Nanodiamond-conjugated transferrin as chemotherapeutic drug delivery

Abstract Targeted therapy is considered to be a promising strategy of cancer treatments. Herein we demonstrate the potential of a nanotechnology strategy for special drug delivery based on nanodiamond (ND) functionalized by transferrin. Specifically, the transferrin–doxorubicin (Tf–DOX) complex is covalently coupled with carboxylated ND to prepare the targeted nanomedicine (ND-(Tf–DOX)). In vitro studies showed that ND-(Tf–DOX) can effectively deliver the drug inside living cells via a clathrin-dependent and transferrin receptor-mediate endocytosis pathway by flow cytometry analysis, and the ND-(Tf–DOX) nanomedicine located in the lysosomes through laser scanning confocal microscopy. In vivo , we found that tumor volume change of tumor-bearing mice treated with ND-(Tf–DOX) nanomedicine was lightly lower than that of DOX-treated. The results demonstrated that the targeting capability of ND-(Tf–DOX) nanomedicine relative drug alone is not significant, and it may be disturbed by proteins when they are placed in a complex biological environment. However, it can markedly decrease side effects compared to DOX alone in both the liver and spleen. This suggests that in vivo ND-(Tf–DOX) nanomedicine can effectively inhibit tumor growth as the same as DOX. More importantly, it can decrease side effects. This study attempts to endowed transferrin-functionalized and chemotherapeutic drug-loaded nanodiamond as a platform for drug delivery and therapy to cancer cells.