Mechano-Responsive Hydrogels Crosslinked by Block Copolymer Micelles.

Block copolymer micelles (BCMs) were prepared from amphiphilic diblock copolymers of poly(n-butyl acrylate) and poly(acrylic acid) partially modified with 2-hydroxyethyl acrylate. Radical polymerization of acrylamide in the presence of micellar crosslinkers gave rise to elastomeric hydrogels (BCM-PAAm) whose mechanical properties can be tuned by varying the BCM composition. Transmission electron microscopy (TEM) imaging revealed stretch-induced, reversible micelle deformation in BCM-PAAm gels. A model hydrophobic drug, pyrene, loaded into the micelle core prior to the formation of BCM-PAAm gels, was dynamically released in response to externally applied mechanical forces. The BCM-crosslinked hydrogels with combined strength and force-modulated drug release are attractive candidates for the repair and regeneration of mechanically-active tissues.