Thermosensitive hydrogels based on polypeptides for localized and sustained delivery of anticancer drugs

Thermosensitive hydrogels based on poly(gamma-ethyl-L-glutamate)-poly(ethylene glycol)-poly(gamma-ethyl-L-glutamate) triblock copolymers (PELG-PEG-PELG) were prepared for localized and sustained delivery of anticancer drugs. The polypeptide-based hydrogels showed much lower critical gelation concentration than the traditional polyester-based hydrogels. In vivo biocompatibility studies revealed that the in situ formed gels in the subcutaneous layer last for similar to 21 days, and H&E staining study suggested acceptable biocompatibility of our materials in vivo. Then the hydrogels were tried as injectable implants to encapsulate antitumor drug, paclitaxel (PTX), to assess the in situ anti-tumoral activity using liver cancer xenograft model. The results demonstrated that the PTX-incorporated hydrogels could efficiently suppress the tumor growth, and did not result in obvious damage to normal organs. Therefore, the polypeptide-based thermosensitive hydrogels designed in the present study have great potential to serve as an effective platform for localized anti-cancer drug delivery. (C) 2013 Elsevier Ltd. All rights reserved.