Advances in tissue engineering and regenerative medicine continue to emphasize the importance of recreating physiologically relevant mechanical environments for in vitro studies. Cellular behavior, tissue regeneration, and drug response are all significantly influenced by the viscoelasticity of the surrounding matrix. While native tissues exhibit both elastic (storage) and viscous (loss) properties, most engineered materials fail to replicate this complexity, hindering their use in predictive biological models.
Traditional biomaterials typically prioritize elasticity while neglecting the critical role of viscous damping. Moreover, these systems often suffer from uncontrolled, rapid crosslinking that eliminates opportunities for material shaping or dynamic modulation prior to final curing. Additionally, many use inert scaffolds that lack the biological cues necessary for meaningful cell interaction. These deficiencies limit the relevance of current in vitro models and slow progress in drug discovery, tissue repair, and mechanobiology.
This biomaterial platform features a dual-network hydrogel system built from hyaluronic acid derivatives designed to replicate the native viscoelasticity of biological tissues. The first network forms an elastic scaffold using photoreactive thiol-norbornene crosslinking, with tunable storage modulus controlled via UV light intensity. The second network introduces a reversible viscous component through dynamic hydrazone bonds between hydrazine and aldehyde groups. The ratio of these bonds can be adjusted for fine control of the material’s loss modulus.
Together, these networks yield a customizable, self-healing material that provides independent control over both elastic and viscous mechanical properties. Unlike conventional systems that adjust only one modulus, this approach enables true viscoelastic tuning while enhancing biocompatibility through bioactive hyaluronic acid. The ability to delay crosslinking offers processing flexibility for molding or 3D printing applications. This technology sets a new benchmark for in vitro models used in mechanobiology, stem cell research, and regenerative medicine.