[An experiment study on wound healing with exogenous hyaluronic acid].

OBJECTIVE: To evaluate the effects and possible mechanisms of hyaluronic acid (HA) to inhibit scar formation as well as the dose-dependent relationship. METHODS: Forty-five health adult SD rats in a dorsal trauma model were randomly divided into the 2% HA treated-group(group A), 1% HA treated-group(group B), and the PBS treated-group as a control group(group C). The process of healing was observed, the remained wound areas were measured, and a mean wound healing time was calculated. Furthermore, the dynamic analysis was performed on local tissue protein, HPr and PCIII contents. RESULTS: 1. The remained wound areas of the control group were much smaller than that of group A and B, and the mean value of wound healing time was 15.2 +/- 2.0, 14.2 +/- 1.6 and 13.4 +/- 1.4 days respectively. 2. Histologically, when compared qualitatively with PBS controls, HA-treated wounds exhibited a less inflammatory response and angiogenesis. The fibroblast proliferated significantly, and the collagen fibril was slender and arrayed in good order, 3. The contents of tissue HPr were statistically lower in HA-treated groups, while the contents of PCIII were statistically higher compared to the control group. CONCLUSIONS: The study indicated that 1. The exogenous hyaluronan acid may effectively inhibit collagen synthesis and increase tissue PCIII content. As a result, the scar formation was decreased. 2. Hyaluronal efficacy presented a dose-dependent manner.