Green and direct functionalization of poly (ethylene glycol) grafted polymers onto single walled carbon nanotubes: Effective nanocarrier for doxorubicin delivery

Abstract This paper reports a green and direct functionalization of poly(ethylene glycol)-graft-[furfuryl-graft-(poly(styrene-alt-maleic anhydride))] (PEG-PSMF) on the surface of single walled carbon nanotubes (SWCNTs) in aqueous media through Diels-Alder (DA) click reaction. Firstly, novel PEG grafted, furfuryl functionalized copolymers were prepared by RAFT polymerization followed by ring opening reactions. The functional copolymer was simply grafted on SWCNTs by DA reaction at room temperature under ultrasonication. The resulting hybrid materials were characterized by 1H NMR, GPC, UV–vis, FT-IR, TGA, TEM, and DLS. The hybrid materials possessed a high drug loading capacity (DLC) of doxorubicin (DOX), which could reach up to 279.9 wt.% of DLC. Moreover, in vitro drug release profiles showed that drug release rate at pH 5.5 under an acidic condition of tumor cell microenvironment was much higher than at pH 7.4 of the physiological condition. MTT assays demonstrated that the hybrid materials did not have any practical cytotoxicity against the normal HEK293 cell line, while drug loaded hybrids displayed a high antitumor activity towards HeLa cancer cells. This strategy offers a promising SWCNT-based drug carrier for tumor-targeted chemotherapy.