Photochemical properties and activity of water-soluble polymer/c(60) nanohybrids for photodynamic therapy

Water-soluble star-like poly(vinyl alcohol)/C(60) and poly{[poly(ethylene glycol) acrylate]-co-(vinyl acetate)}/C(60) nanohybrids are prepared by grafting macroradicals onto C(60) and are assessed as photosensitizers for photodynamic therapy. The photophysical and biological properties of both nanohybrids highlight key characteristics influencing their overall efficiency. The macromolecular structure (linear/graft) and nature (presence/absence of hydroxyl groups) of the polymeric arms respectively impact the photodynamic activity and the stealthiness of the nanohybrids. The advantages of both nanohybrids are encountered in a third one, poly[(N-vinylpyrrolidone)-co-(vinyl acetate)]/C(60) , which has linear grafts without hydroxyl groups, and shows a better photodynamic activity.