Objective To investigate the effect of different artificial dermal stents on the TGF -beta 1 and apoptosis in the tissue of third degree burn wounds.Methods Twelve pigs were randamized into 2 groups with 6 in each group,group A for collagen sulfonated carboxymethyl chitosan artificial dermal stent group and group B for artificial dermal stent of collagen sulfonated carboxymethyl chitosan encoded with VEGF DNA plasmid group.Three pigs from group A and group B respectively were assigned in group C with the same burn wounds on the back as in group A and B,implanted with only silicone rubber membranes.We compared the wound healing among the 3 groups,including the expression of α-SMA,TGF -β1 and apoptosis.Results The artificial dermal stent and wound healing in group B were better than those in group A and group C.During week 1 and 3,α-SMA positive vessels gradually increased in all three groups.The number of blood vessels in group C was significantly fewer than that in group A and B in 1 ~4 weeks,and the num-ber of blood vessels in group B was significantly more than that in group A in 1 ~3 weeks (P <0.05).The number of TGF -beta 1 positive signal in the 3rd week was significantly increased more than that in the first week.TGF -beta 1 positive signals were reduced in both group A and B after skin grafting.The number of TGF -beta 1 positive signal in both group A and B tended to decrease after its increase,which reached the highest in the second week.The number of positive signals of TGF -beta 1 in group C at 3 and 4 weeks was significantly more than that in group A and B (P <0.05).During 1 ~4 week,the number of apoptotic cells in the 3 groups in-creased gradually.There was no significant difference in apoptosis at different time between group A and group B (P >0.05),while the number of apoptotic cells in group C was significantly lower than that in group A or group B(P <0.05).Conclusions Artificial dermal stent of collagen sulfonated carboxymethyl chitosan encoded with VEGF DNA plasmid for III degree burn wound can promote an-giogenesis,inhibit wound contraction,promote cell apoptosis and reduce scar hyperplasia.%目的：探讨不同人工真皮支架对Ⅲ度烧伤创面修复中组织 TGF －β1和细胞凋亡的影响。方法随机将12只实验动物分成2组每组6只，A 组为胶原—磺化羧甲基壳聚糖人工真皮支架组；B 组为负载 VEGF DNA 质粒的胶原—磺化羧甲基壳聚糖人工真皮支架组。C 组为在 A、B 两组中各取3只猪，在背部制备同2组相同的烧伤创面，只植入硅橡胶膜。比较3组间创面修复情况，创面中表达α－SMA、TGF －β1的情况以及细胞凋亡数。结果B 组负载 VEGF DNA 质粒的胶原—磺化羧甲基壳聚糖人工真皮支架与创面的整合和恢复均较好于 A、C 组。1～3周3组创面α－SMA 表达阳性的血管逐渐增多。C 组在1～4周内α－SMA 表达阳性的血管数均显著少于 A、B 组（P ＜0．05）。B 组在1～3周内α－SMA 表达阳性的血管数均显著多于 A 组（P ＜0．05）。第2周3组创面 TGF －β1阳性信号数比第1周显著增多。植皮后 A、B 组创面 TGF －β1阳性信号数均有降低。A、B 两组创面 TGF －β1阳性信号数均成先上升后下降的趋势，其中2周 TGF －β1阳性信号数表达最高。C 组3、4周创面 TGF －β1阳性信号数均显著多于 A、B 组（P ＜0．05）。1～4周，3组创面的细胞凋亡数逐渐增加。在不同时一间点，A 组与 B 组的细胞凋亡数经统计学比较，均无统计学意义（P ＞0．05）。在不同时一间点，C 组的细胞凋亡数均显著少于 A、B 组（P＜0．05）。结论负载 VEGF DNA 质粒的胶原—磺化羧甲基壳聚糖人工真皮支架在Ⅲ度烧伤创中可促进血管生成，有效抑制创面收缩同时促进细胞凋亡，减少瘢痕的增生。
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