Coating doxorubicin-loaded nanocapsules with alginate enhances therapeutic efficacy against Leishmania in hamsters by inducing Th1-type immune responses.
OBJECTIVE
The aim of the present study was to evaluate the immunomodulatory and chemotherapeutic potential of alginate-(SA) coated nanocapsule (NCs) loaded with doxorubicin (SA-NCs-DOX) against visceral leishmaniasis in comparison with nano-emulsions containing doxorubicin (NE-DOX).


METHODS
NE-DOX was prepared using low-energy emulsification methods. Stepwise addition of protamine sulphate and SA in a layer-by-layer manner was used to form SA-NCs-DOX. SA-NCs-DOX, NE-DOX and Free DOX were compared for their cytotoxicity against Leishmania donovani-infected macrophages in vitro and generation of T-cell responses in infected hamsters in vivo.


RESULTS
Size and ζ potential of the NE-DOX and SA-NCs-DOX formulations were 310 ± 2.1 nm and (-)32.6 ± 2.1 mV, 342 ± 4.1 nm and (-)29.3 ± 1.2 mV respectively. SA-NCs-DOX was better (1.5 times) taken up by J774A.1 macrophages compared with NE-DOX. SA-NCs -DOX showed greater efficacy than NE-DOX against intramacrophagic amastigotes. SA-NCs-DOX treatment exhibited enhanced apoptotic efficiency than NE-DOX and free DOX as evident by cell cycle analysis, decrease in mitochondrial membrane potential, ROS and NO production. T-cell responses, when assessed through lymphoproliferative responses, NO production along with enhanced levels of iNOS, TNF-α, IFN-γ and IL-12 were found to be up-regulated after SA-NCs-DOX, compared with responses to NE-DOX in vivo. Parasitic burden was decreased in Leishmania-infected hamsters treated with SA-NCs-DOX, compared with NE-DOX.


CONCLUSIONS
Our results provide insights into the development of an alternative approach to improved management of leishmaniasis through a combination of chemotherapy with stimulation of the innate immune system.
Pharmaceutics Division, CSIR-Central Drug Research Institute, BS-10/1 sector-10 Jankipuram Extension, Lucknow, India.
S
S
Kansal
R
R
Tandon
A
A
Verma
P
P
Misra
A K
AK
Choudhary
R
R
Verma
P R P
PR
Verma
A
A
Dube
P R
PR
Mishra
D000464:Alginates / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D000981:Antiprotozoal Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D006224:Cricetinae; D003630:Daunorubicin / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D020723:Glucuronic Acid / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D006603:Hexuronic Acids / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D007893:Leishmania donovani / Q000187:drug effects* / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000469:parasitology; D008297:Male; D051379:Mice; D053769:Nanocapsules / Q000737:chemistry*; D018417:Th1 Cells / Q000187:drug effects* / Q000276:immunology
D000464:Alginates; D000981:Antiprotozoal Agents; D020099:Coated Materials, Biocompatible; D006603:Hexuronic Acids; D053769:Nanocapsules; D020723:Glucuronic Acid; D003630:Daunorubicin