【摘要】 目的:观察聚左消旋聚乳酸膜对羊腭部软组织缺损的引导修复作用。方法:实验于2004-03/07在四川大学华西基础医学院动物实验中心完成。选取四川简阳山羊12只,分为左消旋聚乳酸组和空白对照组,6只/组。左消旋聚乳酸膜由成都迪康中科生物医学材料有限公司制备,分子质量约4.1×104u,拉伸强度>5.0M Pa,厚0.5m m,膜无色透明,可以根据需要修剪成不同的形状。于两组羊硬腭中份切除一18.0m m×16.0m m的矩形黏骨膜,暴露骨面,用骨膜分离器潜行分离周围黏骨膜,形成约3m m的游离黏骨膜边缘。再于暴露骨面用牙科裂钻做一17.0m m×15.0mm的矩形骨缺损,使得口鼻腔相通,形成腭部贯通性缺损模型。左消旋聚乳酸组植入一21.0m m×19.0m m左消旋聚乳酸膜,空白对照组制备同样大小的软硬组织缺损,但不植入左消旋聚乳酸膜。分别于术后1～7周对两组腭部软组织缺损大小进行测量。7周后取左消旋聚乳酸组缺损区新生软组织标本,行组织切片光镜观察。结果:实验纳入12只羊,全部进入结果分析。①两组术后不同时间平均黏骨膜缺损面积的比较:与空白对照组比较,左消旋聚乳酸组于术后第3,4,5,6周均显著缩小[(249.11±26.08),(202.32±14.15)m m2;(249.11±28.34),(167.32±22.73)m m2;(249.11±27.23),(72.14±12.08)mm2;(249.11±26.78),(3.34±2.28)m m2;P均<0.01],且于第7周完全关闭软组织缺损。②两组大体观察结果比较:左消旋聚乳酸组:术后第1周,术区有轻微红肿,缺损边缘已有新生的黏膜上皮组织,黏膜缺损面积因水肿的边缘而轻微的缩小,左消旋聚乳酸膜由透明变为乳白色半透明。第2周,红肿已消失,黏骨膜缺损边缘新生的上皮组织已经完全覆盖黏膜缺损边缘,黏膜缺损面积进一步缩小,左消旋聚乳酸膜仍为乳白色半透明。第3～5周时,黏膜缺损面积持续缩小,左消旋聚乳酸膜变为乳白色不透明。第6周时,6只山羊的黏膜缺损已有5只完全关闭,愈合的软组织中央均有不同大小的疤痕组织形成。剩下的1只在第7周时完全关闭。空白对照组:第1周,术区未见红肿,黏膜上皮组织再生尚未完全覆盖黏膜缺损边缘。第2周,黏膜上皮组织已完全覆盖黏膜缺损边缘。第3周,黏骨膜向鼻腔垂直生长,覆盖部分骨缺损边缘,水平测量黏骨膜缺损及骨缺损面积没有缩小。第4～7周,黏骨膜缺损及骨缺损与第3周时没有变化。6只羊均形成永久性口鼻瘘。③左消旋聚乳酸组光镜观察结果:新生黏膜组织由复层鳞状上皮覆盖。较薄的新生黏膜组织处,上皮和结缔组织纤维排列方向较为紊乱;较厚的新生黏膜组织处,纤维排列方向成横向或纵向走行,在不同的层面走向不同,但在同一层面排列较为整齐。结缔组织内可观察到少量血管,未见神经、肌肉和骨组织。愈合软组织中央均可见大小不等的瘢痕组织。新生黏膜与材料接触处可见不规则致密结缔组织形成的包膜,未见明显炎症反应和异物反应。结论:左消旋聚乳酸膜可引导羊腭部黏骨膜沿其生长,自行修复一定大小的软组织缺损从而达到修复重建腭部软组织缺损的目的。更多还原

【Abstract】 AIM: To evaluate the role of PDLLA biofilm as guide to regeneration of the soft tissue defects in the palates of goats. METHODS: The experiment was done in the Animal Experiment Center of West China Basic Medical College, Sichuan University, during March to July 2004. Twelve goats as experimental animals were divided into PDLLA experimental group and blank control group at random. PDLLA biofilms (molecular weight, 4.1×104 D stress strength, > 5.0 MPa 0.5 mm in thickness colorless and transparent) were supplied by Dikang Biomedical Co., Ltd. 18.0 mm×16.0 mm rectangle mucoperiosteum and 17.0 mm×15.0 mm bone were removed in mid part of the hard palates. The oral and nasal cavity were communicated each other and the perforating model of palate defect was established. 21.0 mm×19.0 mm PDLLA biofilms were implanted into the defects of the experimental group. The same size defect was established in the blank control group, but no biofilms were implanted. The soft tissue defects of two groups were measured 1-7 weeks after the operation. The regenerating soft tissue in the defects was observed histologically 7 weeks after the operation. RESULTS: All the 12 goats in the experiment were brought into the result analysis. ①The defect area comparison between the two groups at different time: Compared with the blank control group, the defect area of PDLLA experimental group significantly decreased in 3,4,5,6 weeks(249.11±26.08),(202.32±14.15);(249.11±28.34),(167.32±22.73);(249.11±27.23),(72.14±12.08);(249.11±26.78),(3.34±2.28)mm2, P < 0.01, and the mucoperiosteal defects were closed in 7 weeks. ②The comparison of general observation: In the PDLLA experimental group, the operating area was red and swelling in the 1st week, but the abnormal disappeared in the 2nd week. The defect area decreased slightly and the biofilms became chalky and semitransparent in 1 and 2 weeks. The defect area decreased continuously in 3, 4, 5 weeks, and the biofilms became chalky and opacity. In the 6th week, the mucoperiosteal defects were completely closed in 5 of all the 6 goats, and the defect was closed in the left goat in the 7th week. The scar tissue could be observed in the regenerating tissue. In the blank control group, the operating area was not red and swelling in the 1st week. The epithelium regenerated and completely covered the edge of defect in the 2nd week. The mucoperiosteum regenerated into nasal cavity and covered the edge of bone defect. The defect area did not decrease in 3, 4, 5, 6, 7 weeks. The permanent fistula between oral cavity and nasal cavity occurred in all the 6 goats.③The light microscope observation: The regenerating tissue was covered with multilayer squamous epithelium and the deferent size scar tissue could be observed. The fibers of epithelium and connective tissue were irregular in the thin regenerating tissue and regular in deferent layers of the thick regenerating tissue. The blood vessel could be observed in the connective tissue, and no nerve, muscle or bone was observed. The irregular envelope of tight connective tissue formed around the biofilms. No obvious inflammation and foreign body reaction were observed.CONCLUSION: PDLLA biofilm can guide the regeneration of mucoperiosteal tissue to close the limited size palatal defects, and to reconstruct the palate soft tissue.更多还原