effect. Curr Drug Discov Technol

2009;6(1):43

59. Sheue Nee Ling S, Magosso E,

Abdul Karim Khan N, et al. Enhanced

oral bioavailability and intestinal

lymphatic transport of a hydrophilic drug

using liposomes. Drug Dev Ind Pharm

2006;32(3):335-45

60. Latimer P, Menchaca M, Snyder RM,

et al. Aerosol delivery of liposomal

formulated paclitaxel and vitamin E

analog reduces murine mammary tumor

burden and metastases. Exp Biol Med

2009;234(10):1244-52

61. Lawson KA, Anderson K, Snyder RM,

et al. Novel vitamin E analogue and

9-nitro-camptothecin administered as

liposome aerosols decrease syngeneic

mouse mammary tumor burden and

inhibit metastasis.

Cancer Chemother Pharmacol

2004;54(5):421-31

62. Bermudez LE. Use of liposome

preparation to treat mycobacterial

infections. Immunobiology

1994;191(4):578-83

63. Vaghasiya H, Kumar A, Sawant K.

Development of solid lipid nanoparticles

based controlled release system for

topical delivery of terbinafine

hydrochloride. Eur J Pharm Sci

2013;49(2):311-22

64. Harivardhan Reddy L, Sharma RK,

Chuttani K, et al. Influence of

administration route on tumor uptake

and biodistribution of etoposide loaded

solid lipid nanoparticles in Dalton’s

lymphoma tumor bearing mice.


65. Paliwal R, Rai S, Vaidya B, et al. Effect

of lipid core material on characteristics of

solid lipid nanoparticles designed for oral

lymphatic delivery. Nanomedicine

2009;5(2):184-91

66. Zara GP, Bargoni A, Cavalli R, et al.

Pharmacokinetics and tissue distribution

of idarubicin-loaded solid lipid

nanoparticles after duodenal

administration to rats. J Pharm Sci

2002;91(5):1324-33

67. Aji Alex MR, Chacko AJ, Jose S, et al.

Lopinavir loaded solid lipid nanoparticles

(SLN) for intestinal lymphatic targeting.

Eur J Pharm Sci 2011;42(1):11-18

68. Videira MA, Botelho M, Santos AC,

et al. Lymphatic uptake of pulmonary

delivered radiolabelled solid lipid

nanoparticles. J Drug Target

2002;10(8):607-13

69. Lu B, Xiong S-B, Yang H, et al. Solid

lipid nanoparticles of mitoxantrone for

local injection against breast cancer and

its lymph node metastases. Eur J

Pharm Sci 2006;28(1):86-95

70. Domb AJ, Khan W. Biodegradable

polymers as drug carrier systems. In:

Dumitriu S, Popa C, editors. Polymeric

Biomaterials. CRC Press; USA:

2013. p. 135-76

71. Khan W, Hosseinkhani H, Ickowicz D,

et al. Polysaccharide gene transfection

agents. Acta Biomater

2012;8(12):4224-32

72. Khan W, Muthupandian S, Domb AJ.

Cationic polymers for the delivery of

therapeutic nucleotides. In: Peer D,

editor. Nanotechnology for the delivery

of therapeutic nucleic acids. Pan Stanford

Publishing; 2013. p. 27-56

73. Khan W, Muthupandian S, Farah S,

et al. Biodegradable polymers derived

from amino acids. Macromol Biosci

2011;11(12):1625-36

74. Bansal P, Verma S, Khan W, et al.

Global patent and technological status of

biodegradable polymers in drug delivery

and tissue engineering. In: Biodegradable

polymers in clinical use and clinical

development. Domb AJ, Neeraj Kumar,

editors, John Wiley & Sons, Inc;

Hoboken, NJ, USA: 2011. p. 665-725

75. Khan W, Yadav D, Domb AJ, et al.

Collagen. Biodegradable polymers in

clinical use and clinical development.

John Wiley & Sons, Inc; Hoboken, NJ,

USA: 2011. p. 59-89

76. Bhatnagar A, Singh AK, Singh T, et al.

Inflammation imaging using Tc-99m

dextran. Clin Nucl Med

1998;23(2):123-4

77. Takakura Y, Matsumoto S, Hashida M,

et al. Enhanced lymphatic delivery of

mitomycin C conjugated with dextran.

Cancer Res 1984;44(6):2505-10

78. Cai S, Xie Y, Bagby TR, et al.

Intralymphatic chemotherapy using a

hyaluronan--cisplatin conjugate.

J Surg Res 2008;147(2):247-52

79. Khan W, Sharma SS, Kumar N.

Bioanalytical method development,

pharmacokinetics, and toxicity studies of

paromomycin and paromomycin loaded

in albumin microspheres.

Drug Test Anal 2013;5(6):453-60

80. Das S, Khan W, Mohsin S, et al.

Miltefosine loaded albumin

microparticles for treatment of visceral

leishmaniasis: formulation development

and in vitro evaluation.

Polym Adv Technol 2011;22(1):172-9

81. Khan W, Kumar N. Characterization,

thermal stability studies, and analytical

method development of Paromomycin

for formulation development.

Drug Test Anal 2011;3(6):363-72

82. Khan W, Kumar R, Singh S, et al.

Paromomycin-loaded albumin

microspheres: efficacy and stability

studies. Drug Test Anal

2013;5(6):468-73

83. Hawley AE, Illum L, Davis SS. Lymph

node localisation of biodegradable

nanospheres surface modified with

poloxamer and poloxamine block

co-polymers. FEBS Lett

1997;400(3):319-23

84. Kumanohoso T, Natsugoe S,

Shimada M, et al. Enhancement of

therapeutic efficacy of bleomycin by

incorporation into biodegradable poly-d,

l-lactic acid.

Cancer Chemother Pharmacol

1997;40(2):112-16

85. Liu J, Wong HL, Moselhy J, et al.

Targeting colloidal particulates to

thoracic lymph nodes. Lung Cancer

2006;51(3):377-86

86. Maincent P, Thouvenot P, Amicabile C,

et al. Lymphatic targeting of polymeric

nanoparticles after intraperitoneal

administration in rats. Pharm Res

1992;9(12):1534-9

87. Liggins RT, D’Amours S, Demetrick JS,

et al. Paclitaxel loaded poly (L-lactic

acid) microspheres for the prevention of

intraperitoneal carcinomatosis after a

I. Singh et al.


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.

























































































surgical repair and tumor cell spill.

Biomaterials 2000;21(19):1959-69

88. Ziraksaz Z, Nomani A, Soleimani M,

et al. Evaluation of cationic dendrimer

and lipid as transfection reagents of short

RNAs for stem cell modification.

Int J Pharm 2013;448(1):231-8

89. Kobayashi H, Kawamoto S, Choyke PL,

et al. Comparison of dendrimer-based

macromolecular contrast agents for

dynamic micro-magnetic resonance

lymphangiography. Magn Reson Med

2003;50(4):758-66

90. Kobayashi H, Kawamoto S, Bernardo M,

et al. Delivery of gadolinium-labeled

nanoparticles to the sentinel lymph node:

comparison of the sentinel node

visualization and estimations of intra-

nodal gadolinium concentration by the

magnetic resonance imaging.


91. Kobayashi H, Ogawa M, Kosaka N,

et al. Multicolor imaging of lymphatic

function with two nanomaterials:

quantum dot-labeled cancer cells and

dendrimer-based optical agents.

Nanomedicine 2009;4(4):411-19

92. Boncel S, Zajac P, Koziol KKK.

Liberation of drugs from multi-wall

carbon nanotube carriers.

J Control Release 2013;169(1-2):126-40

93. Yang D, Yang F, Hu J, et al.

Hydrophilic multi-walled carbon

nanotubes decorated with magnetite

nanoparticles as lymphatic targeted drug

delivery vehicles. Chem Commun

2009(29):4447-9

94. McDevitt MR, Chattopadhyay D,

Kappel BJ, et al. Tumor targeting with

antibody-functionalized, radiolabeled

carbon nanotubes. J Nucl Med

2007;48(7):1180-9

95. Murakami T, Sawada H, Tamura G,

et al. Water-dispersed single-wall carbon

nanohorns as drug carriers for local

cancer chemotherapy. Nanomedicine

2008;3(4):453-63

96. Shimada M, Natsugoe S, Aikou T.

Enhanced efficacy of Bleomycin adsorbed

on silica particles against lymph node

metastasis derived from a transplanted

tumor. Anticancer Res 1995;15(1):109

97. Lucci A, Turner RR, Morton DL.

Carbon dye as an adjunct to isosulfan

blue dye for sentinel lymph node

dissection. Surgery 1999;126(1):48-53

98. Park M-J, Balakrishnan P, Yang S-G.

Polymeric nanocapsules with SEDDS oil-

core for the controlled and enhanced oral

absorption of cyclosporine. Int J Pharm

2013;441(1-2):757-64

99. Nishioka Y, Yoshino H. Lymphatic

targeting with nanoparticulate system.

Adv Drug Deliv Rev 2001;47(1):55-64

100. Feng L, Zhang L, Liu M, et al. Roles of

dextrans on improving lymphatic

drainage for liposomal drug delivery

system. J Drug Target

2010;18(3):168-78

101. Van der Lubben I, Verhoef J,

Borchard G, et al. Chitosan for mucosal

vaccination. Adv Drug Deliv Rev

2001;52(2):139-44

102. Janes K, Calvo P, Alonso M.

Polysaccharide colloidal particles as

delivery systems for macromolecules.


103. An P, Lei H, Zhang J, et al. Suppression

of tumor growth and metastasis by a

VEGFR-1 antagonizing peptide

identified from a phage display library.

Int J Cancer 2004;111(2):165-73

104. Starzec A, Vassy R, Martin A, et al.

Antiangiogenic and antitumor activities

of peptide inhibiting the vascular

endothelial growth factor binding to

neuropilin-1. Life Sci 2006;79(25):2370

105. Laakkonen P, Porkka K, Hoffman JA,

et al. A tumor-homing peptide with a

targeting specificity related to lymphatic

vessels. Nat Med 2002;8(7):751-5

106. Ichihara H, Ueno J, Umebayashi M,

et al. Chemotherapy with hybrid

liposomes for acute lymphatic leukemia

leading to apoptosis in vivo. Int J Pharm

2011;406(1-2):173-8

107. Luo G, Yu X, Jin C, et al.

LyP-1-conjugated nanoparticles for

targeting drug delivery to lymphatic

metastatic tumors. Int J Pharm

2010;385(1):150-6

108. Jain RK. Delivery of molecular and

cellular medicine to solid tumors.

Adv Drug Deliv Rev

2001;46(1-3):149-68

109. Pirollo KF, Chang EH. Does a targeting

ligand influence nanoparticle tumor

localization or uptake? Trends Biotechnol

2008;26(10):552-8

110. Barrett ADT, Stanberry LR. Vaccines for

biodefense and emerging and neglected

diseases. Academic Press; The

Netherlands: 2009

111. Bergqvist L, Strand S, Haftstrom L, et al.

The characterisation of radio colloids

used for administration to the lymphatic

system. In: Davis SS, Ilium L,

McVic JG, Tomlinson E, editors.

Microspheres and drug therapy:

pharmaceutical immunological and

medical aspects. Elsevier; Amsterdam,

The Netherlands: 1984. p. 263-7

112. Oussoren C, Storm G. Lymphatic uptake

and biodistribution of liposomes after

subcutaneous injection: III. Influence of

surface modification with poly

(ethyleneglycol). Pharm Res

1997;14(10):1479-84

113. Reddy ST, van der Vlies AJ, Simeoni E,

et al. Exploiting lymphatic transport and

complement activation in nanoparticle

vaccines. Nat Biotechnol

2007;25(10):1159-64

114. Oussoren C, Zuidema J,

Crommelin DJA, et al. Lymphatic

uptake and biodistribution of liposomes

after subcutaneous injection: II. Influence

of liposomal size, lipid composition and

lipid dose. Biochim Biophys Acta

1997;1328(2):261-72

115. Liu J, Reilly RM, Scollard D, et al.

Effect of particle size on the

pharmacokinetics and distribution of

111In-aminopolystyrene microspheres for

intrapleural lymphatic targeting. AACR

Meeting Abstracts; 2005. p. 335

116. Bettendorf U. Electronmicroscopic

studies on the peritoneal resorption of

intraperitoneally injected latex particles

via the diaphragmatic lymphatics.

Lymphology 1979;12(2):66

117. Muranishi S. Lymphatic delivery of drugs

and its application to cancer

chemotherapy (author’s transl)].

Yakugaku Zasshi 1980;100(7):687

118. Hirano K, Hunt CA, Strubbe A, et al.

Lymphatic transport of liposome-

encapsulated drugs following

intraperitoneal administration--effect of

lipid composition. Pharm Res

1985;2(6):271-8

119. Swart PJ, Beljaars L, Kuipers ME, et al.

Homing of negatively charged albumins

to the lymphatic system: general

implications for drug targeting to

peripheral tissues and viral reservoirs.

Biochem Pharmacol 1999;58(9):1425-35

120. Patel HM, Boodle KM,

Vaughan-Jones R. Assessment of the

potential uses of liposomes for

lymphoscintigraphy and lymphatic drug

Lymphatic system


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.







































































































delivery. Failure of 99m-technetium

marker to represent intact liposomes in

lymph nodes. Biochim Biophys Acta

1984;801(1):76-86

121. Supersaxo A, Hein WR, Steffen H.

Effect of molecular weight on the

lymphatic absorption of water-soluble

compounds following subcutaneous

administration. Pharm Res

1990;7(2):167-9

122. Bagby TR, Cai S, Duan S, et al. Impact

of molecular weight on lymphatic

drainage of a biopolymer-based imaging

agent. Pharmaceutics 2012;4(2):276-95

123. Moghimi S, Hawley A, Christy N, et al.

Surface engineered nanospheres with

enhanced drainage into lymphatics and

uptake by macrophages of the regional

lymph nodes. FEBS Lett

1994;344(1):25-30

124. Patel H. Serum opsonins and liposomes:

their interaction and opsonophagocytosis.

Crit Rev Ther Drug Carrier Syst

1992;9(1):39-90

125. Florence AT, Attwood D.

Physicochemical principles of pharmacy.

Pharmaceutical Press; London, UK: 2011

126. Charman WNA, Noguchi T, Stella VJ.

An experimental system designed to study

the in situ intestinal lymphatic transport

of lipophilic drugs in anesthetized rats.

Int J Pharm 1986;33(1):155-64

127. Caliph SM, Charman WN, Porter CJH.

Effect of short, medium, and long chain

fatty acid based vehicles on the absolute

oral bioavailability and intestinal

lymphatic transport of halofantrine and

assessment of mass balance in lymph

cannulated and noncannulated rats.

J Pharm Sci 2000;89(8):1073-84

128. Holm R, Mullertz A, Pedersen GP, et al.

Comparison of the lymphatic transport

of halofantrine administered in disperse

systems containing three different

unsaturated fatty acids. Pharm Res

2001;18(9):1299-304

129. Gosk S, Moos T, Gottstein C, et al.

VCAM-1 directed immunoliposomes

selectively target tumor vasculature in

vivo. Biochim Biophys Acta

2008;1778(4):854-63

130. Moghimi SM. Modulation of lymphatic

distribution of subcutaneously injected

poloxamer 407-coated nanospheres: the

effect of the ethylene oxide chain

configuration. FEBS Lett

2003;540(1):241-4

131. Oussoren C, Storm G. Liposomes to

target the lymphatics by subcutaneous

administration. Adv Drug Deliv Rev

2001;50(1):143-56

132. Phillips WT, Andrews T, Liu H, et al.

Evaluation of [(99m) Tc] liposomes as

lymphoscintigraphic agents: comparison

with [(99m) Tc] sulfur colloid and

[(99m) Tc] human serum albumin.

Nucl Med Biol 2001;28(4):435

133. Zhuang Y, Ma Y, Wang C, et al.

PEGylated cationic liposomes robustly

augment vaccine-induced immune

responses: role of lymphatic trafficking

and biodistribution. J Control Release

2012;159(1):135-42

134. Allen TM, Hansen CB, Guo LSS.

Subcutaneous administration of

liposomes: a comparison with the

intravenous and intraperitoneal routes of

injection. Biochim Biophys Acta

1993;1150(1):9-16

135. Moghimi M, Moein Moghimi S.

Lymphatic targeting of immuno-PEG-

liposomes: evaluation of antibody-

coupling procedures on lymph node

macrophage uptake. J Drug Target

2008;16(7-8):7-8

136. Jain S, Tiwary AK, Jain NK. PEGylated

elastic liposomal formulation for

lymphatic targeting of zidovudine.

Curr Drug Deliv 2008;5(4):275-81

137. Kaminskas LM, Kota J, McLeod VM,

et al. PEGylation of polylysine

dendrimers improves absorption and

lymphatic targeting following SC

administration in rats. J Control Release

2009;140(2):108-16

138. Shin S-B, Cho H-Y, Kim D-D, et al.

Preparation and evaluation of tacrolimus-

loaded nanoparticles for lymphatic

delivery. Eur J Pharm Biopharm

2010;74(2):164-71

139. Mangat S, Patel HM. Lymph node

localization of non-specific antibody-

coated liposomes. Life Sci

1985;36(20):1917-25

140. Kaur CD, Nahar M, Jain NK.

Lymphatic targeting of zidovudine using

surface-engineered liposomes.

J Drug Target 2008;16(10):798-805

141. Kim CK, Jeong EJ. Enhanced lymph

node delivery and immunogenicity of

hepatitis B surface antigen entrapped in

galactosylated liposomes. Int J Pharm

1997;147(2):143-51

142. Akande J, Yeboah KG, Addo RT, et al.

Targeted delivery of antigens to the gut-

associated lymphoid tissues: 2. Ex vivo

evaluation of lectin-labelled albumin

microspheres for targeted delivery of

antigens to the M-cells of the Peyer’s

patches. J Microencapsul

2010;27(4):325-36

143. Goutayer M, Dufort S, Josserand V,

et al. Tumor targeting of functionalized

lipid nanoparticles: assessment by in vivo

fluorescence imaging. Eur J

Pharm Biopharm 2010;75(2):137-47

144. Hauff P, Reinhardt M, Briel A, et al.

Molecular targeting of lymph nodes with

L-selectin ligand-specific US contrast

agent: a feasibility study in mice and

dogs1. Radiology 2004;231(3):667-73

145. Yan Z, Wang F, Wen Z, et al.

LyP-1-conjugated PEGylated liposomes:

a carrier system for targeted therapy of

lymphatic metastatic tumor.


.. States the combined impact of peptide

and PEGylation mediated lymphatic

targeting of metastatic tumor.

146. Medina LA, Calixto SM, Klipper R,

et al. Avidin/biotin-liposome system

injected in the pleural space for drug

delivery to mediastinal lymph nodes.

J Pharm Sci 2004;93(10):2595-608

147. Medina LA, Klipper R, Phillips WT, et al.

Pharmacokinetics and biodistribution of

[111In]-avidin and [99mTc]-biotin-

liposomes injected in the pleural space for

the targeting of mediastinal nodes.

Nucl Med Biol 2004;31(1):41-51

148. Phillips WT, Klipper R, Goins B. Novel

method of greatly enhanced delivery of

liposomes to lymph nodes. J Pharmacol

Exp Ther 2000;295(1):309-13

149. Gu B, Xie C, Zhu J, et al.

Folate-PEG-CKK 2-DTPA, A potential

carrier for lymph-metastasized tumor

targeting. Pharm Res 2010;27(5):933-42

150. Sinha R, Kim GJ, Nie S, et al.

Nanotechnology in cancer therapeutics:

bioconjugated nanoparticles for drug

delivery. Mol Cancer Ther

2006;5(8):1909-17

151. Drobnik J. Hyaluronan in drug delivery.


152. Coppi G, Iannuccelli V. Alginate/

chitosan microparticles for tamoxifen

delivery to the lymphatic system.

Int J Pharm 2009;367(1):127-32

I. Singh et al.


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.






































































































AffiliationIndu Singh1, Rajan Swami1, Wahid Khan*1 &

Ramakrishna Sistla†1,2

†,*Authors for correspondence1National Institute of Pharmaceutical Education

& Research (NIPER), Department of

Pharmaceutics, Hyderabad 500037, India

Tel: +91 40 27193004, +91 40 23073741;

Fax: +91 40 27193753, +91 40 23073751;

E-mail: [email protected]; [email protected] Institute of Chemical Technology,

Medicinal Chemistry & Pharmacology Division,

Hyderabad 500067, India

Lymphatic system


Exp

ert O

pin.

Dru

g D

eliv

. Dow

nloa

ded

from

info

rmah

ealth

care

.com

by

Uni

vers

ity o

f G

roni

ngen

on

05/0

2/14

For

pers

onal

use

onl

y.

mailto:[email protected]

mailto:[email protected]


Lymphatic system: a prospective area for advanced targeting of particulate drug carriers

Documents

Transcript of Lymphatic system: a prospective area for advanced targeting of particulate drug carriers