COMPARISON OF PIG AND GUINEA-PIG FULL AND PARTIAL THICKNESS SKIN EXCISION WOUND MODELS FOR EVALUATING THE EFFECTS OF RHPDGF-BB

Pig and guinea pig full and partial thickness wounds were compared for their suitability for evaluating the wound healing effects of recombi nant human platelet-derived growth factor-BE (rhPDGF-BB). In these fou r models, rhPDGF-BB (at 100 mu g/ml) consistently resulted in a dramat ic increase in the amount of granulation tissue compared with vehicle controls. The effects of rhPDGF-BB on contraction and epithelializatio n, however, were more variable, partly depending : on the model and ve hicle. While rhPDGF-BB had no effect on contraction in pig full thickn ess wounds, it dramatically inhibited contraction in guinea pig full t hickness wounds, presumably because the granulation tissue arising fro m these wide, shallow wounds acted as a splint to inhibit contraction. In both the pig and guinea pig full thickness excision models, as the wounds became epithelialized, the amount of rhPDGF-BB-induced granula tion tissue rapidly returned to control levels. The pig full thickness excision model was suitable for placement of various sponge matrices, but none of the matrices enhanced the filling of the wounds, making t he determination of rhPDGF-BB's effects on granulation tissue more dif ficult to assess. In conclusion, although there were differences in so me of the wound healing parameters measured, we found that either pig or guinea pig full thickness wounds are suitable for evaluating rhPDGF -BB's effects on wound healing.