Hydrogel compositions for direct-write printing applications

摘要

A thermo-responsive shear-thinning photo-curable composition comprises water, a linear amphiphilic polyether ABA triblock copolymer comprising at least one pendent ene group (*—CH═CH₂) capable of undergoing a thiol-ene reaction, a water-soluble crosslinking agent comprising two or more methylenethiol groups (*—CH₂SH), and a photoinitiator. Under non-shear conditions and a triblock copolymer concentration suitable for direct-write printing, the composition is a viscoelastic solid (hydrogel) at a temperature of about 15° C. to about 45° C., and is a free-flowing liquid (sol) between 0° C. and about 10° C. The hydrogel form can be shear-thinned at about 15° C. to about 45° C. to form a sol suitable for a direct-write printer using an extruding print-head. The compositions covalently crosslink when flood-exposed to ultraviolet radiation. The compositions have utility in forming three-dimensional scaffolds for growing living cells.