摘要
背景:骨衍生材料中冻干骨异抗原去除不充分,免疫原性强烈;脱蛋白骨和完全脱钙骨基质抗原性较弱,但前者无成骨诱导能力,后者生物力学性能很差,临床应用受到限制。目的:观察以部分脱钙冻干骨材料为支架的组织工程骨移植后兔外周血T细胞亚群的变化及移植组织的组织学变化。设计、时间及地点:随机分组设计、动物对照观察,于2006-06/2007-06在四川大学华西医院,生物治疗国家重点实验室与干细胞与组织工程研究室完成。材料:组织工程骨以兔骨膜来源的成骨细胞为种子细胞,经抗原自消化、部分脱钙、冻干后的异体骨为支架材料于体外构建。方法:将48只兔按随机数字表法分为4组,每组12只。分别用部分脱钙冻干骨、组织工程骨、自体骨、同种异体骨植入兔桡骨1cm节段性缺损处。主要观察指标:流式细胞仪检测4组植入前及植入后1,2,4周移植早期外周血T淋巴细胞亚群变化,并通过组织学检测观察植入后2,4,8,12周时4种材料的成骨作用。结果:①部分脱钙冻干骨组、组织工程骨组植入后1,2周外周血CD4+和CD8+T细胞较植入前明显升高(P<0.05)。植入后4周CD4+T细胞较植入前偏高不显著(P>0.05)。自体骨组植入后CD4+和CD8+T细胞升高不明显(P>0.05)。同种异体骨组植入后1,2,4周外周血CD4+和CD8+T细胞较植入前及其他各组同期均明显增高(P<0.05)。②组织工程骨组植入后2周与材料孔隙内有成骨细胞和成软骨细胞,可见骨及软骨混合性新生物形成,周边分布有破骨细胞,部分网架呈蚕食状被破坏吸收。植入后4周,形成的新生骨过渡为编织骨。植入后8周,形成板层骨,部分脱钙冻干骨支架材料已被完全降解﹑吸收。植入后12周,植入物均已完全被板层样骨所替代,髓腔再通。结论:部分脱钙冻干骨为支架材料构建的细胞-材料复合体移植后外周血T淋巴细胞增高,但不影响其良好的修复骨缺损能力。
BACKGROUND： Freeze-dried bone has strong immunogenicity due to insufficient removal of xenoantigen. Deproteinized bone and completely-decalcified bone have weak antigenicity, but the former has no osteoinductive property, and the latter has poor biomechanical property, so both of tern are limited in clinical application. OBJECTIVE： To observe the change of rabbit peripheral blood T lymphocyte subsets after transplantation of tissue engineered bone constituted by partially-decalcified freeze-dried bone scaffold and the histological changes of transplanted tissue. DESIGN, TIME AND SETTING： Randomized grouping, controlled animal observation, performed in the State Key Laboratory of Biotherapy （i.e. Department of Stem cells and Tissue Engineering）, Huaxi Hospital, Sichuan University between June 2006 and June 2007. MATERIALS： Tissue-engineered bone was in vitro constructed using osteoblasts, which were derived from rabbit periosteum and used as seeding cells, and xenogeneic cancellous bone, which were antigen self-digested, partially-decalcified freeze-dried bone. METHODS： Forty-eight rabbits were randomly divided into the following 4 groups, with 12 rabbits in each group： partially-decalcified freeze-dried bone group （partially-decalcified bone group）, tissue engineered bone group, autogenous bone group, and allogeneic bone group. Partially-decalcified freeze-dried bone, tissue engineered bone, autogenous bone, and allogeneic bone were respectively implanted into the 1 cm segmental defect in rabbit radius in above-mentioned groups. MAIN OUTCOME MEASURES： Prior to and I, 2, and 4 weeks after implantation, the change of rabbit peripheral blood T lymphocyte subsets were examined by flow cytometry; At 2,4,8, and 12 weeks after implantation, osteogenesis of the 4 materials was examined by routine histological examination. RESULTS： （1） In the partially-decalcified bone group, peripheral blood CD4^＋ and CD8^＋T lymphocytes were significantly increased at 1 and 2 weeks after implantation than prior to implantation （P 〈 0.05）. At 4 weeks after implantation, CD4^＋ T lymphocytes were increased, but not significantly, compared with prior to implantation （P 〉 0.05）. In the autogenous bone group CD4^＋ and CD8^＋T lymphocytes were increased, but not significantly （P 〉 0.05）. In the allogeneic bone group, CD4^＋ and CD8^＋T lymphocytes were significantly increased at weeks 1,2, and 4 after implantation than prior to implantation and the synchronic phase in the other groups （ P 〈 0.05）. （2） In the tissue engineered bone group, at week 2 after implantation, osteoblasts and chondroblasts were visible in the material porous, in addition, a new mixed tissue containing bone and cartilage formed and surrounded by osteoclasts, and partial rack was destroyed and absorbed. At week 4, newly formed bone had turned into woven bone. At week 8, lamellar bone was found, and partially-decalcified freeze-dried bone was completely degraded and absorbed. At week 12, the implant had been completely substituted by lamellar bone, and medullary cavity was recanalized. CONCLUSION： Tissue-engineered bone constituted by taking partially-decalcified freeze-dried bone as scaffold led to an increase in peripheral blood T lymphocytes, but which did not influence its good repair capability of bone defects.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2008年第36期7170-7174,共5页
Journal of Clinical Rehabilitative Tissue Engineering Research
