1Departments of Surgery and of Biomedicine, University Hospital Basel, CH-4031 Basel, Switzerland.
Eur Cell Mater. 2010 Mar 3;19:127-35. doi: 10.22203/ecm.v019a13.
Grafts generated by cultivation of progenitor cells from the stromal vascular fraction of human adipose tissue have been proven to have osteogenic and vasculogenic properties in vivo. However, in vitro manufacture of such implants is challenged by complex, impractical and expensive processes, and requires implantation in a separate surgery. This study investigates the feasibility of an intraoperative approach to engineer cell-based bone grafts with tissue harvest, cell isolation, cell seeding onto a scaffold and subsequent implantation within a few hours. Freshly isolated adipose tissue cells from a total of 11 donors, containing variable fractions of mesenchymal and endothelial progenitors, were embedded at different densities in a fibrin hydrogel, which was wrapped around bone substitute materials based on beta-tricalcium phosphate (ChronOS), hydroxyapatite (Engipore), or acellular xenograft (Bio-Oss). The resulting constructs, generated within 3 hours from biopsy harvest, were immediately implanted ectopically in nude mice and analysed after eight weeks. All explants contained blood vessels formed by human endothelial cells, functionally connected to the recipient's vasculature. Human origin cells were also found within osteoid structures, positively immunostained for bone sialoprotein and osteocalcin. However, even with the highest loaded cell densities, no frank bone tissue was detected, independently of the material used. These results provide a proof-of-principle that an intraoperative engineering of autologous cell-based vasculogenic bone substitutes is feasible, but highlight that - in the absence of in vitro commitment--additional cues (e.g., low dose of osteogenic factors or orthotopic environmental conditions) are likely needed to support complete osteoblastic cell differentiation and bone tissue generation.
从人脂肪组织的基质血管部分培养的祖细胞产生的移植物已被证明在体内具有成骨和血管生成特性。然而，这种植入物的体外制造受到复杂、不切实际和昂贵的过程的挑战，并且需要在单独的手术中植入。本研究调查了在术中制造基于细胞的骨移植物的可行性，方法是在数小时内进行组织采集、细胞分离、将细胞接种到支架上，然后进行植入。从总共 11 名供体中新鲜分离的脂肪组织细胞，含有不同比例的间充质和内皮祖细胞，以不同的密度嵌入纤维蛋白水凝胶中，该水凝胶包裹在基于β-磷酸三钙（ChronOS）、羟磷灰石（Engipore）或无细胞异种移植物（Bio-Oss）的骨替代材料周围。从活检采集后 3 小时内生成的这些构建体立即异位植入裸鼠体内，并在 8 周后进行分析。所有外植体都包含由人内皮细胞形成的血管，这些血管与受体的脉管系统功能相连。在类骨质结构中也发现了人类起源的细胞，这些细胞对骨涎蛋白和骨钙素呈免疫阳性染色。然而，即使使用最高负载的细胞密度，也没有检测到真正的骨组织，与使用的材料无关。这些结果提供了一个原理证明，即术中工程自体细胞血管生成骨替代物是可行的，但强调指出，在没有体外承诺的情况下，可能需要额外的线索（例如，低剂量的成骨因子或原位环境条件）来支持完全成骨细胞分化和骨组织生成。
