Covalent functionalized Self-assembled Lipo-polymerosome bearing Amphotericin B for better management of leishmaniasis and its toxicity evaluation

Abstract

Amphotericin B remains the preferred choice for leishmanial infection, but has limited clinical applications due to substantial dose limiting toxicities. In the present work, AmB has been formulated in Lipo-polymerosome (L-Psome) by spontaneous self-assembly of synthesized glycol chitosan-stearic acid copolymer. The optimized L-Psome formulation with vesicle size of 243.5±17.9 nm, PDI of 0.168±0.08 and zeta potential of (+) 27.15±0.46 mV with 25.59±0.87% AmB loading was obtained. The field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) images suggest nearly spherical morphology of L-Psome. An in vitro study showed comparatively sustained AmB release (66.082±1.73% within 24 h) and high plasma stability than commercial Ambisome® and Fungizone®, where glycol chitosan content was found to be efficient in preventing L-Psome destabilization in the presence of plasma protein. In vitro and in vivo toxicity studies revealed less toxicity of AmB-L-Psome compared to commercialized Fungizone and AmBisome favored by monomeric form of AmB within L-Psome, observed by UV-visible spectroscopy. Experimental results of in vitro (macrophage amastigote system) and in vivo (Leishmania donovani infected hamsters) illustrated the efficacy of AmB-L-Psome to augment effective antileishmanial properties supported by up-regulation of Th-1 cytokines (TNF-α, IL-12 and IFN-γ) and inducible nitric oxide synthase, and down-regulation of Th-2 cytokines (TGF- β, IL-10 and IL-4), measured by quantitative mRNA analysis by Real Time PCR (RT-PCR). Conclusively, developed L-Psome system could be viable alternative to the current less stable, toxic commercial formulations and developed as highly efficacious drug delivery system.