Electrosprayed hydrogel microsphere dressing promotes vascularization and accelerates wound healing.

Repair of skin injuries is often hindered by the challenge of neovascularization, particularly in severely damaged wounds that struggle to self-heal, potentially leading to organ dysfunction or even death. Thus, promoting vascularization is crucial for effective skin repair. This study employed electrostatic spraying to fabricate methacrylated hyaluronic acid (HAMA) hydrogel microspheres for encapsulation of ectodermal mesenchymal stem cells (EMSCs), and optimization of the process parameters to assess their biocompatibility. Under in vitro conditions, EMSCs microspheres were successfully induced to differentiate into structures with vascular networks. Additionally, the optimal modification ratio of dopamine-modified hyaluronic acid (HADA) was determined to enhance the adhesive and mechanical properties of the dressing. Based on these findings, a dressing incorporating cell microspheres and adhesive hydrogels was developed. This dressing demonstrated formation of microvascular structures in vitro. Upon in vivo transplantation, it integrated tightly with surrounding tissues, modulated the inflammatory response, and accelerated wound healing in mouse model. This composite dressing, integrating cell-laden microspheres within a hydrogel's framework, offers a simple and effective approach to promote skin microvascular. STATEMENT OF SIGNIFICANCE: This study describes a hydrogel dressing that uses electrostatically sprayed methacrylated hyaluronic acid (HAMA) microspheres to encapsulate ectodermal mesenchymal stem cells (EMSCs). The hydrogel composition was optimized using dopamine-modified hyaluronic acid (HADA), which improved adhesion, while methacrylated polyvinyl alcohol (PVAMA) enhanced mechanical strength. This highly effective, low-risk hydrogel dressing promoted angiogenesis and accelerated wound healing. The results of this study highlight the potential of hydrogel dressing for clinical applications in tissue engineering and regenerative medicine, thus providing a promising strategy for the treatment of severe skin injuries.