复层猪小肠黏膜下层可吸收膜的降解性能

Biodegradation properties of multi-laminated small intestinal submucosa

目的:通过体内外实验研究复层猪小肠黏膜下层(multi-laminated small intestinal submucosa,mSIS)可吸收膜的降解性能,并与应用最为广泛的Bio-Gide可吸收生物膜进行比较,为其进一步应用于临床提供实验依据。方法:体外模拟降解采用胶原酶配制降解液,对mSIS膜和Bio-Gide膜进行降解,分别于不同时间点观察二者在降解液中的形态并取出称重,计算降解率。体内皮下埋植采用9只新西兰兔,每只动物背部皮下制备6个皮囊,分别埋入mSIS膜和Bio-Gide膜。于术后4、8、12周取材,通过肉眼观察及HE染色观察不同时间二者的降解程度及组织相容性。结果:体外降解实验显示mSIS膜在第12天降解完全,而Bio-Gide膜在第7天降解完全,且mSIS在降解液中维持形状的时间更长。皮下埋植4周时,mSIS膜和Bio-Gide膜形态相对完整,镜下观二者胶原纤维连续,膜周围少许炎症细胞浸润,Bio-Gide膜部分胶原纤维与周围组织融合。术后8周,mSIS膜形态基本完整,镜下观部分区域与结缔组织融合;肉眼观Bio-Gide膜已破碎,镜下仅可见部分残留纤维与周围组织结合,无完整膜的形态。术后12周时肉眼仅见少量mSIS膜残留碎片,镜下可见mSIS膜残留纤维,与周围结缔组织基本融合;肉眼及镜下观Bio-Gide膜均已消失。结论:mSIS膜皮下埋植降解时间约为12周,Bio-Gide膜约为8周,植入体内生物相容性良好。体外降解mSIS比Bio-Gide膜降解时间延长,且空间维持能力更佳。

Objective:To study the biodegradation properties of multi-laminated small intestinal submucosa(mSIS)through in vitro and in vivo experiments,comparing with Bio-Gide,the most widely used collagen membrane in guided bone regeneration(GBR)technique,for the purpose of providing basis to investigate whether mSIS meets the requirements of GBR in dental clinics.Methods:The degradation properties were evaluated in vitro and in vivo.In vitro degradation was performed using prepared collagenase solution.Morphology of mSIS and Bio-Gide in degradation solution were observed and the degradation rate was calculated at different time points.In in vivo experiments,nine New Zealand rabbits were used for subcutaneous implantation and were divided into three groups according to observation intervals.Six unconnected subcutaneous pouches were made on the back of each animal and were embedded with mSIS and Bio-Gide respectively.At the end of weeks 4,8,and 12 after operation,gross observation and HE staining were used to evaluate the degree of degradation and histocompatibility.Results:In vitro degradation experiments showed that mSIS membrane was completely degraded at the end of 12 days,while Bio-Gide was degraded at the end of 7 days.Besides,mSIS maintained its shape for longer time in the degradation solution than Bio-Gide,indicating that mSIS possessed longer degradation time,and had better ability to maintain space than Bio-Gide.In vivo biodegradation indicated that after 4 weeks of implantation,mSIS remained intact.Microscopic observation showed that collagen fibers were continuous with a few inflammatory cells that infiltrated around the membrane.Bio-Gide was basically intact and partially adhered with the surrounding tissues.HE staining showed that collagen fibers were partly fused with surrounding tissues with a small amount of inflammatory cells that infiltrated as well.Eight weeks after operation,mSIS was still intact,and was partly integrated with connective tissues,whereas Bio-Gide membrane was mostly broken and only a few residual fibers could be found under microscope.Only a small amount of mSIS debris could be observed 12 weeks after surgery,and Bio-Gide could hardly be found by naked eye and microscopic observation at the same time.Conclusion:In vitro degradation time of mSIS is longer than that of Bio-Gide,and the space-maintenance ability of mSIS is better.The in vivo biodegradation time of subcutaneous implantation of mSIS is about 12 weeks and Bio-Gide is about 8 weeks,both of which possess good biocompatibility.