负载VEGF DNA质粒人工真皮修复烧伤创面中对创面收缩与细胞凋亡的影响

目的 比较负载血管内皮生长因子(vascular endothelial growth factor,VEGF)DNA质粒胶原-磺化羧甲基壳聚糖真皮支架及胶原-磺化羧甲基壳聚糖真皮支架在修复Ⅲ度烧伤创面中对创面收缩与细胞凋亡的影响.方法 将两种不同真皮支架各移植于6头猪(共12头猪)Ⅲ度烧伤清创后创面,对植入支架1、2、3周后的创面及支架植入2周加植表皮2周的创面修复情况进行观察.同时,通过采用免疫组织化学方法,对不同时间的创面中表达α-SMA的成熟血管和肌成纤维细胞以及细胞凋亡发生情况进行检测和观察.以不植入支架的烧伤创面作为实验对照.结果 ①植入不同真皮支架的创面与无支架植人的肉芽创面不同,负载VEGF DNA质粒真皮支架修复创面效果好于无质粒负载真皮支架.②在两种不同支架植入后1～3周创面α-SMA表达阳性的血管数持续增加,支架植入2周加植表皮2周血管数比3周创面明显减少,不同时间点α - SMA表达阳性的血管以负载VEGF DNA质粒的胶原-磺化羧甲基壳聚糖人工真皮支架植入创面最多,无支架植入创面最少;③α-SMA表达阳性的肌成纤维细胞以负载VEGF DNA质粒的胶原-磺化羧甲基壳聚糖人工真皮支架植入创面最少,无支架植入创面最多,负载VEGF DNA质粒胶原-磺化羧甲基壳聚糖真皮支架及胶原-磺化羧甲基壳聚糖真皮支架创面中表达高峰为2周,无支架创面表达高峰为3周.④不同支架及无支架创面植入后2～4周,创面内细胞凋亡持续大幅增多,且无支架创面中发生细胞凋亡最少.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烧伤创面愈合过程中可促进血管化,通过抑制创面收缩和促进细胞凋亡减少瘢痕的产生.

Artificial Dermal Scaffolds Containing VEGF DNAs Improves Burn Wounds Repair through Apoptosis and Inhibition of Wound Contraction

Objective To analyze effects of collagen-sulfonated carboxymethyl chitosan porous scaffolds containing vascular endothelial growth factor(VEGF) DNAs on celluar apoptosis and wound contraction during burn wound repair.Methods Scaffold transplantations were performed for grade III burn wounds in 12 Bama miniature pigs following a 3-week wound repair observation.Epidermis of pigs were grafted at week 2 after scaffold transplantations.The treatment group was transplanted by collagen-sulfonated carboxymethyl chitosan porous scaffolds containing vascular endothelial growth factor(VEGF) DNAs and the negtivecontrol group was only with the same kind of scaffold,in addition to the blank control group without any sacfflod.Immunohistochemical staining was used to analyze α-SMA expression and apoptosis of myo-fibroblasts and mature vessels at different times.Results ① The conditions of granulation wounds transplanted by different scaffolds were different.The effect of wound repair was better in the treatment group,compared with the negative control and blank control groups.②Vessels expressing α-SMA in wounds increased continuously in 3 weeks after different transplantations,especially in the treatment group.However,treatment with epidermis graft after scaffold transplantations decreaseds the number of α-SMA-expressing vessels.③The number of myo-fibroblasts expressing α-SMA in wounds was smallest at the treatment groups,compared to other two groups.④ Celluar apoptosis was found in each group and the blank group had the lowest intensity of apoptosis.Conclusion The collagen-sulfonated carboxymethyl chitosan porous scaffold containing VEGF DNAs can effectively induce angiogenesis,and inhibit proliferation of scar through reducing wound contraction and inducing apoptosis.