Redlich A, Perka C, Schultz O, Spitzer R, Häupl T, Burmester G R, Sittinger M
Department of Medicine/ Rheumatology, Charité, Humboldt-University, Berlin, Germany.
J Mater Sci Mater Med. 1999 Dec;10(12):767-72. doi: 10.1023/a:1008994715605.
Large bone defects caused by severe trauma, infection or tumor resection are still a major challenge for orthopaedic surgery. The key concept for successful bone regeneration consists of combining the osteoinductive effect of osteogenic cells with a suitable carrier structure to promote osteoblastic differentiation and optimal matrix production. Therefore, periosteal cells cultured in polyglycolic-polylactid acid (PGLA) fleeces were investigated for their osteogenic differentiation and used to repair critical size bone defects in a rabbit model. Periosteal cells were isolated from New Zealand White rabbits and expanded in vitro. Osteogenic differentiation was investigated by analysis of alkaline phosphatase and osteocalcin production in vitro depending on culture conditions and passage number. Cells were seeded into PGLA fleeces. After further cultivation, tissue constructs were examined histologically and by immunohistochemistry for cell distribution and osteogenic differentiation. These constructs of defined size were used to repair critical size calvarial defects (group I) in rabbits compared to a defect repair with polymers only (group II) or to untreated defects (group III). Bone healing was evaluated after 4 weeks by radiodensitometry and a special histological scoring system. For early evaluation, radiodensitometry was not sensitive enough to detect differences in calcification. However, on histologic examination the group with cell/fleece constructs revealed intense formation of uncalcified bone. The mean defect closure of the experimental group I was 65%, compared to control groups II and III with 31% and 22%, respectively. The established methods of 3-D-cell culture and ex-vivo transplant assessment proved to be a valuable tool for quality assurance. The results demonstrate that the combination of periosteal cells and polymer fleeces is a tissue engineering approach, which may have clinical applications in various fields of reconstructive surgery.
由严重创伤、感染或肿瘤切除导致的大骨缺损仍然是骨科手术面临的一项重大挑战。成功实现骨再生的关键理念是将成骨细胞的骨诱导效应与合适的载体结构相结合，以促进成骨细胞分化和最佳的基质生成。因此，研究了在聚乙醇酸-聚乳酸（PGLA）纤维中培养的骨膜细胞的成骨分化情况，并将其用于修复兔模型中的临界尺寸骨缺损。从新西兰白兔中分离出骨膜细胞并在体外进行扩增。根据培养条件和传代次数，通过分析体外碱性磷酸酶和骨钙素的产生情况来研究成骨分化。将细胞接种到PGLA纤维中。进一步培养后，对组织构建体进行组织学检查和免疫组织化学检查，以确定细胞分布和成骨分化情况。将这些确定大小的构建体用于修复兔的临界尺寸颅骨缺损（I组），并与仅用聚合物修复缺损（II组）或未处理的缺损（III组）进行比较。4周后通过骨密度测定法和一种特殊的组织学评分系统评估骨愈合情况。对于早期评估，骨密度测定法不够灵敏，无法检测到钙化差异。然而，组织学检查显示，细胞/纤维构建体组有大量未钙化骨形成。实验组I的平均缺损闭合率为65%，而对照组II和III分别为31%和22%。已建立的三维细胞培养和体外移植评估方法被证明是质量保证的一种有价值工具。结果表明，骨膜细胞与聚合物纤维的组合是一种组织工程方法，可能在重建手术的各个领域有临床应用。
