Department of Periodontics and Preventive Dentistry, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Center for Craniofacial Regeneration, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Center for Craniofacial Regeneration, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Acta Biomater. 2015 Dec;28:234-239. doi: 10.1016/j.actbio.2015.08.037. Epub 2015 Aug 28.
Magnesium (Mg) alloys have many unique qualities which make them ideal candidates for bone fixation devices, including biocompatibility and degradation in vivo. Despite a rise in Mg alloy production and research, there remains no standardized system to assess their degradation or biological effect on human stem cells in vivo. In this study, we developed a novel in vivo model to assess Mg alloys for craniofacial and orthopedic applications. Our model consists of a collagen sponge seeded with human bone marrow stromal cells (hBMSCs) around a central Mg alloy rod. These scaffolds were implanted subcutaneously in mice and analyzed after eight weeks. Alloy degradation and biological effect were determined by microcomputed tomography (microCT), histological staining, and immunohistochemistry (IHC). MicroCT showed greater volume loss for pure Mg compared to AZ31 after eight weeks in vivo. Histological analysis showed that hBMSCs were retained around the Mg implants after 8 weeks. Furthermore, immunohistochemistry showed the expression of dentin matrix protein 1 and osteopontin around both pure Mg and AZ31 with implanted hBMSCs. In addition, histological sections showed a thin mineral layer around all degrading alloys at the alloy-tissue interface. In conclusion, our data show that degrading pure Mg and AZ31 implants are cytocompatible and do not inhibit the osteogenic property of hBMSCs in vivo. These results demonstrate that this model can be used to efficiently assess the biological effect of corroding Mg alloys in vivo. Importantly, this model may be modified to accommodate additional cell types and clinical applications.
Magnesium (Mg) alloys have been investigated as ideal candidates for bone fixation devices due to high biocompatibility and degradation in vivo, and there is a growing need of establishing an efficient in vivo material screening system. In this study, we assessed degradation rate and biological effect of Mg alloys by transplanting Mg alloy rod with human bone marrow stromal cells seeded on collagen sponge subcutaneously in mice. After 8 weeks, samples were analyzed by microcomputed tomography and histological staining. Our data show that degrading Mg alloys are cytocompatible and do not inhibit the osteogenic property of hBMSCs in vivo. These results demonstrate that this model can be used to efficiently assess the biological effect of corroding Mg alloys in vivo.
镁（Mg）合金具有许多独特的性质，使其成为骨固定装置的理想候选材料，包括生物相容性和体内降解性。尽管镁合金的生产和研究有所增加，但仍没有标准化的系统来评估其在体内对人类干细胞的降解或生物学影响。在这项研究中，我们开发了一种新的体内模型来评估用于头面部和骨科应用的镁合金。我们的模型由一个中央镁合金棒周围的胶原海绵组成，海绵中种植有人骨髓基质细胞（hBMSCs）。这些支架被植入小鼠的皮下，并在八周后进行分析。通过微计算机断层扫描（microCT）、组织学染色和免疫组织化学（IHC）来确定合金的降解和生物学效应。microCT 显示，在体内 8 周后，纯镁的体积损失大于 AZ31。组织学分析显示，在 8 周后，hBMSCs 仍保留在镁植入物周围。此外，免疫组织化学显示，在植入 hBMSCs 后，纯镁和 AZ31 周围均表达牙本质基质蛋白 1 和骨桥蛋白。此外，组织学切片显示，在所有降解合金的合金-组织界面处均有一层薄的矿物质层。总之，我们的数据表明，降解的纯镁和 AZ31 植入物是细胞相容的，并且不会抑制 hBMSCs 的成骨特性。这些结果表明，该模型可用于有效地评估体内腐蚀性镁合金的生物学效应。重要的是，该模型可以修改以适应额外的细胞类型和临床应用。
镁（Mg）合金由于高生物相容性和体内降解性而被研究为理想的骨固定装置候选材料，因此建立有效的体内材料筛选系统的需求日益增长。在这项研究中，我们通过将带有种植在胶原海绵上的人骨髓基质细胞的镁合金棒移植到小鼠的皮下，评估镁合金的降解率和生物学效应。8 周后，通过 microCT 和组织学染色对样本进行分析。我们的数据表明，降解的镁合金是细胞相容的，并且不会抑制 hBMSCs 的体内成骨特性。这些结果表明，该模型可用于有效地评估体内腐蚀性镁合金的生物学效应。
