A platelet-rich fibrin loaded microneedle patch for pressure injury repair

A pressure injury (PI) is a chronic wound characterized by protracted healing processes and a high recurrence rate. This is primarily attributed to inadequate vascularization and aberrant extracellular matrix (ECM) remodeling. Platelet-rich fibrin (PRF)-based dressings have demonstrated certain efficacy in wound healing. Conventional dressings are unable to effectively deliver PRF to damaged deeper tissue of PI, thereby limiting its regenerative capabilities. Here, we developed PRF-loaded hyaluronic acid methacryloyl (HAMA) microneedles (PHMNs) that integrate mechanical support with targeted bioactive delivery. The PHMNs feature a uniform conical morphology, robust mechanical strength, and superior swelling capacity, enabling seamless penetration and retention within the wound. In vitro investigations demonstrate the sustained release of endogenous growth factors, significantly promoting human umbilical vein endothelial cell (HUVEC) migration, angiogenesis, and fibroblast proliferation. In a PI rat model, PHMNs significantly facilitated wound healing. On the 11th day, the wound healing rate of the PHMN group reached 98.3%, which was significantly higher than that of the other experimental groups. Immunohistochemical analysis confirms upregulated expression of vascular endothelial growth factor (VEGF) and cluster of differentiation 31 (CD31), indicating augmented angiogenesis. This study shows that PHMNs have great potential for applications in chronic wound management.