Functionalization of carbon nanotubes for the drug delivery in cancer treatment

Cancer is a significant health problem and the main cause of death worldwide. Targeted drug delivery is a possible replacement for classical cancer treatment, which includes chemotherapy, surgery, and radiation therapy. With this treatment, single-walled carbon nanotubes (SWNTs) are widely exploited. They have the advantage over other materials with their conductivity, large specific surface area, and chemical stability. However, the cytotoxicity of SWNTs is still a challenge in this field. The goal of the study is to obtain biocompatible SWNTs to use in targeted drug delivery. To reduce the toxicity of SWNTs and get an excellent drug carrier, we were modified SWNTs with a novel noncovalent functionalization method: adsorption of 9-fluorenylmethyloxycarbonyl (Fmoc)-terminated aromatic amino acid-functionalized with poly(ethylene) glycol (PEG) chains onto pristine SWNTs. For that purpose, among biocompatible agents, we used a Fmoc-Cys(Trt)-OH, Fmoc-terminated aromatic amino acid, due to operational simplicity, and PEG, an FDA-approved safe polymer, with two different molecular weights (PEG5000 and PEG12000). With this work, we can say that we successfully obtained functionalized SWNTs (f-SWNTs). In addition, we determined the most competent coating among synthesized f-SWNTs in terms the stability, binding efficiency, and suspending properties. Consequently, the in-vitro effectiveness of functionalized SWNTs was tested on HEK293 cells. Our results show that modifications done improve the cytotoxicity of SWNTs, and f-SWNTs can be used in cancer drug delivery.