Cross-linked micelles prepared from amphiphilic copolymers having active ester groups

Abstract

Poly(pentafluorophenyl methacrylate) (PPFPMA) was first subjected to post-polymerization modification with oligo(ethylene glycol) methyl ether amine (OEG-NH2) and yielded poly(pentafluorophenyl methacrylate)-co-poly(oligo(ethylene glycol methacrylamide)), PPFPMA-co-POEGMAM. These amphiphilic random copolymers can self-assemble into micellar nanoparticles in water having size less than 100 nm. By tandemly reacting the pentafluorophenyl (PFP) groups in the copolymeric nanoparticles with a dithiol crosslinker, cystamine, redox-responsive nanogels can be formed. The remaining PFP groups in the nanogels were removed by reacting with isopropylamine, resulting in a crosslinked drug delivery nano-carriers with highly biocompatible property. All stepwise post functionalization was monitored by FTIR and 19F NMR spectroscopy. Release of a hydrophobic guest molecules, nile red (NR) or curcumin (CUR) from the nanogels, simultaneously encapsulated during micelles formation, can be accelerated in the presence of glutathione (GSH). Results from cytocompatibility evaluation and cellular uptake study suggested that these developed redox-responsive nanogels strongly possessed a potential for applications in controlled delivery.