Synthesis and Evaluation of Thiolated Emulgel based Silver Nanoparticles for Cutaneous Leishmaniasis

Abstract

Worldwide cases of Leishmaniasis are reported from every continent except Antarctica with a death toll of 50,000 annually. Available conventional treatment options for Leishmaniasis are reported with emerged resistance, high toxicity profile and limited access to intra-macrophage parasite reservoir. Our aim was to develop an alternative treatment modality to overcome the targeting, efficacy and safety issues of traditional treatment regimens for cutaneous Leishmaniasis. Mannosylated thiolated silver (MTC-Ag) nanoparticles loaded emulgel was successfully synthesized and characterized for physicochemical properties and anti-Leishmanial potential. To overcome the stability problems of silver nanoparticles, thiomer stabilized silver nanoparticles were prepared. Mannosylated thiolated chitosan (MTC) coated silver nanoparticles (MTC-Ag) were synthesized by chemical reduction method with zeta potential +19.8 ± 2.5 , size 170.0nm ± 5.6 and PDI 0.16 ± 0.2. In-vitro release profile showed controlled release of silver ions both from MTC-Ag nanoparticles and MTC-Ag nanoparticles loaded emulgel over 24 hours. Ex-vivo retention study exhibited 5 times greater retention of silver for MTC-Ag loaded emulgel than MTC-Ag nanoparticles. In-vitro anti-Leishmanial assay indicated 4-folds reduction of IC50 values for MTC-Ag nanoparticles as compared to Ag nanoparticles. Biocompatibility results showed 83% ± 5% viability of macrophages for MTC-Ag nanoparticles and 30% ± 5% for Ag nanoparticles at concentration of 80μg/ml. Based on above mentioned results, it is evident that the newly synthesized MTC-Ag loaded emulgel is a potential candidate for the treatment cutaneous Leishmaniasis. Keywords: Silver nanoparticles, Mannose receptors, MTC-Ag nanoparticles, Leishmaniasis, Emulgel