Potent in vitro antileishmanial activity of a nanoformulation of cisplatin with carbon nanotubes against Leishmania major

Abstract Objectives The aim of this study was to evaluate the cytotoxicity and antileishmanial activity of cisplatin-bonded carbon nanotubes both against promastigotes and amastigotes of Leishmania major in vitro . Methods Cisplatin-bonded single-walled carbon nanotubes (CP-SWCNT) and cisplatin-bonded multi-walled carbon nanotubes (CP-MWCNT) were considered as test compounds. In addition, SWCNT, MWCNT, free cisplatin and meglumine antimoniate (Glucantime ® ) were considered as controls. The effect of each compound was evaluated both on promastigote and amastigote stages of L. major and the results were compared. Results There was a statistically significant difference between the half-maximal inhibitory concentration (IC 50 ) of CP-SWCNT and each of the controls, including SWCNT, cisplatin and Glucantime ® ( P   0.05). In addition, IC 50 values of CP-MWCNT and each of the controls, including MWCNT, cisplatin and Glucantime ® , were significantly different both for promastigotes and amastigotes ( P   0.05). However, the selectivity index (SI) of CP-SWCNT was ® (16.28) were >10, indicating the selective effect of these two compounds on the parasite. Moreover, the IC 50 of CP-MWCNT (0.11 ± 0.09 μM) for amastigotes was 41-fold lower than that of Glucantime ® (4.52 ± 1.31 μM), suggesting that a lower dose of CP-MWCNT in comparison with Glucantime ® is required to kill 50% of amastigotes. Conclusions According to the potent in vitro antileishmanial activity of CP-MWCNT at low concentration against L . major , we suggest that they are evaluated in an animal model.