Chen Long, Wu Jun, Wu Chengguang, Xing Fei, Li Lang, He Zhiyu, Peng Kun, Xiang Zhou
J Biomed Nanotechnol. 2019 Feb 1;15(2):248-260. doi: 10.1166/jbn.2019.2680.
Engraftment of tissue-engineered bone plays a pivotal role in the treatment of large bone defects. However, promoting thorough vascularization in the central area of tissue-engineered constructs remains a great challenge for clinical application. Here, we developed a three-dimensional (3D) co-culture system using biphasic calcium phosphate bioceramic (BCPB) scaffold seeded with rabbit peripheral blood-derived mesenchymal stem cells (PB-MSCs) and endothelial progenitor cells (EPCs) to improve new bone formation and vascularization for long bone segmental defects. studies, we identified morphology and characterization of PB-MSCs and EPCs. We also created a co-culture system of PB-MSCs and EPCs, and assessed the CD31 expression, gene expression of VEGF, PDGF and ALP, and tube formation ability of the co-culture system. Moreover, the biocompatibility of the BCPB was assessed and secretion levels of ALP, OC, PDGF and VEGF by co-cultured PB-MSC and EPCs in the 3D co-culture system were determined (ELISA). studies were performed to assess the ability of the cell-scaffold construct to repair a rabbit large bone defect model by X-ray examination, gross observation, and histological staining. With the extension of incubation time, both osteogenic- and vascular-related genes were up-regulated when EPCs co-cultured with PB-MSCs. In addition, BCPB is biocompatible and the expression levels of osteogenic- and vascular-related markers were also up-regulated in the 3D co-culture system. Seeding of PB-MSCs and EPCs within a modified BCPB and subsequently implanted gave rise to new bone and promoted vascularization in the rabbit model. These findings suggest that our vascularized tissue-engineered bone may be a potential alternative in the treatment of large bone defects.
组织工程骨的植入在大骨缺损治疗中起着关键作用。然而，促进组织工程构建体中心区域的充分血管化对于临床应用而言仍是一项巨大挑战。在此，我们开发了一种三维（3D）共培养系统，该系统使用接种了兔外周血来源间充质干细胞（PB-MSCs）和内皮祖细胞（EPCs）的双相磷酸钙生物陶瓷（BCPB）支架，以改善长骨节段性缺损的新骨形成和血管化。在研究中，我们鉴定了PB-MSCs和EPCs的形态及特征。我们还创建了PB-MSCs和EPCs的共培养系统，并评估了共培养系统的CD31表达、VEGF、PDGF和ALP的基因表达以及成管能力。此外，评估了BCPB的生物相容性，并通过酶联免疫吸附测定法（ELISA）测定了3D共培养系统中共培养的PB-MSC和EPCs的ALP、OC、PDGF和VEGF的分泌水平。通过X射线检查、大体观察和组织学染色进行研究，以评估细胞-支架构建体修复兔大骨缺损模型的能力。随着孵育时间的延长，当EPCs与PB-MSCs共培养时，成骨相关基因和血管相关基因均上调。此外，BCPB具有生物相容性，并且在3D共培养系统中，成骨相关标志物和血管相关标志物的表达水平也上调。在改良的BCPB内接种PB-MSCs和EPCs，随后植入兔模型中可产生新骨并促进血管化。这些发现表明，我们的血管化组织工程骨可能是治疗大骨缺损的一种潜在替代方法。
