An insight into the role of nanotechnology in photothermal and photodynamic therapy of leishmaniasis.

Leishmaniasis, a neglected tropical disease caused by Leishmania parasites, affects >12 million people globally. Conventional chemotherapy is plagued by drug resistance, systemic toxicity and high cost, creating an urgent need for novel therapeutic strategies. Photothermal therapy and photodynamic therapy with or without synergistic pharmacotherapy have emerged as highly promising alternatives, especially useful in drug-resistant cutaneous leishmaniasis. These methods rely on localized hyperthermia and/or reactive oxygen species (ROS) generated by nanoparticles under light to selectively eradicate the thermosensitive parasites. This review critically examines recent advances in photoactive nanoparticle-based therapy of leishmaniasis. We discuss the intrinsic efficacy of photothermal agents and photosynthesizers such as gold and graphene oxide nanoparticles. Furthermore, we highlight the evolution of the field toward sophisticated, next-generation strategies designed to enhance specificity and efficacy. These include the antibody-targeted delivery of nanoparticles to infected macrophages and the development of combinatorial nanoplatforms that synergize photothermal ablation or photodynamically generated ROS, with controlled drug release, enabling a multimodal attack.