Synthesis of apatite-organic polymer hybrid materials by chemical modification

本文研究了在离子浓度接近人血浆的模拟体液（SBF）或离子浓度为SBF 1.5倍的模拟溶液（1.5SBF）中，通过仿生工艺合成类骨磷灰石-有机聚合物杂化材料。主要结果包括：1。通过与含三乙氧基硅烷偶联剂反应，再水解缩聚四乙氧基硅烷，对乙烯-乙烯醇共聚物底物和针织纤维表面进行硅醇（Si-OH）基改性。硅醇改性后的样品在1.5SBF条件下，几周内表面就会形成磷灰石层。此外，经硅酸钙溶液处理的试样，即使在SBF中，也能在几天内形成磷灰石，说明钙离子引入表面硅酸盐层，增强了磷灰石的形成能力。结果表明，羧甲基纤维素、羧甲基几丁质和结冷胶制备的凝胶经饱和Ca(OH)_2溶液处理后，在SBF中3 d内表面形成磷灰石。海藻酸钙凝胶和纤维原本具有羧基和钙离子，在SBF中一周内也形成了磷灰石。这些结果表明，凝胶上的羧酸基团对磷灰石成核是有效的，钙离子的掺入可以提高聚合物的磷灰石形成能力。综上所述，通过简单的化学修饰和仿生过程的结合，发现各种类型的聚合物是获得具有骨状结构的磷灰石-聚合物杂合体的有希望的候选者。

In this research was investigated the synthesis of bonelike apatite-organic polymer hybrid materials via a biomimetic process in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma or a solution (1.5SBF) with ion concentrations 1.5 times those of SBF.Main results include :1. The surface of ethylene-vinyl alcohol copolymer substrates and knitted fibers were modified with silanol (Si-OH) groups by the reaction with a triethoxysilyl group-containing silane coupling agent and the subsequent hydrolysis and polycondensation of tetraethoxysilane. The silanol-modified specimens were found to form apatite layer on them within a few weeks in 1.5SBF.Moreover, the specimens treated with calcium silicate solution can form apatite within a few days even in SBF, indicating introduction of calcium ions into the surface silicate layer brings about the enhanced apatite-forming ability.2. It was found that the gels prepared from carboxymethyl (CM) cellulose, CM-chitin and gellan gum, all of which possess carboxylate functions, formed apatite on their surfaces within 3 days in SBF, when they were previously treated with a saturated Ca(OH)_2 solution. Calcium alginate gels and fibers originally having carboxyl groups and calcium ions also formed apatite on them within a week in SBF.These results indicate that the carboxylate groups on the gels are effective for the apatite nucleation and the apatite forming ability of the polymer can be improved by incorporation of the calcium ions.In conclusion, various types of polymers were found to be promising candidates for obtaining apatite-polymer hybrids with bonelike structure through a combination of simple chemical modifications and biomimetic process.