观察重组人Ⅲ型胶原蛋白水凝胶用于治疗猪全层皮肤缺损创面，在创面愈合和血管新生，新生真皮胶原排列状态和胶原比例等方面的影响。

将重组人Ⅲ型胶原蛋白粉末与海藻酸钠粉末以质量比10∶1混合，溶于无菌磷酸盐缓冲液中，制备成胶原蛋白含量为10%的溶液，使用时以10% Ca^2＋溶液交联成凝胶状。以巴马小型猪作为实验动物制备动物模型，在每头猪背部正中线两侧旁开2 cm分别用手术刀制备3个边长5 cm深达肌肉筋膜的正方形全层皮肤缺损创面，采用同体自身对照，实验组用重组人Ⅲ型胶原蛋白水凝胶治疗，水凝胶外层覆盖无菌硅胶膜保湿；阳性对照组用可吸收性敷料治疗；阴性对照组仅用无菌硅胶膜覆盖。术后7、14、21、90 d，进行创面大体观察，并取材行苏木精-伊红染色，光学显微镜下观察创面修复情况、炎症反应，免疫组织化学染色法检测创面CD31的表达并计数新生血管数目，天狼猩红饱和苦味酸染色偏振光观察胶原纤维排列、Ⅲ型胶原蛋白比例。实验数据比较采用单因素方差分析、SNK-q检验或Kruskal Wallis H检验。

实验组创面肉芽组织平整，颜色鲜红，柔软湿润。光学显微镜下见实验组较阴性对照组组织炎症反应轻微，创面修复早期肉芽组织生长速度快。CD31免疫组织化学染色结果显示，术后7、14、21 d，实验组新生毛细血管数分别为(18.8±2.7)、(32.0±4.4)、(42.8±4.5)个/ hpf，而阴性对照组仅分别为(12.0±3.0)、(16.6±2.3)、(12.6±4.1)个/ hpf，各个时间点实验组新生毛细血管数均高于阴性对照组，差异均有统计学意义(P值均小于0.05)。术后14、21、90 d创面新生真皮组织天狼猩红饱和苦味酸染色结果显示，实验组较阴性对照组胶原纤维排列规整，与阳性对照组相似，而Ⅲ型胶原蛋白比例较阴性和阳性对照组均升高。

重组人Ⅲ型胶原蛋白水凝胶可促进全层创面愈合和血管新生，促进新生真皮组织胶原纤维有序排列，增加Ⅲ型胶原在新生真皮胶原中所占比例，从而改善创面愈合质量，并有望减轻创面愈合后的瘢痕形成。

To observe the effect of recombinant human type-Ⅲ collagen hydrogels on wound healing and vascularization, collagen fiber arrangement, and type-Ⅲ collagen proportion during pig full-thickness skin defect wound healing.

The recombinant human type-Ⅲ collagen powder was mixed with sodium alginate powder in mass ratio 10: 1 and dissolved in aseptic phosphate buffer saline to prepare a solution of 10% collagen content. 10% Ca²⁺ solution was used to crosslink the above mixed solution to form gelatin when used.Bama miniature male pigs (n=3) were used as experimental animal to prepare animal models. In each pig, three square-shaped full-thickness skin defect wounds were made on both sides of the back. Each pig served as its own control. Tissues in the experimental group were treated with recombinant human type-Ⅲ collagen hydrogel and covered with sterile silicone membranes for moisturizing. Positive control tissues were treated with absorbable dressing, and negative control tissues were covered with sterile silicone membranes only. On postoperative days 7, 14, 21, and 90, wounds were grossly observed and specimens collected to assess wound repair and inflammatory responses using hematoxylin-eosin staining under a microscope. CD31 expression and regenerated blood vessel counts were measured immunohistochemically. The collagen fiber arrangement and type-Ⅲ collagen proportion were observed using picrosirius red staining under a polarized light microscope. The experimental data were compared by one-way ANOVA, SNK-q test or Kruskal Wallis H test.

Granulation tissues in the experimental group were smooth, bright red, soft, and moist. Inflammatory responses were reduced and early granulation tissue growth rate was elevated in the experimental group compared to those in the control groups. On postoperative days 7, 14 and 21, CD31 expression revealed that the number of new capillaries in the experimental group was (18.8±2.7), (32.0±4.4) and (42.8±4.5)/hpf respectively, while that in the negative control group was (12.0±3.0), (16.6±2.3) and (12.6±4.1)/hpf, respectively. The number of new capillaries in the experimental group was higher than that in the negative control group at each time point. The differences were statistically significant (with P values below 0.05). The collagen fibers in the experimental group exhibited better arrangement than those in the negative control group, and comparable to the positive control group. Moreover, a higher type-Ⅲ collagen proportion was found in the experimental group than in the positive and negative control groups at 14, 21 and 90 days after surgery according to picrosirius red staining.

Recombinant human type-Ⅲ collagen hydrogel promotes wound healing, induces angiogenesis, promotes collagen fiber better arrangement in regenerated dermal tissues, and increases the type-Ⅲ collagen proportion in regenerated dermal tissues during the process of wound healing. These benefits could improve wound healing and may reduce scar formation after wound healing.