Sensitizing nanoparticle based platinum(IV) drugs by curcumin for better chemotherapy.

A polymer-cisplatin(IV) conjugate was prepared by attaching Pt(IV)-COOH to a biodegradable amphiphilic block copolymer containing pendant OH groups. The conjugate can assemble into micelles (M(Pt)) with a mean diameter of ca. 169nm. Further, curcumin (CM) was used to sensitize platinum drug based nanoparticles to overcome cisplatin resistance and enhance antitumor efficacy. In vitro studies showed that M(Pt)/CM combinations had great synergistic effect both on cisplatin sensitive and cisplatin resistant cell lines (A2780 and A2780DDP). In vivo studies showed that M(Pt)/CM had a much lower systemic toxicity and an enhanced antitumor efficacy compared to cisplatin alone or the corresponding cisplatin/CM combinations. Therefore, polymer-cisplatin(IV) conjugate with small molecules that serve as a non-cytotoxic or minimally cytotoxic sensitizer or enhancer provide a promising strategy, which may have potential clinical implications in the near future.