A wound healing model using healing-impaired diabetic mice.

A quantitative histological approach was employed to evaluate the effects of basic fibroblast growth factor (bFGF) in healing-impaired diabetic mice. The dorsal areas of female mutant diabetic mice, C57BL KsJ db/db (Jackson Lab.), were given two 6 mm-size full thickness wounds with a punch biopsy instrument. After application of bFGF, the wounds were left open. 8 days after wounding, the mice were sacrificed, and histological sections were evaluated using several histological parameters, such as the degree of wound closure, granulation tissue thickness, matrix density, and capillary numbers. Application of 5 micrograms of bFGF for 5 days induced significant responses by all of these dermal parameters when compared to those of non-treated db/db mice (p < 0.001). A minimum of 0.5 micrograms bFGF per day was required for a significant effect. Time-course experiments indicated that the granulation response in bFGF-treated mice peaked between 8 and 12 days and decreased after 12 days, while matrix density continued to increase until the 18th day.