Fiocco L, Li S, Stevens M M, Bernardo E, Jones J R
Dipartimento di Ingegneria Industriale, University of Padova, Via Marzolo, 9, 35131 Padova, Italy.
Department of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Acta Biomater. 2017 Mar 1;50:56-67. doi: 10.1016/j.actbio.2016.12.043. Epub 2016 Dec 23.
Magnesium is a trace element in the human body, known to have important effects on cell differentiation and the mineralisation of calcified tissues. This study aimed to synthesise highly porous Ca-Mg silicate foamed scaffolds from preceramic polymers, with analysis of their biological response. Akermanite (Ak) and wollastonite-diopside (WD) ceramic foams were obtained from the pyrolysis of a liquid silicone mixed with reactive fillers. The porous structure was obtained by controlled water release from selected fillers (magnesium hydroxide and borax) at 350°C. The homogeneous distribution of open pores, with interconnects of modal diameters of 160-180μm was obtained and maintained after firing at 1100°C. Foams, with porosity exceeding 80%, exhibited compressive strength values of 1-2MPa. In vitro studies were conducted by immersion in SBF for 21days, showing suitable dissolution rates, pH and ionic concentrations. Cytotoxicity analysis performed in accordance with ISO10993-5 and ISO10993-12 standards confirmed excellent biocompatibility of both Ak and WD foams. In addition, MC3T3-E1 cells cultured on the Mg-containing scaffolds demonstrated enhanced osteogenic differentiation and the expression of osteogenic markers including Collagen Type I, Osteopontin and Osteocalcin, in comparison to Mg-free counterparts. The results suggest that the addition of magnesium can further enhance the bioactivity and the potential for bone regeneration applications of Ca-silicate materials.
Here, we show that the incorporation of Mg in Ca-silicates plays a significant role in the enhancement of the osteogenic differentiation and matrix formation of MC3T3-E1 cells, cultured on polymer-derived highly porous scaffolds. Reduced degradation rates and improved mechanical properties are also observed, compared to Mg-free counterparts, suggesting the great potential of Ca-Mg silicates as bone tissue engineering materials. Excellent biocompatibility of the new materials, in accordance to the ISO10993-5 and ISO10993-12 standard guidelines, confirms the preceramic polymer route as an efficient synthesis methodology for bone scaffolds. The use of hydrated fillers as porogens is an additional novelty feature presented in the manuscript.
镁是人体中的一种微量元素，已知对细胞分化和钙化组织的矿化有重要影响。本研究旨在由陶瓷前驱体聚合物合成高度多孔的钙镁硅酸盐泡沫支架，并分析其生物学反应。通过将液态硅酮与反应性填料混合热解得到钙黄长石（Ak）和硅灰石 - 透辉石（WD）陶瓷泡沫。通过在350°C下从选定的填料（氢氧化镁和硼砂）中控制水分释放来获得多孔结构。在1100°C烧制后，获得并保持了具有160 - 180μm模态直径互连的开孔均匀分布。孔隙率超过80%的泡沫表现出1 - 2MPa的抗压强度值。通过在模拟体液（SBF）中浸泡21天进行体外研究，结果显示出合适的溶解速率、pH值和离子浓度。按照ISO10993 - 5和ISO10993 - 12标准进行的细胞毒性分析证实了Ak和WD泡沫均具有优异的生物相容性。此外，与不含镁的支架相比，在含镁支架上培养的MC3T3 - E1细胞表现出增强的成骨分化以及包括I型胶原蛋白、骨桥蛋白和骨钙素在内的成骨标志物的表达。结果表明，镁的添加可以进一步增强钙硅酸盐材料的生物活性和骨再生应用潜力。
在此，我们表明在聚合物衍生的高度多孔支架上培养时，镁掺入钙硅酸盐中对MC3T3 - E1细胞的成骨分化和基质形成增强起着重要作用。与不含镁的对应物相比，还观察到降解速率降低和机械性能改善，这表明钙镁硅酸盐作为骨组织工程材料具有巨大潜力。根据ISO10993 - 5和ISO10993 - 12标准指南，新材料具有优异的生物相容性，证实了陶瓷前驱体聚合物路线是一种用于骨支架的有效合成方法。使用水合填料作为致孔剂是本文稿中呈现的另一个新颖特征。
