Mebarki Miryam, Coquelin Laura, Layrolle Pierre, Battaglia Séverine, Tossou Marine, Hernigou Philippe, Rouard Hélène, Chevallier Nathalie
IMRB U955-E10, INSERM, Creteil, France; Faculty of Medicine, Paris Est University, Creteil, France; Engineering and Cellular Therapy Unit, Etablissement Français du Sang, Créteil, France.
INSERM U957, Lab. Pathophysiology of Bone Resorption, Faculty of Medicine, University of Nantes, Nantes, France.
Acta Biomater. 2017 Sep 1;59:94-107. doi: 10.1016/j.actbio.2017.06.018. Epub 2017 Jun 19.
In order to induce an efficient bone formation with human bone marrow mesenchymal stromal cells (hBMSC) associated to a scaffold, it is crucial to determine the key points of the hBMSC action after in vivo transplantation as well as the appropriate features of a scaffold. To this aim we compared the hBMSC behavior when grafted onto two biomaterials allowing different bone potential in vivo. The cancellous devitalized Tutoplast®-processed bone (TPB) and the synthetic hydroxyapatite/β-tricalcium-phosphate (HA/βTCP) which give at 6weeks 100% and 50% of bone formation respectively. We first showed that hBMSC adhesion is two times favored on TPB in vitro and in vivo compared to HA/βTCP. Biomaterial structure analysis indicated that the better cell adhesion on TPB is associated to its higher and smooth open pore architecture as well as its content in collagen. Our 6week time course analysis, showed using qPCR that only adherent cells are able to survive in vivo giving thus an advantage in term of cell number on TPB during the first 4weeks after graft. We then showed that grafted hBMSC survival is crucial as cells participate directly to bone formation and play a paracrine action via the secretion of hIGF1 and hRANKL which are known to regulate the bone formation and resorption pathways respectively. Altogether our results point out the importance of developing a smooth and open pore scaffold to optimize hBMSC adhesion and ensure cell survival in vivo as it is a prerequisite to potentiate their direct and paracrine functions.
Around 10% of skeletal fractures do not heal correctly causing nonunion. An approach involving mesenchymal stromal cells (MSC) associated with biomaterials emerges as an innovative strategy for bone repair. The diversity of scaffolds is a source of heterogeneity for bone formation efficiency. In order to better determine the characteristics of a powerful scaffold it is crucial to understand their relationship with cells after graft. Our results highlight that a biomaterial architecture similar to cancellous bone is important to promote MSC adhesion and ensure cell survival in vivo. Additionally, we demonstrated that the grafted MSC play a direct role coupled to a paracrine effect to enhance bone formation and that both of those roles are governed by the used scaffold.
为了通过与支架相关联的人骨髓间充质基质细胞（hBMSC）诱导高效的骨形成，确定体内移植后hBMSC作用的关键点以及支架的合适特性至关重要。为此，我们比较了将hBMSC移植到两种在体内具有不同骨生成潜力的生物材料上时的行为。失活的松质骨Tutoplast®处理骨（TPB）和合成的羟基磷灰石/β-磷酸三钙（HA/βTCP），在6周时分别有100%和50%的骨形成。我们首先表明，与HA/βTCP相比，hBMSC在体外和体内对TPB的粘附力要强两倍。生物材料结构分析表明，hBMSC在TPB上更好的细胞粘附与其更高且光滑的开孔结构以及胶原蛋白含量有关。我们为期6周的时间进程分析显示，使用qPCR检测发现只有粘附细胞能够在体内存活，因此在移植后的前4周内，TPB上的细胞数量具有优势。然后我们表明，移植的hBMSC存活至关重要，因为细胞直接参与骨形成，并通过分泌已知分别调节骨形成和吸收途径的hIGF1和hRANKL发挥旁分泌作用。总之，我们的结果指出了开发一种光滑且开孔的支架以优化hBMSC粘附并确保其在体内存活的重要性，因为这是增强其直接和旁分泌功能的先决条件。
约10%的骨骼骨折无法正确愈合导致骨不连。一种涉及与生物材料相关联的间充质基质细胞（MSC）的方法作为一种创新的骨修复策略出现。支架的多样性是骨形成效率异质性的一个来源。为了更好地确定强大支架的特性，了解移植后它们与细胞的关系至关重要。我们的结果强调，类似于松质骨的生物材料结构对于促进MSC粘附并确保其在体内存活很重要。此外，我们证明移植的MSC在增强骨形成方面发挥直接作用并伴有旁分泌效应，并且这两种作用均受所用支架的支配。
