Enzyme‐Assisted Activation Technique for Producing Versatile Hydrogel Microparticle Scaffolds with High Surface Chemical Reactivity

Abstract

Advancing the integration of nonliving and living components relies heavily on functional hydrogel materials with biocompatibility and customizability. In this study, an enzyme‐assisted surface activation method is developed to produce reactive hydrogel microparticles (HMPs) comprising thiolated hyaluronic acid and hyperbranched poly(β‐hydrazide esters). Fluorescence labeling analysis reveals an over six‐fold increase in surface‐active functional group density on the hydrogels and three‐fold on HMPs after enzyme activation. This enhancement improves accessibility of active elements, facilitating post‐functionalization and optimizing their capacity to support initial cell adhesion and spreading as carriers for cell cultures. Additionally, by utilizing the exposed reactive double bonds on the HMP surfaces post‐enzymatic treatment, thiolated HMPs are produced through a thiol‐ene coupling reaction with thiolated polymers. These thiolated HMPs bond together spontaneously, resulting in the formation of annealed granular hydrogels with interconnected large‐pore networks and a tunable storage modulus (G’) from tens to hundreds of pascals, compatible with most soft tissues. Integrated with 3D bioprinting, this hydrogel ink generates prints that foster cell adhesion, migration, growth, and network formation. Moving forward, integrating various granular hydrogel scaffold systems with the enzyme‐assisted activation technique holds significant promise for enhancing performance and expanding applications in regenerative medicine and innovative living materials.