In vitro efficacy of polymer coated miltefosine drug against leishmania tropica.

Polymer based nanoparticles for drug delivery is an alternative approach to overcome drug resistance and drug toxicity especially for cutaneous leishmaniasis treatment. The present study shows synthesis and characterization of Miltefosine loaded chitosan nanoparticles (MFS-CNPs). The synthesized MFS-CNPs were experimented to evaluate the in vitro cytotoxicity and efficacy of the synthesized drug loaded nanoparticles by hemolysis assay and 3-(4, 5- dimethylthiazol-2-yl)-2,5-diphenyletetrazolium bromide (MTT) assay. MFS-CNPs were synthesized by ionic gelation method with sodium tripolyphosphate. The characterization of synthesized NPs was performed to observe the surface morphology, encapsulation efficacy, drug loading content, average size, and zeta potential. In vitro MTT assay was performed to calculate half maximal inhibitory concentration value of synthesized nanoparticles against promastigotes and axenic amastigotes of L. tropica. By using Scanning electron microscope, MFS-CNPs displayed spherical shape having a mean size of 70 nm along with high EE (97%), DLC (91%) and negative surface charge (- 28.0 mV). Dynamic light scattering shows the average size of NPs was 91.4 nm. Moreover, less than 5% hemolytic activity was observed in MFS-CNPs as compared to free MFS in different concentrations (100 μg/ml, 125 μg/ml, 150 μg/ml).It was observed that the effect of MFS-CNPs and free MFS on both forms of the parasite was dose and time dependent. However, the cytotoxic effects of MFS-CNPs were more salient than free MFS on both forms of L. tropica. Using MTT assay, free MFS presented low efficacy at higher concentrations (30 µg/ml) with 21.4 ± 1.3 and 20.5 ± 1.4 mean viability rate of the promastigotes and axenic amastigotes, respectively after 72 h incubation. While MFS-CNPs showed strong antileishmanial effects on both forms of L. tropica (11 ± 0.3 and 14 ± 0.8) mean viability rate after 72 h incubation at (30 µg/ml). When analyzed statistically by the software, Graph Pad Prism version 5, the IC50 value of MFS-CNPs (0.0218 ± 0.01 µg/ml) against promastigotes was effective than free MFS (0.3548 ± 0.17 µg/ml). Similarly, MFS-CNPs activity against axenic amastigotes (0.1008 ± 0.02 µg/ml) was potent than free MFS (0.5320 ± 0.21 µg/ml). Hence, MFS-CNPs exhibited significant antileishmanial activity in vitro. In conclusion, MFS-CNPs manifested enhanced in vitro Leishmanicidal and less hemolytic activity; however more studies are needed to support its efficacy in both animal and human cutaneous leishmaniasis. © Indian Society for Parasitology 2021.