【作者】 龚士强；

【导师】 毛靖；

【作者基本信息】 华中科技大学 ， 外科学， 2013， 博士

【摘要】 树脂材料是口腔医学临床实践中应用最广泛的一类医学材料。由于口腔为有菌环境这一特殊性，树脂材料的抗菌性能对于预防因细菌等微生物感染引起的口腔疾病（如龋齿，牙周病，口腔感染性粘膜病等）具有重要实际意义。抗菌性树脂材料可以抑制或者杀灭粘附在材料表面的细菌以消除或者抑制树脂材料表面微生物生物膜的形成。传统抗菌性树脂材料通常依赖抗菌成分释放机制实现。但是，通过释放机制的抗菌策略，在起始的“突释期”（Burst-release Phase）内可释放足量的抗菌成分而获得一定的抗菌效果。但是在随后的尾期释放（Tail-release Phase）中常常因为浓度太低难以达到有效抗菌浓度，同时可能诱导细菌耐受性。另外，材料中抗菌成分的释放，最终可能导致材料机械性能的下降。本论文报道利用凝胶-溶胶方法，合成一种可与甲基丙烯酸酯基树脂材料共聚和的抗菌性单体：季铵甲基丙烯酰氧基硅酸盐（QAMS）。在该合成体系前体物质中，正硅酸四乙酯（TEOS）为“锚”分子，连接具有广谱抗菌性能的三烷氧基硅烷SiQAC和具甲基丙烯酸酯基的3-MPTS。通过调整反应体系的pH和水含量，可控制QAMS的水解和缩合反应动力，以满足不同材料应用需求。将部分水解的QAMS-3PH整合入bis-GMA树脂系统后，bis-GMA/QAMS-3PH树脂材料具有对变形链球菌，内氏放线菌和白色念珠菌具有良好的抗菌效果；同时，树脂材料在水老化后，通过QAMS-3PH的继续水解缩合，材料表现出抗断裂性能的提升。全部水解的QAMS可溶解于MMA单体，从而整合于PMMA树脂系统，该树脂材料除表现出典型的长期接触杀菌效果外，其断裂韧度（Fracture Toughness）得到提升。最后，我们利用改良St ber方法，在水-乙醇反应体系中，以氨水为催化剂，在没有外加的表面活性剂的条件下，水解共聚合TEOS以及另外两个三烷氧基硅烷：SiQAC和3-MPTS，合成倍半硅氧烷-二氧化硅杂化物（SqSH）颗粒。通过改变反应前体物中TEOS与SiQAC/3-MPTS的比例，可得到不同弹性模量的SqSH颗粒。该颗粒除抗菌性能外，具有规则的板层状结构。更多还原

【Abstract】 Resin materials are one of the most common biomedical materials that are used inthe field of dentistry. The oral cavity harbors a variety of microorganisms, most of whichare considered as opportunistic pathogens. Uncontrolled accumulation of bacterial andfungal biofilms on or surrounding dental devices (i.e. resin materials) may contribute todental caries, periodontal disease, and infection-related stomatitis. Developing of resinmaterials with antimicrobial activities that combat bacteria within biofilm will be of greatinterest to both researchers and dental practitioners. Antimicrobial resin materials caninhibit or eliminate the formation of biofilm by inhibiting the adhesion of bacteria or killingbacteria upon contact. Conventional strategies are mainly relied on sustained release ofantimicrobial agents into surrounding environment. Leaching of antimicrobials frommaterials often displays a burst-release phase during the first few weeks after application.This phase is followed by a much lower, tail-release phase that is too low to be effectiveand may raise the problem of drug resistance. In addition, releasing of materials maydeteriorate the mechanical properties of material that leads to the fracture of the bulkmaterials.In this thesis, I am reporting the synthesis of a new class of methacrylatemacromonomers-quaternary ammonium methacryloxy silicate (QAMS) By usingtetraethoxysilane (TEOS) as the anchoring unit,3-(trimethoxysilyl)propyldimethy-loctadecyl ammonium chloride (SiQAC) and3-methacryloxypropyltrimethoxysilane (3-MPTS) are attached via a silane-based, sol-gelroute. By controlling the pH and the amount of water added into the system, QAMS withvaried degree of hydrolysis and condensation can be obtained. Partially hydrolyzed QAMS(QAMS-3PH) were covalently incorporated into bis-GMA resin system and shown to conferthe material with antimicrobial effects against Streptococcus mutans (S. mutans),Actinomyces naselundii (A. naeslundii) and Candida albicans (C. albicans). In addition, the bis-GMA/QAMS-3PHresin exhibited the potential of resistance to fracture via continuoushydrolysis and condensation after hydration. Besides improved fracture toughnessproperties, polymethyl methacrylate (PMMA) resin containing fully hydrolyzed QAMSretained the antimicrobial activities after water aging. Lastly, a modified St ber route wasadopted for synthesizing silsesquioxane-silica hybrid (SqSH) particles by hydrolyticco-condensation of TEOS with two trialkoxysilanes: SiQAC and3-MPTS, without the useof an additional surfactant. Their rheological behavior can be modified by varying theprecursor ratios, resulting in materials exhibiting rubbery or brittle characteristics. Besidesantimicrobial activities, lamellar structures were identified inside the particles.更多还原