Self-assembled Polyion Complex Micelles based on PVP-b-PAMPS and PVP-b-PDMAEMA for Drug Delivery

The double hydrophilic block copolymer, poly(N-vinylpyrrolidone)-block-poly(2-acrylamido-2-methyl-1-propanesulfonic acid), was synthesized by reversible addition-fragmentation chain transfer RAFT polymerization. Gel permeation chromatography, H-1-NMR, and FTIR were used to determine the structure and composition. In aqueous media, this block copolymer spontaneously forms polyion complex (PIC) micelles with an oppositely charged block copolymer, poly(N-vinylpyrrolidone)-block-poly(N, N-dimethylaminoethyl methacrylate). Dynamic light scattering and transmission electron micrograph showed that the micelles were <200 nm in diameter and had a narrow single distribution. The release profiles of folic acid, incorporated into the micelles, showed remarkable pH responsive behavior. The PIC micelles exhibited good biocompatibility based on MTT assay with human embryonic kidney (HEK293) cells. These PIC micelles have the potential as pH-sensitive carriers for drug delivery.