Enhancement of curcumin antitumor efficacy and further photothermal ablation of tumor growth by single-walled carbon nanotubes delivery system in vivo

Curcumin, a commonly used natural product for antitumor therapy, is unable to achieve full potential due to poor bioavailability. Based on our previous report of a novel delivery system for curcumin using functionalized single-walled carbon nanotubes by phosphatidylcholine and polyvinylpyrrolidone (SWCNT-Cur), we further evaluated SWCNT-Cur's performance in vivo and characteristics in vitro. SWCNT-Cur significantly increased the blood concentration of curcumin, up to 18-fold, in mice. And in a murine S180 tumor model, SWCNT-Cur exhibited significantly higher inhibition efficacy on tumor growth and no obvious toxicity in main organs. Moreover, photothermal therapy induced by SWCNT under near-infrared radiation further facilitated SWCNT-Cur to inhibit the tumor growth in vivo. In addition, solvent residue is negligible in SWCNT-Cur formulation, and hydrogen bonding was formed between void carriers and curcumin, as demonstrated by GC chromatograph and IR spectra. Furthermore, experiments of confocal microscopy and spectrofluorometer showed that SWCNT-Cur gave a six-fold higher uptake for curcumin compared to native curcumin in human prostate cancer PC-3 cells. In conclusion, curcumin delivery with functionalized SWCNT is a promising strategy to enhance anticancer activity in vivo by enhancing cell uptake and blood concentration, changing physicochemical properties of curcumin and combining phototherapeutic with chemotherapeutic effects.