Synthesis and Characterization of Poly(ε‐caprolactone)‐ block ‐poly[ N ‐(2‐hydroxypropyl)methacrylamide] Micelles for Drug Delivery

Amphiphilic block copolymers based on HPMA and ε‐CL were synthesized by ring‐opening polymerization of ε‐CL followed by RAFT polymerization of HPMA. A copolymer composed of 34 kDa PHPMA and 8.5 kDa PCL associated into micelles with CMC of 5.4 µg · mL −1 . A novel retinoid, 3‐Cl‐AHPC‐OMe, was incorporated into micelles with 25 wt.‐% loading by dialysis method. The effective diameter of drug loading micelles was 117 nm. Incubation of micelles in PBS at 37 °C indicated 86 wt.‐% of the drug was released after 96 h. Cytotoxicity studies performed with C4‐2 prostate cancer cells showed the IC 50 dose was 1.96 µ M after 72 h of incubation, whereas the micelles without drug showed no cytotoxicity.