(247e) Patterning Neovascularization Using Hybrid Granular Hydrogel Scaffolds and Microsurgery

In reconstructive surgery, hydrogel scaffolds are often used to enable the repair and regeneration of soft tissue loss by providing a niche for revascularization. However, slow and random vascularization limits the efficacy of this technique, resulting in suboptimal repair or treatment failure. In response to this challenge, we developed a novel approach to hasten and pattern microvascular network formation in hydrogel scaffolds based on combining a surgical micropuncture (MP) technique with gelatin methacryloyl (GelMA) granular hydrogel scaffolds (GHS) that have tailored interstitial void space architectures. We conducted the MP by perforating rats hindlimb artery and vein using a microneedle, followed by implanting the GHS with varying pore architectures. The in vivo results show that the MP accelerates neovascularization and GHS guides the vascular pattern based on the void spaces among microgels. Together, GHS scaffolds and MP significantly promoted vascular network formation compared with bulk hydrogel scaffolds and/or non-MP controls. Overall, hybrid MP-GHS approach provides unprecedented opportunities for rapid and patterned neovascularization, opening new opportunities in translational reconstructive surgery.