Title

Thermoreversible Hydrogels From RAFT-Synthesized BAB Triblock Copolymers: Steps Toward Biomimetic Matrices For Tissue Regeneration

Document Type

Article

Publication Date

2-1-2008

Department

Polymers and High Performance Materials

Abstract

Narrowly dispersed, temperature-responsive BAB block copolymers capable of forming physical gels under physiological conditions were synthesized via aqueous reversible addition fragmentation chain transfer (RAFT) polymerization. The use of a difunctional trithiocarbonate facilitates the two-step synthesis of BAB copolymers with symmetrical outer blocks. The outer B blocks of the triblock copolymers consist of poly(N-isopropylacrylamide) (PNIPAM) and the inner A block consists of poly(N,N-dimethylacrylamide). The copolymers form reversible physical gels above the phase transition temperature of PNIPAM at concentrations as low as 7.5 wt % copolymer. Mechanical properties similar to collagen, a naturally occurring polypeptide used as a three-dimensional in vitro cell growth scaffold, have been achieved. Herein, we report the mechanical properties of the gels as a function of solvent, polymer concentration, and inner block length. Structural information about the gets was obtained through pulsed field gradient NMR experiments and confocal microscopy.

Publication Title

Biomacromolecules

Volume

9

Issue

2

First Page

481

Last Page

486