Development of Photocurable NorHA-dECM Hybrid Hydrogels to Study Cell-Matrix Interactions

Biomimetic culture platforms aid in understanding cell behavior in vitro and are useful for studying mechanisms of disease progression and tissue regeneration. Synthetic hydrogels are widely used for this purpose, but while they offer advantages such as tunability and mechanical stability, they lack the range of biochemical signals present in the native microenvironment. On the other hand, decellularized extracellular matrices (dECMs) retain native biochemical signals but their adoption as stable in vitro culture platforms is limited due to batch variability, poor mechanical stability, and limited tunability. Here we report the development of hybrid hydrogels comprising dECM and a photocurable norbornene-modified hyaluronic acid (NorHA) polymer. To overcome structural heterogeneity of dECM that inhibits its solubility, uniform gelation, and spatial uniformity during cell culture, we physically process dECM by grinding, shearing, or both, prior to incorporation within NorHA. Both processing methods reduce microscale dECM aggregation and improve physical gelation at 37 °C. The addition of dECM up to 10 mg/mL within NorHA hydrogels neither affects rapid UV cross-linking nor compromises mechanical properties, as evaluated using oscillatory shear rheology and uniaxial compression testing. Both processes significantly improve the uniform distribution of dECM within 3D hybrid hydrogels, as evaluated by staining hydrogel cryosections. Fibroblasts show significantly higher spreading area and proliferation on hybrid hydrogels compared with control NorHA hydrogels. Taken together, photocurable hybrid hydrogels having uniformly distributed dECM combine the biochemical complexity of native dECM with the tunability of a synthetic polymer and represent an advance in the engineering of biomimetic platforms to investigate cell-matrix interactions.