【摘要】 目的研究辐照交联法制备胶原支架的组织相容性、体内降解性以及在大鼠全层皮肤缺损创面中的修复作用。方法 I型胶原溶液使用60Co辐照交联,采用场发射环境扫描电子显微镜观察辐照交联胶原支架的多孔形貌,测量辐照交联胶原支架与戊二醛交联胶原支架的吸水率以及二者在胶原酶溶液中的降解速率。选取48只SD雄性大鼠,随机选抽取24只SD大鼠,背部分离皮下组织,形成皮下囊袋,埋植辐照交联胶原支架,常规缝合切口后1、2、3、4周取材,观察不同时间点植入部位的宏观排斥反应、支架降解程度及周围组织的外观形态,利用Image Pro软件对苏木精-伊红(HE)染色结果分析并计算剩余材料占组织面积的百分比。其余的24只SD大鼠构建大鼠背部皮肤全层缺损创面模型(每只大鼠4处创面)。左上、右上创面分别移植辐照交联胶原支架和戊二醛交联胶原支架称为实验组和对照组,左下、右下创面仅用透明的聚氨酯薄膜敷料覆盖为空白对照组,术后即刻及术后3、6 d观察创面外观,术后6 d统计创面肉芽组织的厚度以及剩余材料面积。采用t检验对组间数据进行分析、比较。结果辐照交联胶原支架孔径分布较宽,连通性良好,孔壁较薄,适合细胞长入。戊二醛交联胶原支架和辐照交联胶原支架24 h吸水率分别为(45.21±3.72)%以及(64.27±6.63)%,差异具有统计学意义(t=4.53,P<0.05)。戊二醛交联胶原支架平均降解速率为27.5%/h比辐照交联胶原支架12.5%/h降解更快。大鼠皮下埋植的辐照交联胶原支架与植入部位相容较好,HE染色显示植入部位组织炎症细胞数量较少,伴随辐照交联胶原支架降解,细胞不断迁入支架内。植入后1至4周剩余材料占组织面积的百分比分别为(43.35±5.38)%、(25.69±6.31)%、(14.55±3.50)%、(3.74±2.53)%。大鼠全层皮肤缺损修复实验,实验组植入1周时,辐照交联胶原支架已在体液作用下重新呈现出溶胀的类凝胶态,伴随降解其直径不断缩减、厚度逐渐减薄。术后同期,空白对照组伤口与实验组和对照组相比,已明显产生收缩。利用Image Pro软件分析HE染色结果显示,植入后6 d时实验组剩余材料面积(53.52±11.04)%较对照组(17.07±8.83)%多,比较差异有统计学意义(t=5.77,P<0.05),实验组肉芽组织厚度(1012.54±151.97)μm与对照组(724.52±92.87)μm、空白对照组(390.74±97.26)μm比较,差异均有统计学意义(t=10.73、24.66,P值均小于0.05)。结论辐照交联胶原支架表现出良好的组织相容性,可加速创面的愈合,促进肉芽组织的生长,降解较市售戊二醛交联胶原支架慢,有促进较大、较深伤口愈合的潜力。更多还原

【Abstract】 Objective To study the histocompatibility,degradation ability in vivo and role in repair of full-thickness skin wounds in rats of the collagen scaffolds prepared by60 Co γ-irradiation. Methods Bovine type I collagen aqueous cross-linked by radiation method,lyophilized to obtain collagen scaffold.Firstly,collagen scaffolds prepared by radiation( RCS) were observed by field emissionscanning electron microscope. Water uptake rate anddegradation rate in the collagenase solution of the two collagen scaffolds were measured. Forty-eight SD male rats were selected for animal experiment. Randomly selected 24 SD rats were separated subcutaneous on their back to form subcutaneous pouch,RCS were then embedded. The incisions were conventional sutured. After 1,2,3,4 weeks materials were drawn to observe the appearance of the implantation site of macro rejection reaction,degradation degree and the appearance of surrounding tissues. In the meanwhile,Image Pro software was used to analyzethe results of hematoxylin eosin( he)section staining and calculate the residual materials percentage. The rest of the 24 SD rats were used to build the rat-back whole layer skin defect model( 4 wounds each rat). On the upper left,upper right were implanted RSC and glutaraldehyde cross-linked collagen( GCS) and noted as experimental group and the control group. The left lower,right lowerwere covered with polyurethane film dressing as the blank control groups. Immediately after surgery and on 3th and 6th day postoperative,the appearance of the wound were observed,granulation tissue thickness and surplus material areaon the 6th day postoperative were analyzed,t test was used to analyze and compare the data between groups. Results The RCS had a wide distribution pore size,good pore connectivity,and a thin wall,which was suitable for cell growth. The 24 h water uptake rate of GCS( 45. 21 ± 3. 72) % and RSC( 64. 27 ± 6. 63) % was statistically significant( t = 4. 53,P <0. 05). The average degradation rate of GCS was 27. 5% / h,which was faster than that of RCS( 12. 5% / h).The implanted RCS in rat subcutaneously showed good compatibility,and HE staining showed that tissue inflammatory cells were few on the implantation site. Cell migration into the RCS with its degradation. After1 to 4 weeks,the percentage of material area account for tissue was( 43. 35 ± 5. 38) %,( 25. 69 ±6. 31) %,( 14. 55 ± 3. 50) %,( 3. 74 ± 2. 53) %. In the rat full-thickness skin defect repair experiments,RCS swelled into gel-like formation under humoral effect,and the diameter shrunk,thickness decreased gradually with its degraded. Compared with RCS group and GCS group,the wound blank control group had a significant contraction. Image Pro software analysis of HE staining showed that implant after 6 days,surplus material area of RCS group was( 53. 52 ± 11. 04) % which was large rcompared with the control group( 17. 07 ± 883) %,the difference has statistical significance( t = 5. 77,P < 0. 05),granulation tissue thickness of RCS group was( 1012. 54 ± 151. 97) μm which was thicker than GCS group( 724. 52 ± 92. 87)μm and blank control group( 390. 74 ± 97. 26) μm,the differences were statistically significant( t = 10. 73、24. 66,P < 0. 05). Conclusions RCS exhibited good tissue compatibility. They can also accelerate wound healing and promote growth of granulation tissue,and are slower in degradation compared with GCS. Thus,there is great potential for RCS in promoting healing of deep and large wounds.更多还原