[A study on effect of a novel total nutritional composition for repairing full-thickness skin defects in rats]

To investigate the effects of a novel total nutritional composition on the healing of full-thickness skin defects in rats.

Ninety SPF male Wistar rats aged 8-12 weeks were randomly divided into 5 groups, with 18 rats in each group: normal group (group A), model group (group B), equal-energy standard nutrition preparation group (group C), equal-protein component group (group D), and nutritional composition group (group E). Except group A, full-thickness skin defects of 1.5 cm in diameter were established on the back of rats in the other four groups. On the basis of conventional feeding, rats received intragastric administration of sterile water or corresponding nutritional preparations twice a day for 14 consecutive days. General wound appearance was observed and wound healing rate was calculated at 0, 7, 10, and 14 days after injury. Six rats per group were sacrificed at 7, 10, and 14 days after injury to collect wound tissues. HE and Masson trichrome staining were performed to observe histopathological changes. Immunohistochemical staining was used to detect CD31-positive microvessel density.

At 7, 10, and 14 days after injury, wound healing rates in groups C, D, and E were significantly higher than those in group B, and group E was significantly higher than group D ( P<0.05). No significant difference was detected between group C and group E at all time points ( P>0.05). Histological results showed that group E had the least necrotic tissue, mildest inflammatory infiltration, richest neovascularization, widest re-epithelialization range, as well as the densest and most regularly arranged collagen deposition, with better repair effects than groups C and D. CD31 immunohistochemistry indicated that microvessel densities in groups B-E were significantly higher than that in group A ( P<0.05). Microvessel density in groups C, D, and E was significantly higher than that in group B, and groups C and E were significantly higher than group D ( P<0.05). There was no significant difference between group C and group E ( P>0.05).

The novel total nutritional composition can relieve wound inflammation, promote collagen deposition and angiogenesis, and accelerate skin wound healing. It possesses better repair efficacy than equal-protein formula, comparable therapeutic effect with equal-energy nutritional preparation, and shows obvious advantages in early wound healing.