Bilayer Polyurethane Scaffold Achieves 91.7% Diabetic Wound Closure by Day 12 via Therapeutic Release and Exudate Transport

Effective management of diabetic wounds is severely hampered by persistent infection, excessive oxidative stress, and the accumulation of viscous exudates that dilute and wash away therapeutic agents. Current wound dressings often provide passive absorption but lack active therapeutic delivery or the ability to manage complex fluid dynamics, leading to prolonged healing times and increased risk of complications. This research addresses these critical gaps by developing a spatially organized scaffold that simultaneously tackles infection, oxidative damage, and fluid management while promoting tissue regeneration.

Researchers engineered a spatially organized bilayer polyurethane scaffold designed for diabetic infected wounds. The scaffold featured a hydrophilic layer with covalently bound L-arginine and ascorbic acid for degradation-dependent nitric oxide generation and ROS scavenging. A hydrophobic layer presented REDV peptides to recruit endothelial cells. Crucially, aligned microchannels with engineered wettability gradients were integrated to enable directional transport of viscous exudates (up to 90 mPa·s). The scaffold's efficacy was evaluated in a diabetic infected wound model, measuring primary endpoints like wound closure, bacterial clearance, and inflammatory marker expression, compared against untreated controls and commercial Tegaderm dressings.

The novel bilayer polyurethane scaffold demonstrated significantly superior healing outcomes in diabetic infected wounds. By day 12, the scaffold achieved an impressive 91.7% wound closure, dramatically outperforming untreated controls (43.8%) and commercial Tegaderm dressings (56.7%). This enhanced closure was attributed to a multi-pronged therapeutic effect. The scaffold facilitated robust bacterial clearance and promoted significant inflammatory resolution, evidenced by reduced levels of pro-inflammatory cytokines TNF-α and IL-1β, alongside elevated anti-inflammatory IL-10. Furthermore, treatment led to growth factor upregulation and robust vessel maturation, critical for tissue regeneration. The engineered wettability gradients successfully managed viscous exudates, preventing therapeutic dilution.

The bilayer scaffold achieved 91.7% wound closure by day 12 in diabetic infected wounds, significantly outperforming controls (43.8%) and commercial Tegaderm (56.7%).