【作者】 雷勇；

【导师】 胡巧玲；

【作者基本信息】 浙江大学 ， 材料物理与化学， 2005， 硕士

【摘要】 本文在原有工作的基础上,将壳聚糖棒材作为骨折内固定材料为应用目标,针对骨修复材料表面的特殊性、棒材在湿态环境下力学性能衰减过快以及熔融涂覆防水层大大延缓壳聚糖棒材的降解等一系列问题。本文通过分步法制备具有CS/HA复合外层的壳聚糖棒材改进棒材表面的疏水性;通过对自然界中存在的暂时性拒水植物叶进行仿生,通过溶剂法涂覆壳聚糖棒材以达到在湿态环境下在骨折愈合初期维持足够的力学强度同时又能适时降解;并对生物酯和壳聚糖棒材进行了生物学评价。1. 在原有的原位杂化法与间歇沉析法的基础上,提出一种新型羟基磷灰石涂层组装方法--分步法。制备出具有壳聚糖/羟基磷灰石复合涂层的壳聚糖棒材。通过与交替沉积法组装CS/HA涂层对比,对具有CS/HA涂层棒材进行了表面接触角、吸水率以及力学性能等测试。测试结果表明:具有CS/HA复合涂层的壳聚糖棒材能在保持一定的力学性能的情况下有效地增大棒材表明的接触角,但无法降低其吸水率。2. 通过对自然界中存在的暂时性拒水植物叶的拒水机理以及表面成分进行仿生,采用溶剂法在壳聚糖棒材表面涂覆生物酯防水层。生物酯的涂覆能有效地降低棒材表面接触角且能有效降低壳聚糖棒材的吸水率。对涂覆不同次数防水层后棒材的表面接触角及其吸水率进行评价;并通过湿态环境下三次涂覆后棒材的力学性能衰减速率的快慢对涂层拒水效果进行了评价。3. 对壳聚糖棒材和生物酯的细胞毒性以及壳聚糖棒材的角结膜刺激性和生物酯的溶血性进行了评价。结果表明:壳聚糖棒材无细胞毒性,无刺激性;生物酯无细胞毒性,不引起溶血反应,可以满足医用生物材料的应用要求。更多还原

【Abstract】 The attenuation of mechanic intensity of chitosan rods is rapid due to their high water penetrating rate and large amount of water adsorption, which limits their practical application as internal fixation of bone frature. In this thesis , chitosan/hydroxyapatite composite layers and bio-ester coatings were prepared for surface hydroprobiztion of chitosan rods, and the biological safety of chitosan rod and bio-ester were evaluated.1. Based on the in-situ hybridization and the intermittently precipitation, the CS/HA composite layers were prepared by a novel and simple two-step method. XRD and ED AX were used to determine component of the composite. The mechanical properties of the composite were evaluated, and the effects of time in coagulator A and alternate soaking cycles on bending strength of CS/HA composite rod were discussed.2. Many terrestrial plants and animals are water-repellent due to hydrophobic surface components in connection with a microscopic roughness. Leaves that are water-repellent for only a short period of time have only slightly convex epidermal cells and often have a less dense wax layer. Bio-ester solution coating was adopted as the method of surface hydrophobic modification of chitosan rod. Then the water-repellent effect was characterized by contact angle and water absorption rate. Soaked in SBF three months, mechanical properties attenuation showed that the surface modification mimicking microstructure of the plant leaf is a method of feasibility to improve water-repellent property of the chitosan rod.3. To evaluate the biological safety of chitosan rod and bio-ester, the cytotoxicity test, hemolysis test and eye sensitivity test were investigated with standard method. Bio-ester was no cytotoxicity and almost no obvious hemolysis. Chitosan rods were no cytotoxicity and no sensitivity. The chitosan rods andbio-ester have excellent biocompatibility and biological safety for the clinical application in the future.更多还原