Treatment of diabetic wounds using dissolvable microneedle patches co-delivering levofloxacin and lidocaine

Microneedle patches (MNPs) represent a minimally invasive platform for localized and painless drug delivery. In this study, we developed dissolvable MNPs co-loaded with levofloxacin and lidocaine to provide combined antibacterial and pain-relief effects for wound healing applications. The MNPs were fabricated using a biocompatible gelatin-based polymer matrix and evaluated through mechanical integrity to penetrate through the skin. In vitro zone of inhibition tests confirmed significant antibacterial activity against Escherichia coli and Staphylococcus aureus, especially for the levofloxacin/lidocaine dual-drug formulation. The pain-relief activity was assessed using a pinch test in diabetic mice, where lidocaine-containing MNPs produced a marked reduction in pain sensitivity compared to blank controls. Furthermore, full-thickness skin wounds in diabetic mice treated with the levofloxacin/lidocaine-loaded MNPs showed accelerated wound-healing over 5 days, as verified by wound-closure measurement and histological H&E staining. The enhanced healing response was attributed to the additive effect of the antibiotic and analgesic agents, resulting in reduced bacterial burden and inflammation, and improved tissue regeneration. These findings suggest that gelatin-based levofloxacin/lidocaine-loaded MNPs offer a promising therapeutic strategy for managing painful skin-wounds under diabetic conditions through localized, sustained, and patient-convenient drug delivery.