Development of ursolic acid-loaded polymer matrices for treatment of wounds in diabetic rats

Impaired wound healing is an important clinical problem in diabetes and results in slow wound healing which may lead to infection, sepsis, gangrene and even amputations. In the present study, polymer (collagen and arginine) based dressings were prepared to be applied as scaffolds for the control release of ursolic acid (UA), a triterpenoid that acts as an inflammatory modulator in wound healing. The activity of UA-loaded polymer matrices to treat wounds in streptozotocin diabetic induced rat was evaluated. There was a delay in wound healing in diabetic rats as compared to non-diabetic rats. The dressing exhibited potent wound healing activity as indication by the wound contraction in the excision wound model. UA-loaded polymer dressings made faster healing (21% wound area reduction) in the initial phase of wound healing in diabetic rat. The contents of hydroxyproline and hexosamine also correlated with the observed healing pattern. These findings were supported by the histopathological characteristics of healed wound sections, as greater tissue regeneration, more fibroblasts, and angiogenesis were observed in the UA-loaded polymer matrices-treated group. These results suggest that polymer-based dressings can be an effective support for UA release into diabetic wounds enhancing the healing process.