1 Department of Orthopedic Surgery, Yeungnam University Medical Center, Daegu, Korea.
2 Materials Science and Engineering, Yeungnam University, Gyeongbuk, Republic of Korea.
J Biomater Appl. 2018 Aug;33(2):196-204. doi: 10.1177/0885328218783585. Epub 2018 Jun 27.
Background In this study, the properties of the water glass (WG, sodium-silicate glass) were utilized to control the biodegradability of the beta tricalcium phosphate materials by the WG coating on the tricalcium phosphate disc surface with various coating thickness, chemistry, and heat-treatment. Methods Four types of disc specimens were prepared. A sample group A consisted of pure hydroxyapatite (HA) as a negative resorption control; a sample group B consisted of pure beta tricalcium phosphate as a positive resorption control; a sample group C consisted of beta tricalcium phosphate coated with WG as an early resorption model; and a sample group D consisted beta tricalcium phosphate coated with WG and heat-treated at 500°C as a delayed resorption model. Using human bone marrow-derived mesenchymal stem cells, for the analysis of cellular attachment and proliferative activity, 4-6-Diamidino-2-Phenylindole fluorescence technique was used. For the analysis of osteteogenic differentiation, alkaline phospastase (ALP) activity was measured. Results The mean z-scores of four groups (A, B, C, and D) in cellular attachment at 4 h after seeding were -1.21, -0.15, 0.42, and 0.94, respectively, and statistically significantly different in all groups respectively. Seven days after seeding, the mean z-scores of cellular proliferation were 1.97, 0.71, 1.48, and 1.83 in the four groups, respectively. The mean z-scores of the ALP activity per the mean z-scores of cell numbers of respective groups on the seventh day were 0.40, -1.51, 0.12, and 0.06, respectively, in four groups. Conclusion Initial cellular attachment is better on beta tricalcium phosphate than on HA and is enhanced by WG coating, especially with sintering at the high temperature. Cellular proliferation is considered to be increased by maintaining its attachment site through reduced dissolution of beta tricalcium phosphate by WG coating. Osteogenic differentiation in in-vitro study on the WG-coated beta tricalcium phosphate is thought to be as the result of increased silicon ion release from the WG.
在这项研究中，利用水玻璃（WG，硅酸钠玻璃）的性质，通过在磷酸三钙盘表面涂覆 WG 来控制磷酸三钙材料的生物降解性，涂层厚度、化学成分和热处理方式各不相同。
制备了 4 种类型的圆盘试样。A 组为纯羟基磷灰石（HA）作为阴性再吸收对照；B 组为纯β-磷酸三钙作为阳性再吸收对照；C 组为 WG 涂层的β-磷酸三钙作为早期再吸收模型；D 组为 WG 涂层并在 500°C 下热处理的β-磷酸三钙作为延迟再吸收模型。采用人骨髓间充质干细胞，通过 4-6-二脒基-2-苯基吲哚荧光技术分析细胞黏附及增殖活性，通过碱性磷酸酶（ALP）活性分析成骨分化。
细胞接种后 4 小时，A、B、C、D 四组的平均 z 分数分别为-1.21、-0.15、0.42 和 0.94，各组间差异均有统计学意义。接种后 7 天，四组细胞增殖的平均 z 分数分别为 1.97、0.71、1.48 和 1.83。第 7 天各组细胞数平均 z 分数与 ALP 活性平均 z 分数之比分别为 0.40、-1.51、0.12 和 0.06。
β-磷酸三钙的初始细胞黏附优于 HA，并且通过 WG 涂层增强，特别是在高温下烧结后效果更为明显。通过 WG 涂层减少β-磷酸三钙的溶解，维持其黏附部位，从而认为细胞增殖增加。在 WG 涂层的β-磷酸三钙的体外成骨分化被认为是由于 WG 释放的硅离子增加所致。
