Transdermal Delivery of Silk-AgNPs through Sucrose/Silk-AgNPs Antibacterial Fibroin Scaffold Packed in PEGDA Microneedles for Enhanced Wound Healing

Microenvironmental imbalance and bacterial infection are core causes of intractable chronic wounds by hindering nutrient transport and tissue repair. Herein, we innovatively fabricated a hydrophilic antibacterial scaffold based on silk fibroin (SF) and uniformly integrated it into PEGDA microneedle (MN) matrices. The composite MN system can efficiently load hydrophilic model drugs including lidocaine and rhodamine B, achieving uniform drug incorporation and improved drug-loading versatility with controllable, long-term sustained drug release behavior. Biological tests verified that the developed MN possesses excellent broad-spectrum antibacterial capacity against Staphylococcus aureus and Escherichia coli. It also exhibits favorable biocompatibility without obvious cytotoxicity and effectively promotes cell migration. In vivo experiments on full-thickness skin defect models demonstrated that the MN remarkably accelerates wound healing and optimizes healing quality. This work offers an innovative technical strategy for antibacterial drug delivery microneedles, holding great potential for clinical chronic wound treatment.