Thermoreversible hydrogels from RAFT-synthesized BAB triblock copolymers: steps toward biomimetic matrices for tissue regeneration.
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 gels was obtained through pulsed field gradient NMR experiments and confocal microscopy.
Kirkland
Stacey E
SE
Department of Polymer Science, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, USA.
Hensarling
Ryan M
RM
McConaughy
Shawn D
SD
Guo
Yanlin
Y
Jarrett
William L
WL
McCormick
Charles L
CL
D040761:Biomimetic Materials / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D048091:Guided Tissue Regeneration / Q000379:methods* / Q000639:trends; D006358:Hot Temperature; D020100:Hydrogels / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D023822:Tissue Engineering / Q000379:methods / Q000639:trends
D020100:Hydrogels; D011108:Polymers