Vascularization of Lando® dermal scaffold in an acute full-thickness skin-defect porcine model.

The Lando® dermal scaffold is a newly developed, tissue-engineered dermal scaffold material. This study sought to observe its vascularization in an acute full-thickness skin-defect porcine model. There were eight Tibetan pigs in this research. Six 5 × 5 cm full-thickness skin-defect wounds were prepared on the dorsal area of each pig, which were divided into two groups. The experimental group wounds were covered by Lando® dermal scaffolds, while the other received Vaseline gauzes as blank control. At day 3, 7, 14 and 21 after injury, the general condition of wounds was observed, and wound specimens were obtained for HE staining, Masson staining and the expression of CD31, α-SMA and VEGF, which were examined by immunohistochemistry. The results showed the wounds in the experimental group (Lando) were drier with a lower incidence of infection, and the granulation tissues grew better and smoother than the control group. In the experimental group, the hyperemia, edema and inflammatory reactions were milder, the fibroblasts ingrew earlier, the capillaries grew mostly parallel to the wound surface which resembled normal skin, and the collagen fibers were thicker with more regular arrangement than in the control group. The CD31 + microvessel count, α-SMA + microvessel count and VEGF expression of the experimental group were significantly higher than the control group at day 7 and 14 after injury (p < .05). In conclusion, the Lando® dermal scaffold showed good vascularization at day 14 post grafting in an acute full-thickness skin-defect porcine model, which may be associated with increased expression of VEGF.