Effects of Plasma Fibronectin on the Healing of Full-Thickness Skin Wounds in Streptozotocin-Induced Diabetic Rats

Background

Fibronectin has been shown to assist in wound healing. Impaired wound healing in diabetes mellitus is characterized by a reduction in plasma fibronectin (pFn) at the wound site. This study investigated whether topical application of pFn could improve the impaired wound healing in diabetic rats.

Materials and methods

Full-thickness skin wounds were created on the backs of streptozotocin (STZ)-induced diabetic rats. Immediately, human pFn was introduced into the wound bed, while wounds receiving human serum albumin or normal saline were used as controls. Wound closure was monitored using well-recognized wound-healing parameters: epithelialization, vascularization, collagen deposition, and migration of fibroblasts were examined histologically. Transforming growth factor (TGF)-β1 was measured by immunochemistry. Hydroxyproline levels also were assessed in the wound skin.

Results

Wound closure was significantly accelerated by local application of pFn. Furthermore, pFn-treated wounds showed increased fibroblast vascularization, collagen regeneration, and epithelialization. The numbers of infiltrating fibroblasts expressing TGF-β1 and hydroxyproline levels in pFn-treated wounds were significantly higher than those in the controls.

Conclusions

pFn can improve the impaired healing of diabetic wounds and this effect might involve an increase in the activity of fibroblasts and increased release of TGF-β1.

Key Words: wound healing, fibronectin, streptozotocin, diabetes, transforming growth factor-β1, hydroxyproline, fibroblasts, collagen