Use of autologous tissue engineered skin to treat porcine full-thickness skin defects / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To explore a feasible method to repair full-thickness skin defects utilizing tissue engineered techniques.</p><p><b>METHODS</b>The Changfeng hybrid swines were used and the skin specimens were cut from the posterior limb girdle region, from which the keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA, and type II collagenase. The cells were seeded in Petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with trypsin to separate them from the floor of the tissue culture dishes. A biodegradable material, Pluronic F-127, was prefabricated and mixed with these cells, and then the cell-Pluronic compounds were seeded evenly into a polyglycolic acid (PGA). Then the constructs were replanted to the autologous animals to repair the full-thickness skin defects. Histology and immunohistochemistry of the neotissue were observed in 1, 2, 4, and 8 postoperative weeks.</p><p><b>RESULTS</b>The cell-Pluronic F-127-PGA compounds repaired autologous full-thickness skin defects 1 week after implantation. Histologically, the tissue engineered skin was similar to the normal skin with stratified epidermis overlying a moderately thick collageneous dermis. Three of the structural proteins in the epidermal basement membrane zone, type IV collagen, laminin, and type VII collagen were detected using immunohistochemical methods.</p><p><b>CONCLUSIONS</b>By studying the histology and immunohistochemistry of the neotissue, the bioengineered skin graft holds great promise for improving healing of the skin defects.</p>

Effects of hVEGF cDNA on random skin flap via a replication-deficient adenovirus vector / 中华整形外科杂志

<p><b>OBJECTIVE</b>The purpose of this study was to determine the effects of local delivery of vascular endothelial growth factor( VEGF) transferred with adenovirus-mediated gene on the survival of ischemic random skin flap in rats.</p><p><b>METHODS</b>The animals were divided into three groups randomly (n = 10) . A 2 cm x 8 cm dorsal skin flap was designed with the pedicle at the level of the iliac crest. In group A (AdCMV-VEGF), each animal received 10(12) PR replication-deficient recombinant adenovirus (AdCMV-VEGF) in the distal two-thirds of the proposed flap by means of the subdermal injection at ten different locations. In group B (AdCMV-GaI), each received 1012 PR AdCMV-Gal. In Group C (Saline), each received 1 ml saline. Three days after the treatment, the flap was elevated as planed way and re-sutured back to its donor site. All the animals were evaluated 7 days after the operation.</p><p><b>RESULTS</b>The mean percentage of surviving flap area was (85.91 +/- 2.54)% in group A, (59.56 +/- l.18)% in group B, and (61.48 +/- l.09)% in group C. There was a significant increase in the percentage of the survival area in the flaps of the group A, compared with the group B and group C (Group B vs. Group A, P < 0.01; Group C vs.Group A, P < 0.01, Group B vs. Group C, P >0.05). Hybridization in the situ, the immunohistochemical stain showed that the VEGF was expressed in the survival tissue of the flap treated with the AdCMV-VEGF, but it was not found in the control groups. Histological analysis demonstrated qualitatively greater amount of granulation tissue and angiogenesis was found in the group treated with the AdCMV-VEGF than the controls.</p><p><b>CONCLUSIONS</b>The results may indicate that Ad vector carrying VEGF cDNA could be useful in enhancing the survival of the skin flap due to the effect of the local delivery of the VEGF.</p>

Effect of adenovirus-mediated gene transfection of vascular endothelial growth factor on survival of random flaps in rats / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the effect of local application of vascular endothelial growth factor (VEGF) via adenovirus-mediated gene transfer on survival of full thickness flaps selected randomly in rats.</p><p><b>METHODS</b>Thirty Sprague-Dawley rats weighing 480-520 g were used in this study. A dorsal flap (8 cm x 2 cm) in full thickness with the pedicle located at the level of the iliac crest was designed. Then the rats received 1,012 pfu replication-deficient recombinant adenovirus carrying VEGF (AdCMV-VEGF group, n=10), 1,012 pfu recombinant beta-galactosidase adenovirus (AdCMV-Gal group, n=10) and 1 ml saline (saline group, n=10), respectively, in the distal two thirds of the proposed flap by means of subdermal injection at 8 different locations. Three days after treatment, the flaps were elevated as originally designed and sutured back in situ. The survival rate of the flaps was evaluated on day 7 after operation.</p><p><b>RESULTS</b>The survival rate of the flaps in the AdCMV-VEGF group increased significantly as compared with those of the AdCMV-Gal group (P<0.01) and the saline group (P<0.01). Immunohistochemical staining showed that VEGF was expressed in the survival flaps injected with AdCMV-VEGF. Histological analysis showed that more granulation tissues and angiogenesis were observed in the AdCMV-VEGF group than those in the AdCMV-Gal and the saline groups.</p><p><b>CONCLUSIONS</b>Local application of adenovirus-mediated VEGF165 cDNA may efficiently improve the survival of ischemic skin flaps.</p>