Immunoadjuvant chemotherapy of visceral leishmaniasis in hamsters using Amphotericin B encapsulated nano-emulsion template based chitosan nanocapsules

Abstract

The accessible treatment options for life-threatening neglected visceral leishmaniasis (VL) disease have problems regarding efficacy, stability, adverse effects and cost, making treatment a complex issue. Herein, we formulated nanometric amphotericin B (AmB) encapsulated chitosan-nanocapsules (CNC-AmB) using polymer deposition technique mediated by nano-emulsion template fabrication. CNC-AmB exhibited good steric stability in vitro where chitosan content was found to be efficient in preventing their destabilization in the presence of protein and Ca+2. Toxicity study on J774A model cell line and erythrocytes revealed less toxicity of CNC-AmB compared to commercialized AmB formulations such as Fungizone® and AmBisome®. Experimental results of in vitro (macrophage amastigote system, IC50 = 0.19±0.04 µg AmB/ml) and in vivo (Leishmania donovani infected hamsters, 86.1±2.08% parasite inhibition) in conjunction with effective internalization by macrophages illustrated the efficacy of CNC-AmB to augment antileishmanial property. Quantitative mRNA analysis by RT-PCR showed that improved effect was synergized with up regulated Tumor Necrosis Factor-α (TNF-α), Interleukin-12 (IL-12) and inducible nitric oxide synthase, and down regulated Transforming Growth Factor-β (TGF- β), IL-10 and IL-4. These research findings suggest that developed cost-effective CNC-AmB immunoadjuvant chemotherapeutic delivery system could be a viable alternative to the current high-cost commercial lipid based formulations