Combining soluble and bound factors in microstructured hydrogels to promote chronic wound angiogenesis and healing

PROJECT SUMMARY Soluble and bound factors play a pivotal role in cell signaling, adhesion, and function to promote wound angiogenesis and healing. Depending on the content of how these ligands are presented, they will elicit differential signaling effects. While soluble pro-angiogenic factors initiate angiogenic

responses, bound ligands modulate the duration, intensity, and specificity of these effects. Together, they coordinate vascular formation and maturation, ensuring efficient wound healing while avoiding abnormal blood vessel growth and tissue fibrosis. However, developing an integrated bioengineering system that recapitulates the complex physiological microenvironment

of wound healing with intricate balance and dynamic interactions between soluble and bound factors, remains challenging. This proposal seeks to establish an integrated bioengineering framework, harnessing the potential of advanced biomaterials design, innovative chemical processes, and state-of-art fabrication techniques to present the combination of both soluble and

bound factors to better understand how these synergized dynamic physiochemical properties govern cell signaling and modulate cell function, with a focus on chronic wound angiogenesis and healing. To achieve this goal, we aim to apply chemical routes to delineate negative charge attributes in synthetic heparin-mimetic hydrogels, and subsequently employ liquid-liquid phase

separation techniques to introduce microspheres into these pro-angiogenic materials, culminating an in vitro microfluidic wound-on-a-chip model and diabetic mouse model to investigate the cooperative effects of soluble and bound factors in cell signaling. The working hypothesis points that combining the pro-angiogenic growth factor signaling (soluble gradient) and integrin-

mediated mechanotransduction (bound factors) in phase separated 3D synthetic matrices - characterized with tunable charge densities and increased microstructures - will enhance cell-cell and cell-ECM interactions that promote cell migration, infiltration, connection, ECM deposition, and vascular network formation to induce wound angiogenesis and healing. The integration of

tunable biomaterials with a novel in vitro 3D wound injury and closure model builds a bottom-up biomimetic system to explore the synergistic effects between soluble biochemical signals and bound biophysical cues with the minimum components required for enhanced wound angiogenesis and healing. This comprehensive in vitro platform of a 3D multicellular culturing

system will identify the key matrix properties for wound healing and such insights are paramount in leading the therapeutic advancements for wound angiogenesis and chronic healing.