title: Thermoreversible hydrogels from RAFT-synthesized BAB triblock copolymers: steps toward biomimetic matrices for tissue regeneration.
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 gels was obtained through pulsed field gradient NMR experiments and confocal microscopy.
authors.affiliation: Department of Polymer Science, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, USA.
authors.forename: Stacey E
authors.initials: SE
authors.lastname: Kirkland
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Hensarling
authors.forename: Shawn D
authors.initials: SD
authors.lastname: McConaughy
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Guo
authors.forename: William L
authors.initials: WL
authors.lastname: Jarrett
authors.forename: Charles L
authors.initials: CL
authors.lastname: McCormick
mesh_terms: 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
chemical_list: D020100:Hydrogels; D011108:Polymers