Study of the mechanical stability and bioactivity of Bioglass® based glass-ceramic scaffolds produced via powder metallurgy-inspired technology
Study of the mechanical stability and bioactivity of Bioglass® based glass-ceramic scaffolds produced via powder metallurgy-inspired technology
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DOI：
10.1088/1748-6041/11/1/015005
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发表时间：
2016-02-01
影响因子：
4
通讯作者：
De Nardo, Luigi
中科院分区：
文献类型：
--
作者：
Boccardi, Elena;Melli, Virginia;De Nardo, Luigi
大的骨缺损很难愈合，通常需要骨传导和稳定的支持来帮助修复受损组织。基于生物玻璃的支架由于其刺激骨再生的能力而特别有希望用于这一目的。然而，目前采用的加工技术还不能合成具有合适力学性能的支架。此外，传统的烧结工艺导致玻璃脱玻璃，这产生了对生物活性的担忧。在这项工作中，我们研究了生物玻璃(R)基支架的生物活性和机械性能，该支架是通过粉末技术启发的工艺生产的。该支架的抗压强度在5-40 MPa范围内，即在目前报道的这些材料的上限范围内，具有可调节的孔隙率，在55%至77%之间，孔径为骨组织再生的最佳孔径（100-500 μ m）。将支架浸泡在模拟体液中28 d，分析支架力学性能和微观结构的演变。即使在烧结后发生了部分脱玻璃，浸泡在SBF中也会导致离子释放，并在2 d内形成Ca-P涂层，28 d后涂层厚度达到10-15 μ m。该涂层既含有羟基磷灰石，又含有无定形背景，表明基材的微观结构非晶化。浸泡28 d（抗压强度为6 MPa）后，支架仍保持良好的抗压强度和结构完整性。力学性能的下降主要与溶蚀引起的孔隙率增加有关，而与非晶化过程和Ca-P涂层的形成无关。这些结果表明，通过粉末冶金技术生产的生物玻璃(R)基支架是骨再生应用的优秀候选者。
Large bone defects are challenging to heal, and often require an osteoconductive and stable support to help the repair of damaged tissue. Bioglass-based scaffolds are particularly promising for this purpose due to their ability to stimulate bone regeneration. However, processing technologies adopted so far do not allow for the synthesis of scaffolds with suitable mechanical properties. Also, conventional sintering processes result in glass de-vitrification, which generates concerns about bioactivity. In this work, we studied the bioactivity and the mechanical properties of Bioglass (R) based scaffolds, produced via a powder technology inspired process. The scaffolds showed compressive strengths in the range of 5-40 MPa, i.e. in the upper range of values reported so far for these materials, had tunable porosity, in the range between 55 and 77%, and pore sizes that are optimal for bone tissue regeneration (100-500 mu m). We immersed the scaffolds in simulated body fluid (SBF) for 28 d and analyzed the evolution of the scaffold mechanical properties and microstructure. Even if, after sintering, partial de-vitrification occurred, immersion in SBF caused ion release and the formation of a Ca-P coating within 2 d, which reached a thickness of 10-15 mu m after 28 d. This coating contained both hydroxyapatite and an amorphous background, indicating microstructural amorphization of the base material. Scaffolds retained a good compressive strength and structural integrity also after 28 d of immersion (6 MPa compressive strength). The decrease in mechanical properties was mainly related to the increase in porosity, caused by its dissolution, rather than to the amorphization process and the formation of a Ca-P coating. These results suggest that Bioglass (R) based scaffolds produced via powder metallurgy-inspired technique are excellent candidates for bone regeneration applications.