Antiparasitic Ointment Based on a Biocompatibile Carbon Dot Nanocomposite

Toward the development of emerging drugs with high efficacy, nontoxicity, and low drug resistance against Leishmaniasis, this study unravels the potential of carbon dots (CDs) and gallium-doped carbon dots (Ga@CDs). These nanoscale materials ranging in size from 4 to 7 nm prepared by ultrasonication without a catalyst were well dispersed in a commercial ointment. The formulated ointments with CDs and Ga@CDs exhibited higher activity against both Leishmania species, with a minimal concentration of 30 μg/mL for CDs/Ga@CDs, compared with a commercial counterpart. CDs were virtually nontoxic, as attested by in vitro and in vivo experimental data using mice and healthy cells. The "killing" mechanism could be attributed to the leakage of Na and K, whereas for lysosomal bursting and depolarization of mitochondria, ion leakage was ruled out. The ointments could be considered as a new class of emerging drugs to combat Leishmaniasis, a deadly disease that still infects several million people worldwide, especially in Asia and South America.