Department of Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Tanta University, Tanta, Egypt.
J Dent Res. 2022 Feb;101(2):166-176. doi: 10.1177/00220345211037247. Epub 2021 Sep 11.
The clinical translation of bone tissue engineering for reconstructing large bone defects has not advanced without hurdles. The bioreactor (IVB) concept may therefore bridge between bone tissue engineering and reconstructive surgery by employing the patient body for prefabricating new prevascularized tissues. Ideally, IVB should minimize the need for exogenous growth factors/cells. Periosteal tissues are promising for IVB approaches to prefabricate tissue-engineered bone (TEB) flaps. However, the significance of preserving the periosteal vascular supply has not been adequately investigated. This study assessed muscle IVB with and without periosteal/pericranial grafts and flaps for prefabricating TEB flaps to reconstruct mandibular defects in sheep. The sheep ( = 14) were allocated into 4 groups: muscle IVB (M group; = 3), muscle + periosteal graft (MP group; = 4), muscle + periosteal flap (MVP group; = 4), and control group ( = 3). In the first surgery, alloplastic bone blocks were implanted in the brachiocephalic muscle (M) with a periosteal graft (MP) or with a vascularized periosteal flap (MVP). After 9 wk, the prefabricated TEB flaps were transplanted to reconstruct a mandibular angle defect. In the control group, the defects were reconstructed by non-prevascularized bone blocks. Computed tomography (CT) scans were performed after 13 wk and after 23 wk at termination, followed by micro-CT (µCT) and histological analyses. Both CT and µCT analysis revealed enhanced new bone formation and decreased residual biomaterial volume in the MVP group compared with control and MP groups, while the M group showed less new bone formation and more residual biomaterial. The histological analysis showed that most of the newly formed bone emerged from defect edges, but larger areas of new bone islands were found in MP and MVP groups. The MVP group showed enhanced vascularization and higher biomaterial remodeling rates. The periosteal flaps boosted the reconstructive potential of the prefabricated TEB flaps. The regenerative potential of the periosteum was manifested after the transplantation into the mechanically stimulated bony defect microenvironment.
用于重建大骨缺损的骨组织工程的临床转化并非没有障碍。因此，生物反应器（IVB）概念可以通过利用患者身体预制新的预血管化组织来在骨组织工程和重建外科之间架起桥梁。理想情况下，IVB 应尽量减少对外源性生长因子/细胞的需求。骨膜组织对于预制组织工程骨（TEB）皮瓣的 IVB 方法具有很大的潜力。但是，保留骨膜血管供应的重要性尚未得到充分研究。本研究评估了有和没有骨膜/颅骨皮瓣的肌肉 IVB 用于预制 TEB 皮瓣以重建绵羊下颌骨缺损。将绵羊（= 14）分为 4 组：肌肉 IVB（M 组；= 3），肌肉+骨膜移植物（MP 组；= 4），肌肉+骨膜皮瓣（MVP 组；= 4）和对照组（= 3）。在第一次手术中，将同种异体骨块植入肱头肌（M）中，带有骨膜移植物（MP）或带血管化骨膜皮瓣（MVP）。9 周后，将预制的 TEB 皮瓣移植以重建下颌角缺损。在对照组中，通过非预血管化的骨块来重建缺损。在 13 周和结束时的 23 周后进行计算机断层扫描（CT）扫描，然后进行微 CT（µCT）和组织学分析。CT 和 µCT 分析均显示 MVP 组与对照组和 MP 组相比，新骨形成增加，残留生物材料体积减少，而 M 组新骨形成较少，残留生物材料较多。组织学分析表明，大多数新形成的骨头来自于缺损边缘，但在 MP 和 MVP 组中发现了更大的新骨岛区域。MVP 组显示出增强的血管化和更高的生物材料重塑率。骨膜皮瓣增强了预制 TEB 皮瓣的重建潜力。骨膜的再生潜力在移植到机械刺激的骨缺损微环境中后表现出来。
