Liposomal formulation for topical application in photodynamic therapy against cutaneous leishmaniasis

Abstract

Cutaneous leishmaniasis (CL) is an endemic parasitic disease in northern Argentina. It does not heal spontaneously, and after prolonged and painful treatments the disease can evolve into a disfiguring and disabling form. The present work aims to obtain a liposomal formulation for topical application for photodynamic therapy (PDT) against CL. The formulation will allow the transport of methylene blue to the viable epidermis where the infected cells are located, to then activate it with light in such a way as to produce site-specific toxicity.Ultradeformable liposomes, composed of soy phosphatidylcholine and sodium cholate, loaded with methylene blue, were obtained by means of traditional methods. The suspension was characterized physicochemically by dynamic light scattering and zeta potential. Encapsulation efficiency, drug-lipid ratio, and oxygen consumption as an indicator of ROS production after photoactivation were also determined. The cytotoxicity, both intrinsic and after photoactivation, of different concentrations of the formulation was determined by MTT in the cell line HaCaT. The photoactivation was carried out with a red LED light source emitting around λ = 600 nm.In the future, the non-cytotoxic concentrations after photoactivation will be employed to assess the antiparasitic activity against promastigotes of L. braziliensis. In conclusion, it is expected to contribute with alternatives therapies against this neglected disease.