Department of Chemical Engineering, School of Engineering and Technology, Hampton University, Hampton, VA, USA.
Center for Orthopaedic Research, Innovation and Training, McGovern Medical School, UTHealth, Houston, TX, USA.
Sci Rep. 2021 Nov 18;11(1):22509. doi: 10.1038/s41598-021-02070-z.
Recent advances in materials and manufacturing processes have allowed the fabrication of intricate implant surfaces to facilitate bony attachment. However, refinement and evaluation of these new design strategies are hindered by the cost and complications of animal studies, particularly during early iterations in the development process. To address this problem, we have previously constructed and validated an ex-vivo bone bioreactor culture system that can maintain the viability of bone samples for an extended period ex-vivo. In this study, we investigated the mineralization of a titanium wire mesh scaffold under both static and dynamic culturing using our ex vivo bioreactor system. Thirty-six cancellous bone cores were harvested from bovine metatarsals at the time of slaughter and divided into five groups under the following conditions: Group 1) Isolated bone cores placed in static culture, Group 2) Unloaded bone cores placed in static culture in contact with a fiber-mesh metallic scaffold, Group 3) Bone cores placed in contact with a fiber-mesh metallic scaffold under the constant pressure of 150 kPa, Group 4) Bone core placed in contact with a fiber-mesh metallic scaffold and exposed to cyclic loading with continuous perfusion flow of media within the ex-vivo culture system and Group 5) Bone core evaluated on Day 0 to serve as a positive control for comparison with all other groups at weeks 4 and 7. Bone samples within Groups 1-4 were incubated for 4 and 7 weeks and then evaluated using histological examination (H&E) and the Live-Dead assay (Life Technologies). Matrix deposits on the metallic scaffolds were examined with scanning electron microscopy (SEM), while the chemical composition of the matrix was measured using energy-dispersive x-ray spectroscopy (EDX). We found that the viability of bone cores was maintained after seven weeks of loading in our ex vivo system. In addition, SEM images revealed crystallite-like structures on the dynamically loaded metal coupons (Group 4), corresponding to the initial stages of mineralization. EDX results further confirmed the presence of carbon at the interface and calcium phosphates in the matrix. We conclude that a bone bioreactor can be used as an alternate tool for in-vivo bone ingrowth studies of new implant surfaces or coatings.
最近，材料和制造工艺的进步使得制造复杂的植入物表面以促进骨附着成为可能。然而，这些新设计策略的改进和评估受到动物研究成本和复杂性的阻碍，特别是在开发过程的早期迭代阶段。为了解决这个问题，我们之前构建并验证了一种体外骨生物反应器培养系统，该系统可以在体外延长时间保持骨样本的活力。在这项研究中，我们使用体外生物反应器系统研究了钛金属网支架在静态和动态培养下的矿化情况。在屠宰时从牛的跖骨中采集了 36 个松质骨芯，并根据以下条件将其分为五组：组 1）单独的骨芯置于静态培养中，组 2）在静态培养中不加载的骨芯与纤维网金属支架接触，组 3）在 150kPa 的恒定压力下与纤维网金属支架接触的骨芯，组 4）与纤维网金属支架接触并在体外培养系统内连续灌注流动的介质中暴露于循环加载的骨芯，组 5）在第 0 天评估的骨芯作为阳性对照，与所有其他组在第 4 和 7 周进行比较。组 1-4 中的骨样本孵育 4 周和 7 周，然后使用组织学检查（H&E）和 Live-Dead 测定法（Life Technologies）进行评估。使用扫描电子显微镜（SEM）检查金属支架上的基质沉积物，并用能量色散 X 射线光谱法（EDX）测量基质的化学成分。我们发现，在我们的体外系统中，经过七周的加载后，骨芯的活力得以维持。此外，SEM 图像显示在动态加载的金属试片上（组 4）存在类似结晶的结构，对应于矿化的初始阶段。EDX 结果进一步证实了界面处存在碳和基质中的钙磷酸盐。我们得出结论，骨生物反应器可用作新植入物表面或涂层体内骨向内生长研究的替代工具。
