Induced Granulation Tissue but not Artificial Dermis Enhances Early Host-Graft Interactions in Full-Thickness Burn Wounds.

Background: Cellular grafts used for skin repair require rapid integration with the host tissue to remain viable and especially to nourish the epidermal cells. Here, we evaluated the responses in the split-thickness skin grafts (STSGs) grafted on three differently treated wound beds: directly on excised wound bed (EX), on an artificial dermal template (DT) and on granulation tissue (GT) induced by cellulose sponge.
Methods: In ten burn patients, after excision, a test area was divided into three sections: One transplanted with STSG instantaneously and two sections had a pre-treatment for 2 weeks with either DT or a cellulose sponge inducing granulation tissue formation and thereafter grafted with STSGs.
Results: One week after grafting, the STSGs on GT demonstrated most endothelial CD31 ⁺ staining, largest average vessel diameters as well as most CD163 ⁺ staining of M2-like macrophages and most MIB1 ⁺ proliferating epidermal cells, suggesting an active regenerative environment. STSGs on DT had smallest vessel diameters and the least CD163 ⁺ macrophages. STSGs on EX had the least CD31 ⁺ cells and the least MIB1 ⁺ proliferating cells. After 3 months, this reactivity in STSGs had subsided, except increased dermal cell proliferation was observed in STSGs on EX.
Conclusions: Results show that pre-treatment of wound bed and induction of granulation tissue formation can accelerate host-graft interaction by stimulating graft vasculature and inducing cell proliferation.