Intradermal injection of autologous dermal fibroblasts improves wound healing in irradiated skin

Background. Despite its well-recognized benefits in the management of sever al solid tumors, the use of radiotherapy prior to surgery is associated wit h a high incidence of significant surgical wound healing complications. Rad iation-induced damage to dermal fibroblasts has been proposed as an importa nt cause. We hypothesized that the introduction of normal, unirradiated fib roblasts into previously irradiated skin would enhance healing of the subse quent surgical wound. Materials and methods. Four groups of wounds were examined in female Wistar rats: (1) unirradiated skin (n = 10), (2) irradiated skin injected with ti ssue culture medium alone (n = 17), (3) irradiated skin injected with autol ogous dermal fibroblasts (n = 17), and (4) irradiated skin injected with ir radiated autologous dermal fibroblasts (n = 7). Wounds were evaluated biome chanically and histologically. Results. The biomechanical values of breaking load, ultimate tensile streng th, elastic modulus, and toughness were significantly greater in the irradi ated wounds injected with fibroblasts than those injected with medium only. These cell-injected wounds did not perform as well biomechanically as thos e in unirradiated skin. Irradiating the cells prior to injection resulted i n biomechanical results no better than those in medium-injected wounds. Conclusions. These results demonstrate that injection of normal, unirradiat ed fibroblasts significantly improves healing of the irradiated surgical wo und. These cells are likely better able to respond to the proliferative, mi gratory, and synthetic demands of the wound healing environment, as injecti on of irradiated cells has an equivalent effect on healing as injection of medium alone. (C) 1999 Academic Press.