Uptake enhancement of curcumin encapsulated into phosphatidylcholine-shielding micelles by cancer cells

Internalization of drugs by cancer cells is a crucial factor to impact cancer treatment effect. Curcumin, having inhibitory effect on a variety of cancers, was encapsulated into micelles of six-arm star-shape poly(ε-caprolactone)-b-poly(2-methacryloyloxyethylphosphorylcholine) (6sPCL-PMPC) in order to enhance its concentration in blood and cellular uptake. Micelles and curcumin-loaded micelles were prepared by the solvent-evaporation method. Drug-loading content and drug-loading efficiency could be achieved as high as 18.9 and 98%. MTT results showed that these curcumin-loaded micelles displayed significant cell cytotoxicity, while these blank micelles were noncytotoxic. The curcumin-loaded 6sPCL-PMPC micelles showed higher efficiency to kill HeLa cells than that of curcumin-loaded PCL-PEG micelles. The cellular uptake study indicated that the curcumin encapsulated into 6sPCL-PMPC micelles was ingested more by HeLa cells than the curcumin encapsulated into PCL-PEG micelles. In conclusion, the micelles with phosphatidylcholine (PC) groups as their exterior can greatly enhance the uptake by HeLa cells and the cytotoxicity of curcumin due to excellent internalization by cancer cells.