Bioinspired 3D Printing of Functional Materials by Harnessing Enzyme-Induced Biomineralization

Nature builds structurally ordered and environmentally adaptive composite materials by harnessing biologically catalyzed mineralization under mild conditions. Despite recent advancements in engineering conventional materials with microorganisms through biomimetic mineralization, it remains difficult to produce mineralized composites that integrate the hierarchical structure and living attributes of their natural counterparts. Here, a kind of functional material is developed by integrating 3D printed hydrogel architectures with enzyme-induced biomineralization. It is shown that the enzyme-induced mineralization intensely transforms flexible and soft hydrogels (modulus of 125 kPa) to rigid (150 MPa) and highly mineralized hydrogel composites. Coupling with embedded 3D printing, sophisticated and mineralized free-form architectures are fabricated in the absence of sacrificial inks, which were previously unattainable through conventional manufacturing strategies. Moreover, by exploiting multi-material 3D printing to tailor the construct composition, exquisite control over the mineral distribution within the hydrogel constructs can be achieved, thus composite materials with tessellated architectures and unconventional mechanics could be obtained. The study provides a viable means to fabricate composite materials with high-fidelity architectures and tailored mechanical properties, unlocking paths to the next generation of functional materials and structures by integrating 3D printing with biomineralization.