Enzyme-Triggered Formation of Tensegrity Structures for Mechanospatial Manipulation of Hydrogels

Hydrogels with spatially programmable mechanical properties hold great potential for use in biomedical applications. Inspired by the architecture of the cytoskeleton, we present a strategy for constructing tensegrity-structured hydrogels (TS-Gels) through enzyme-triggered crystal growth to enable precise mechanospatial manipulation. Specifically, alkaline phosphatase (ALP) was covalently anchored to a polyacrylamide (PAAm) hydrogel matrix to catalyze the in situ dephosphorylation of phosphotyrosine precursors, leading to the formation of rigid tyrosine crystals. These crystals functioned as compressive sticks, establishing tensegrity structures within the hydrogel network. By tuning the crystallization kinetics, both the structural morphology and mechanical reinforcement could be precisely controlled. The resulting TS-Gels exhibited significantly enhanced local tensile strength and stiffness, allowing for spatial-mechanical patterning via photo-initiated printing, mold-assisted shaping, and laser engraving. Furthermore, the unique mechanospatial tunability of TS-Gels was demonstrated in tribological surface engineering, underscoring their potential for use in tissue engineering and responsive biomaterials.