In vitro degradation of calcium phosphates: Effect of multiscale porosity, textural properties and composition
In vitro degradation of calcium phosphates: Effect of multiscale porosity, textural properties and composition
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DOI：
10.1016/j.actbio.2017.07.033
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发表时间：
2017-09-15
影响因子：
9.7
通讯作者：
Ginebra, M. -P.
中科院分区：
文献类型：
--
作者：
Diez-Escudero, A.;Espanol, M.;Ginebra, M. -P.
磷酸钙被骨替代的能力与其可吸收性密切相关。然而，一些结构参数对其降解行为的相对重要性仍不清楚。本研究旨在量化不同长度尺度（纳米、微米和大孔隙）的成分、比表面积（SSA）和孔隙率对不同磷酸钙体外降解的影响。在酸性介质中进行降解研究以模拟破骨细胞环境。尽管具有高度多孔性（35-65%），但尺寸小于 3 gm 的互连纳米孔和微孔样品中发现了轻微的降解，最大重量损失为 8 wt%。仿生缺钙羟基磷灰石具有高 SSA 和低结晶度，具有最高的降解率，甚至超过了更易溶解的 β-TCP。当孔隙率和孔径增加时，降解对 SSA 的依赖性是无可争议的。引入具有超过 20 gm 的孔互连的额外大孔隙会显着影响降解，在具有高 SSA (>15 m(2)/g) 的基材中更为明显，而在具有低 SSA 的烧结基材中（>15 m(2)/g）。
The capacity of calcium phosphates to be replaced by bone is tightly linked to their resorbability. However, the relative importance of some textural parameters on their degradation behavior is still unclear. The present study aims to quantify the effect of composition, specific surface area (SSA), and porosity at various length scales (nano-, micro- and macroporosity) on the in vitro degradation of different calcium phosphates. Degradation studies were performed in an acidic medium to mimic the osteoclastic environment. Small degradations were found in samples with interconnected nano- and micropores with sizes below 3 gm although they were highly porous (35-65%), with maximum weight loss of 8 wt%. Biomimetic calcium deficient hydroxyapatite, with high SSA and low crystallinity, presented the highest degradation rates exceeding even the more soluble beta-TCP. A dependence of degradation on SSA was indisputable when porosity and pore sizes were increased. The introduction of additional macroporosity with pore interconnections above 20 gm significantly impacted degradation, more markedly in the substrates with high SSA (>15 m(2)/g), whereas in sintered substrates with low SSA (