Supramolecular polymers for potential biomedical applications

Abstract

The phenomena of molecular self-assembly have inspired interesting development of novel functional materials. We have been focusing on developing novel polymers with the ability to self-assemble into novel supramolecular structures, which can function as biomaterials for potential drug/gene delivery and tissue engineering applications. The key components in our macromolecular self-assembling structures include the biodegradable and biocompatible microbial biopolyesters, poly(β-hydroxyalkanoates), and the macrocyclic polysaccharides, cyclodextrins. A series of novel block copolymers and interlocked supramolecular architectures were designed and synthesized. They were characterized in terms of their molecular and supramolecular structures, as well as their properties and functions as biomaterials for potential drug and gene delivery, and tissue engineering applications. Amphiphilic block copolymers of different chain architectures composed of poly[(R)-3-hydroxybutyrate] as hydrophobic segments, and poly(ethylene glycol), poly(propylene glycol), or poly(N-isopropylacrylamide) as hydrophilic segments were synthesized. They could self-assemble to form stable micelles, nano-patterning thin films, and thermo-sensitive hydrogels, which were demonstrated to be promising potential biomaterials for controlled and sustained delivery of drugs and tissue engineering scaffolding materials. The self-assembly of block copolymers with cyclodextrins resulted in supramolecular hydrogels and cationic supramolecules, which were used as injectable drug delivery systems, and novel polymeric gene delivery vectors.