NIR initiated and pH sensitive single-wall carbon nanotubes for doxorubicin intracellular delivery

Abstract

In this work, we synthesized a pH sensitive poly(ethylene glycol)–doxorubicin (PEG–DOX) on single-wall carbon nanotubes (SWNTs). Using multimodal nonlinear optical imaging microscopy, we found that low power (1 mW cm⁻²) near-infrared radiation can initiate prodrug burst release from the carbon nanotubes in seconds. The successful SWNTs capping with PEG–DOX (denoted PEG–DOX@SWNT) was determined by transmission electron microscopy and FTIR results. The in vitro release of DOX from the PEG–DOX@SWNT was evaluated upon changes of pH values and NIR treating time. The cytotoxicity of the PEG–DOX@SWNT was also evaluated. This dual-sensitive delivery system based on SWNTs provides a facile approach to promote drug release and kill cancer cells.