African Material Science and Engineering Network (A Carnegie-IAS RISE Network), Johannesburg, South Africa.
University of the Witwatersrand School of Chemical and Metallurgical Engineering, Johannesburg, South Africa.
Sci Rep. 2018 Feb 27;8(1):3699. doi: 10.1038/s41598-018-22032-2.
In this work, glasses within the borosilicate borophosphate and phosphate family were sintered into 3D porous scaffolds using 60 and 70 vol. % NH(HCO) as a foaming agent. All scaffolds produced remained amorphous; apart from one third of the glasses which crystallized. All produced scaffolds had porosity >50% and interconnected pores in the range of 250-570 µm; as evidenced by µCT. The in-vitro dissolution of the scaffolds in SBF and changes in compression were assessed as a function of immersion time. The pH of the solution containing the borosilicate scaffolds increased due to the typical non-congruent dissolution of this glass family. Borophosphate and phosphate scaffolds induced a decrease in pH upon dissolution attributed to the congruent dissolution of those materials and the large release of phosphate within the media. As prepared, scaffolds showed compressive strength of 1.29 ± 0.21, 1.56 ± 0.63, 3.63 ± 0.69 MPa for the borosilicate, borophosphate and phosphate samples sintered with 60 vol. % NH (HCO), respectively. Evidence of hydroxyapatite precipitation on the borosilicate glass scaffolds was shown by SEM/EDS, XRD and ICP-OES analysis. The borophosphate scaffolds remained stable upon dissolution. The phosphate scaffolds were fully crystallized, leading to very large release of phosphate in the media.
在这项工作中，使用 60 和 70 体积%的 NH(HCO)作为发泡剂，将硼硅酸盐硼磷酸盐和磷酸盐家族的玻璃烧结成 3D 多孔支架。所有制备的支架都保持非晶态；除了三分之一的玻璃发生了晶化。所有制备的支架的孔隙率>50%，具有 250-570μm 范围内的互连孔；通过µCT 证明。支架在 SBF 中的体外溶解和压缩变化随浸泡时间而变化。由于该玻璃家族典型的非一致溶解，含硼硅酸盐支架的溶液的 pH 值增加。由于这些材料的一致溶解和介质中磷酸盐的大量释放，硼磷酸盐和磷酸盐支架在溶解时会降低 pH 值。在制备过程中，硼硅酸盐、硼磷酸盐和磷酸盐支架在分别用 60 体积%NH(HCO)烧结后，压缩强度为 1.29±0.21、1.56±0.63 和 3.63±0.69 MPa。SEM/EDS、XRD 和 ICP-OES 分析表明，硼硅酸盐玻璃支架上有羟基磷灰石沉淀的证据。在溶解过程中，硼磷酸盐支架保持稳定。磷酸盐支架完全结晶，导致介质中磷酸盐的大量释放。
