Zhao Jun, Zhang Zhiyuan, Wang Shaoyi, Sun Xiaojuan, Zhang Xiuli, Chen Jake, Kaplan David L, Jiang Xinquan
Department of Oral and Maxillofacial Surgery, College of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, China.
Bone. 2009 Sep;45(3):517-27. doi: 10.1016/j.bone.2009.05.026. Epub 2009 Jun 6.
Tissue engineering has become a new approach for repairing bony defects. Highly porous osteoconductive scaffolds perform the important role for the success of bone regeneration. By biomimetic strategy, apatite-coated porous biomaterial based on silk fibroin scaffolds (SS) might provide an enhanced osteogenic environment for bone-related outcomes. To assess the effects of apatite-coated silk fibroin (mSS) biomaterials for bone healing as a tissue engineered bony scaffold, we explored a tissue engineered bony graft using mSS seeded with osteogenically induced autologous bone marrow stromal cells (bMSCs) to repair inferior mandibular border defects in a canine model. The results were compared with those treated with bMSCs/SS constructs, mSS alone, SS alone, autologous mandibular grafts and untreated blank defects. According to radiographic and histological examination, new bone formation was observed from 4 weeks post-operation, and the defect site was completely repaired after 12 months for the bMSCs/mSS group. In the bMSCs/SS group, new bone formation was observed with more residual silk scaffold remaining at the center of the defect compared with the bMSCs/mSS group. The engineered bone with bMSCs/mSS achieved satisfactory bone mineral densities (BMD) at 12 months post-operation close to those of normal mandible (p>0.05). The quantities of newly formed bone area for the bMSCs/mSS group was higher than the bMSCs/SS group (p<0.01), but no significant differences were found when compared with the autograft group (p>0.05). In contrast, bony defects remained in the center with undegraded silk fibroin scaffold and fibrous connective tissue, and new bone only formed at the periphery in the groups treated with mSS or SS alone. The results suggested that apatite-coated silk fibroin scaffolds combined with bMSCs could be successfully used to repair mandibular critical size border defects and the premineralization of these porous silk fibroin protein scaffolds provided an increased osteoconductive environment for bMSCs to regenerate sufficient new bone tissue.
组织工程已成为修复骨缺损的一种新方法。具有高度孔隙率的骨传导支架对骨再生的成功起着重要作用。通过仿生策略,基于丝素蛋白支架(SS)的磷灰石涂层多孔生物材料可能为骨相关结果提供增强的成骨环境。为了评估磷灰石涂层丝素蛋白(mSS)生物材料作为组织工程骨支架对骨愈合的影响,我们探索了一种组织工程骨移植物,该移植物使用接种了经成骨诱导的自体骨髓基质细胞(bMSCs)的mSS来修复犬模型中的下颌骨下缘缺损。将结果与用bMSCs/SS构建体、单独的mSS、单独的SS、自体下颌骨移植物和未治疗的空白缺损治疗的结果进行比较。根据影像学和组织学检查,bMSCs/mSS组术后4周观察到新骨形成,12个月后缺损部位完全修复。在bMSCs/SS组中,与bMSCs/mSS组相比,观察到新骨形成,缺损中心残留更多的丝支架。bMSCs/mSS构建的工程骨在术后12个月达到了令人满意的骨矿物质密度(BMD),接近正常下颌骨(p>0.05)。bMSCs/mSS组新形成的骨面积数量高于bMSCs/SS组(p<0.01),但与自体移植组相比无显著差异(p>0.05)。相反,在单独用mSS或SS治疗的组中,骨缺损仍留在中心,伴有未降解的丝素蛋白支架和纤维结缔组织,新骨仅在周边形成。结果表明,磷灰石涂层丝素蛋白支架与bMSCs联合可成功用于修复下颌骨临界尺寸边缘缺损,这些多孔丝素蛋白支架的预矿化作用为bMSCs再生足够的新骨组织提供了增强的骨传导环境。