(145e) Dynamically Responsive Living Acellular Nanocomposite Hydrogels

The extracellular matrix (ECM) in mammalian tissues exhibits unique mechanical properties such as shear stiffening and cell-mediated self-healing, which are critical for regulating cellular behavior and tissue function. Inspired by these dynamic properties, we present a bio-inspired nanocomposite hydrogel system—termed LivGels—that mimics key features of native ECMs using acellular, biopolymer-based materials. Our design incorporates a bifunctional nanoparticle linker (nLinker) consisting of rigid cellulose nanocrystals grafted with semi-flexible, aldehyde- and carboxylate-modified cellulose chains. These anisotropic linkers facilitate the formation of physically and chemically crosslinked hydrogel networks through ionic interactions and dynamic covalent hydrazone bonds. The resulting LivGels have tunable nonlinear mechanical behavior, including shear stiffening within a biologically relevant stiffness range, as well as autonomous self-healing. This biomimetic platform demonstrates how hierarchical design using natural polymers and nanoparticles can replicate the adaptive mechanics of living tissues, offering new opportunities in the development of smart, responsive soft materials.