Abstract
Topical treatment of cutaneous leishmaniasis holds great promise for decreasing drug associated side effects and improving efficacy. This study was aimed to develop mannosylated thiolated chitosan-coated silver nanoparticles (MTCAg) loaded emulgel for the treatment of cutaneous leishmaniasis. MTC-Ag were synthesized via a chemical reduction method and were loaded into the emulgel. The nanoparticles had a zeta potential of +19.8 mV, an average particle size of 115 nm and a narrow polydispersity index of 0.26. In-vitro release profiles showed controlled release of silver ions from both the MTC-Ag and the emulgel-loaded MTC-Ag nanoparticles after 24 h. An ex-vivo retention study indicated 5 times higher retention of silver by the emulgel-loaded MTC-Ag than by the MTC-Ag nanoparticles. The in-vitro anti-leishmanial assay revealed that MTC-Ag had an excellent inhibitory effect on intracellular amastigotes, leading to ~90 % inhibition at the highest concentration tested. A 4-fold reduction in the IC
value was found for MTC-Ag compared to blank Ag nanoparticles. Cytotoxicity assay showed 83 % viability of macrophages for MTC-Ag and 30 % for Ag nanoparticles at a concentration of 80 μg/mL, demonstrating the improved biocompatibility of the polymeric nanoparticles. Drug release and retention studies corroborate the great potential of MTC-Ag-loaded emulgel for the treatment of cutaneous leishmaniasis.