Korventausta Joni, Jokinen Mika, Rosling Ari, Peltola Timo, Yli-Urpo Antti
Turku Centre for Biomaterials, Institute of Dentistry, University of Turku, Häinen Pitkäkatu 4B, FIN-20520, Turku, Finland.
Biomaterials. 2003 Dec;24(28):5173-82. doi: 10.1016/s0142-9612(03)00425-3.
Sol-gel derived silicas are potential biomaterials both for tissue regeneration and drug delivery applications. In this study, both SiO(2) and calcium and phosphate-containing SiO(2) (CaPSiO(2)) are combined with poly-(DL-lactide) to form a composite. The main properties studied are the ion release rates of biologically important ions (soluble SiO(2) and Ca(2+)) and the formation of bone mineral-like calcium phosphate (CaP) on the composite surface. These properties are studied by varying the quality, content and granule size of silica gel in the composite, and porosity of the polymer. The results indicate that release rates of SiO(2) and Ca(2+) depend mostly on the formed CaP layer, but in some extent also on the granule size of silicas and polymer porosity. The formation of the bone mineral-like CaP is suggested to be induced by a thin SiO(-) layer on the composite surface. However, due to absence of active SiO(2) or CaPSiO(2) granules on the outermost surface, the suitable nanoscale dimensions do not contribute the nucleation and growth and an extra source for calcium is needed instead. The result show also that all composites with varying amount of CaPSiO(2) (10-60 wt%) formed bone mineral-like CaP on their surfaces, which provides possibilities to optimise the mechanical properties of composites.
溶胶 - 凝胶法制备的二氧化硅是用于组织再生和药物递送应用的潜在生物材料。在本研究中，二氧化硅（SiO₂）以及含钙和磷的二氧化硅（CaPSiO₂）均与聚（DL - 丙交酯）复合形成复合材料。所研究的主要性能包括生物重要离子（可溶性SiO₂和Ca²⁺）的离子释放速率以及复合材料表面骨矿物质样磷酸钙（CaP）的形成。通过改变复合材料中硅胶的质量、含量、颗粒尺寸以及聚合物的孔隙率来研究这些性能。结果表明，SiO₂和Ca²⁺的释放速率主要取决于形成的CaP层，但在一定程度上也取决于二氧化硅的颗粒尺寸和聚合物孔隙率。骨矿物质样CaP的形成被认为是由复合材料表面的一层薄SiO⁻层诱导的。然而，由于最外层表面不存在活性SiO₂或CaPSiO₂颗粒，合适的纳米级尺寸对成核和生长没有贡献，因此需要额外的钙源。结果还表明，所有含有不同量CaPSiO₂（10 - 60 wt%）的复合材料在其表面都形成了骨矿物质样CaP，这为优化复合材料的机械性能提供了可能性。
