Graphical abstract Highlights • The Pluronics® P-123 and F-127 exhibited low cytotoxicity in human red cells and J774A.1 macrophages. • The viability and mitochondria membrane potential of the L. amazonensis promastigotes were not affected. • The Pluronics® P-123 and F-127 demonstrated activity against intracellular amastigotes of L. amazonensis. • The internalization of P-123 and F-127 into the parasite and macrophages was effective, and its stability was maintained. Abstract Leishmaniasis is a neglected disease and drugs approved for its treatment often lead to abandonment, failure of therapy and even death. Photodynamic therapy (PDT) has been shown to be a promising, non-invasive and selective for a target region without requiring high-cost technology. Usually, it is employed a photosensitizing agent (PS) incorporated into nanoparticles (NP). Pluronics® P-123 and F-127 micelles are very interesting aqueous NP promoting efficient and selective delivery and less adverse effects. This study aimed to detect the activity of Pluronics® P-123 and F-127 themselves since there is a scarcity of data on these NP activities without drugs incorporation. This study evaluated , in vitro , the activity of Pluronics® against promastigotes and amastigotes of Leishmania amazonensis and also their cytotoxicities. Additionally, the determination of the mitochondria membrane potential in promastigotes, internalization of these Pluronics® in the parasite membrane and macrophages and its stability in the culture medium was evaluated. Results showed that Pluronics® did not cause significant damage to human red cells and promastigotes. The P-123 and F-127 inhibited the survival rate of L. amazonensis amastigotes, and also presented loss of mitochondrial membrane potential on promastigotes. The Pluronics® showed low cytotoxic activity on J774A.1 macrophages, while only P-123 showed moderate cytotoxicity for BALB/c macrophages. The stability of P-123 and F-127 in culture medium was maintained for ten days. In conclusion, the NP studied can be used for incorporating potent leishmanicidal chemotherapy, due to their selectivity towards macrophages, being a promising system for the treatment of cutaneous leishmaniasis. [ABSTRACT FROM AUTHOR]