Recombinant human collagen microneedle patches loaded with PRP for diabetic wound treatment.

Chronic nonhealing wounds represent significant complications of diabetes, bearing a substantial burden and posing risks of disability or mortality. In diabetic wounds, continuous tissue fluid exudation, inflammatory cell migration, fibrosis, and bacterial biofilm formation create a "barrier", which decreases the treating efficacy of therapeutics. To address these limitations, a recombinant human collagen type III microneedle patch (rhCol III-PRP^M) loaded with platelet-rich plasma (PRP) was developed, in which methacrylated rhCol III (rhCol III-MA) loaded with PRP was utilized to form needle tips, while rhCol III-MA formed the base part of the patch. RhCol III-PRP^M featured adequate mechanical qualities, swelling capacity, and sustained in vitro release of growth factors from the activation of PRP for over 7 days. Leveraging the synergistic effects of rhCol III and PRP, rhCol III-PRP^M patches facilitated cell proliferation, migration, and angiogenesis, and reduced oxidative stress. In animal experiments, this microneedle patch effectively promoted the healing of diabetic wounds during a 20-day treatment, partially due to upregulating integrins and phosphorylated ERK protein levels. Diverging from other microneedle strategies, the rhCol III exhibited "dual functionality," serving as both the microneedle patch matrix and therapeutic agent, promoting wound healing upon patch dissolution while delivering PRP. The combination of rhCol III and PRP in the form of a microneedle patch offered a straightforward and efficacious way for effective diabetic wound management, and showed promise in bringing new possibilities in clinical practice.