Biocompatible vesicles based on PEO-b-PMPC/alpha-cyclodextrin inclusion complexes for drug delivery

Poly(ethylene oxide) (PEO) and poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) are biocompatible polymers that have delivered clinically proven benefits in various biomedical applications. Biocompatible polymer vesicles were prepared on basis of the inclusion complexation between alpha-cyclodextrins (alpha-CDs) and double-hydrophilic poly(ethylene oxide)-b-poly(2-methacryloyloxyethyl phosphorylcholine) (PEO-b-PMPC) in aqueous media without using organic solvent. The supramolecular structure of the nano-sized vesicles was demonstrated by transmission electron microscopy (TEM), atomic force microscopy (AFM) and dynamic light scattering (DLS). The biocompatibility of PEO-b-PMPC block copolymers and PEO-b-PMPC/alpha-CDs vesicles were studied by cell viability test, and the results revealed that both of them showed excellent cytocompatibility. Hydrophilic doxorubicin (DOX center dot HCl) was successfully loaded into the vesicle with loading content of 10.3% and loading efficiency of 30%. The DOX center dot HCl loaded vesicles showed lower cytotoxicity than free drugs, and could efficiently deliver and release the drug into HepG2 cells as confirmed by fluorescence microscope (FM). With these properties, the polymer vesicles are attractive as drug carriers for pharmaceutical applications.