【作者】 韩媛媛；

【导师】 周长忍；

【作者基本信息】 暨南大学 ， 材料学， 2007， 硕士

【摘要】 壳聚糖作为磷酸钙骨水泥的改性材料已有许多文献报道，研究结果表明壳聚糖可以改善材料的临床适用性。但由于壳聚糖必须溶解在酸性溶液中，酸性液相限制了复合型骨水泥作为修复材料与细胞的复合性能。为了解决这一问题，本论文采用水溶性壳聚糖衍生物——羧甲基壳聚糖作为添加剂，并选用磷酸盐缓冲溶液作为液相溶剂，在控制固化初期pH值的基础上，研制出一种非酸性液相的壳聚糖改性磷酸钙骨水泥。首先，参照已有成熟技术制备了本研究所需的磷酸四钙(TTCP)、无水磷酸氢钙(DCPA)和羧甲基壳聚糖(CMC)。结合XRD、FTIR及分子量、脱乙酰度和取代度测定，结果表明得到了纯度较高TTCP和DCPA，其中TTCP不含有CaO及HAP杂质；CMC为N，O-型，黏均分子量M_η为4.61×10~5，脱乙酰度DD为94％，总取代度DS为0.94。通过对羧甲基壳聚糖(CMC)／磷酸钙复合骨水泥的理化性能研究表明：加入一定质量分数(＜4％)的羧甲基壳聚糖时，促凝增塑效果明显好于单纯的磷酸盐缓冲溶液。同时体系的抗压强度也有明显的提高，并改善了材料的抗稀散性。而分别以蒸馏水和0％-7％的CMC磷酸盐缓冲溶液作为液相，进行的磷酸钙骨水泥水化过程pH值变化研究结果表明：采用0％-7％的CMC磷酸盐缓冲溶液能明显控制浆体pH值变化。其中控制浆体pH值的主要因素是磷酸盐缓冲溶液，CMC几乎不影响浆体pH值变化。SBF模拟矿化实验中，结合ICP、FTIR、SEM及XRD分析表明：复合型磷酸钙骨水泥能够诱导溶液中Ca、P离子在材料表面的沉积，具有良好的生物活性；生成的HAP中含有与天然骨类似的B型碳酸磷灰石；CMC的加入对固化后材料的相组成不产生影响。通过初步的生物相容性评价试验得知，羧甲基壳聚糖复合磷酸钙骨水泥无细胞毒性，且符合溶血实验标准要求，是生物相容性良好的骨组织修复材料。更多还原

【Abstract】 Many reports on calcium phosphate cement showed that chitosan as an additive could improve the clinical applicability. However, chitosan can just be dissolved in acidic solution, which affected the property of the cements to composite with cells. In order to solve this proplem, we used in this paper a kind of water-soluble chitosan derivatives—carboxymethyl chitosan as an additive, and the phosphate buffered solution as the liquid solvent. On the basis of controlling the early pH value when setting, we made up a new type of calcium phosphate cement with non-acidic liquid.First, tetra-calcium phosphate (TTCP), anhydrous calcium hydrogen phosphate(DCPA), and carboxymethyl chitosan(CMC) needed in this research were prepared according to mature technologies. By XRD, FTIR and the determination of molecular weight, the degree of deacetylation(DD) and the degree of substitution(DS), the results showed that TTCP and DCPA had high purity, and TTCP did not contain CaO and HAP; N,O-carboxymethyl chitosan was prepared with the molecular weight of 4.61×10~5, and the degree of deacetylation and that of substitution was 94% and 0.94 respectively.By the research of chemical and physical properties of calcium phosphate cement with CMC as additive, we knew that addition of CMC in a limitied concentration scope(＜4%) could decrease the setting time effectively and raise the compressive strength; The pH value studies showed that the major factor which controlled the change of pH value was the phosphate buffered solution, and CMC gave little impact to slurry pH changes.The cement was immersed in the simulated body fluid(SBF) to test bioactivity. By the means of ICP, FTIR, SEM and XRD, the results showed that calcium phosphate cement contained CMC could induce deposition of Ca, P ions in the solution on the surface of materials, which demonstrated excellent bioactivity. HAP which was generated on the surface of materials contained a part of bone-like carbonated hydroxyapatite. We also knew from this study that the phase composition after CPC setting was not affected whether CMC was added or not. By the preliminary evaluation of biocompatibility, we got that calcium phosphate cement with CMC as additive had no cytotoxicity and meet the requirements of hemolytic standards well, which was a kind of bone tissue repairing materials with good biocompatibility.更多还原