Thermosensitive Micelles Based on Folate-Conjugated Poly(N-vinylcaprolactam)-block-Poly(ethylene glycol) for Tumor-Targeted Drug Delivery

Thermosensitive PNVCL-b-PEG block copolymer coupled with folic acid was prepared as an anti-cancer drug carrier. This polymer self-assembled into stable micelles in aqueous solutions at above 33 degrees C. At 37 degrees C, the release profile of PNVCL-b-PEG-FA micelles showed a slower andmore controlled release of the entrapped 5-FU than that at 25 degrees C. The blank and 5-FU-loaded PNVCL-b-PEG-FA micelles did not induce remarkable cytotoxicity against the EA.hy 926 human endothelial cell line; however, 5-FUloaded PNVCL-b-PEG-FA micelles showed a cytotoxicity effect against 4T1 mouse mammary carcinoma cells due to the availability of loaded anti-cancer drugs delivered to the inside of the cancer cells by the folate-receptor-mediated endocytosis process.