用于牙髓损伤修复的新型微纳米生物活性玻璃的仿生制备及性能研究

发布时间：2018-10-05 07:38

【摘要】：当牙髓受到龋病和外伤的侵袭，容易引发牙髓损伤，从而影响牙齿的健康与功能，因此保存活髓或诱导牙髓牙本质再生是牙髓病学领域的研究热点。生物活性玻璃作为第三代生物活性材料具有生物相容性、骨传导和骨诱导性，是一类重要的骨修复材料，而牙本质的组成和形成机制与骨类似，提示它用于牙髓牙本质修复再生治疗的可能性。然而，传统生物活性玻璃易团聚、形貌不规则、尺寸结构不可控等问题影响了其活性离子的释放，限制了其在组织缺损修复中的应用。人体天然的组织因其具有独特的微纳米结构而展现出传统人工合成材料无法比拟的生物功能优势。因此从仿生角度出发，本文采用溶胶-凝胶技术结合有机模板自组装技术，设计制备了具有形貌、结构可控，尺寸、组分可调的新型微纳米生物活性玻璃，并研究了微纳米生物活性玻璃形貌、尺寸、结构的控制机理、物理化学性质以及体外磷灰石形成能力，研究了不同形貌、不同尺寸、不同组成的微纳米生物活性玻璃对人牙髓细胞增殖、分化行为的影响，并通过裸鼠皮下埋植生物活性玻璃与牙髓组织的复合体，考察生物活性玻璃在体内诱导牙髓细胞矿化的能力。主要研究工作和结论如下：（1）采用碱催化溶胶-凝胶技术结合模板自组装技术，，以溴化十六烷基三甲铵（CTAB）作为模板剂能够有效的控制生物活性玻璃颗粒的形态从球形（SBG）到短棒形（SRBG）再到长棒形（LRBG），孔结构从无序到有序，CTAB的浓度决定了颗粒的形态，催化剂氨水的浓度决定了颗粒的直径大小。三种形貌的生物活性玻璃均具有良好的体外磷灰石形成能力，且相比球形和短棒形颗粒，长棒形生物活性玻璃具有更强的体外磷灰石形成能力。生物活性玻璃颗粒对人牙髓细胞增殖与颗粒浓度有关，高浓度（200μg/mL）时对细胞增殖有抑制作用，低浓度（100μg/mL）时，能够促进细胞增殖。且在低浓度条件下，从促进细胞增殖和ALP蛋白表达的效果来看，SBG SRBG LRBG。（2）以十二胺（DDA）作为水解催化剂和结构形成模板剂，采用碱催化溶胶-凝胶技术结合模板协同组装技术能够有效制备出单分散微纳米生物活性玻璃球形颗粒（MBGS）。调节DDA加入量可以在微纳米尺寸范围内调控生物玻璃颗粒大小。体外磷灰石形成能力以及离子释放研究表明生物活性玻璃尺寸越小，离子释放速率更快，其体外磷灰石形成能力越强。在生物活性玻璃浓度为100μg/mL条件下，生物活性玻璃颗粒的尺寸大小对细胞增殖和ALP蛋白表达的影响有明显区别，更小尺寸的生物活性玻璃MBGS-1显示出更好的细胞相容性。（3）在第三章制备工艺基础之上，掺入一定量的Sr以取代Ca，制备掺Sr微纳米生物活性玻璃（BG-Sr），生物活性玻璃依然呈现单分散的规则微纳米球形形态，且对颗粒大小、晶相结构以及化学组成没有明显的影响，但随着Sr掺入量的增多，生物活性玻璃微球的比表面积增大，Si离子释放速度增大，体外磷灰石形成能力降低。Sr离子的浓度对细胞增殖和分化有一定影响，掺入适量的Sr（6mol%）呈现较好的细胞增殖能力、ALP分化能力以及细胞矿化能力，而当Sr掺入量达到15mol%时，其细胞增殖和分化能力都受到抑制。（4）采用溶胶-凝胶技术结合模板自组装技术，选用CTAB作为模板剂，氨水为催化剂，成功制备空腔大小可控的微纳米中空介孔生物活性玻璃球（HMBGS）。且平均粒径以及内部空腔随着醇水比的增大而增大，随CTAB浓度的增大而减小。同时HMBGS均具有较高的比表面积（444.003~609.512m2/g）和良好的体外磷灰石形成活性。（5）进一步考察生物活性玻璃体内诱导牙髓细胞矿化的能力，将45S5生物玻璃、58S生物玻璃以及单分散微纳米生物活性玻璃球MBGS分别与剪碎的裸鼠牙髓组织混合，进行皮下埋植6周后，通过HE染色和Masson染色观察发现，不会出现明显的炎症细胞，提示生物活性玻璃具有良好的生物相容性。三组生物活性玻璃均能够促进牙髓细胞外基质的分泌和矿化，且相比45S5组和58S组，MBGS组新生的矿化基质更多，提示MBGS促进矿化作用更强。
[Abstract]:When endodontic pulp is affected by caries and trauma, dental pulp injury can be easily induced, thus affecting the health and function of teeth. Bioactive glass, as the third generation bioactive material, has biocompatibility, bone conduction and osteoinducibility, is a kind of important bone repair material, and the composition and formation mechanism of dentin is similar to bone, suggesting it can be used in the treatment of dental pulp dentin repair and regeneration. However, the problems of easy agglomeration, irregular morphology and uncontrollable size structure of traditional bioactive glass affect the release of active ions and limit their application in tissue defect repair. the natural tissue of the human body exhibits the biological functional advantage of traditional artificial synthetic materials due to its unique micro-nano structure. Therefore, the micro-nano biological active glass with morphology, controllable structure, size and composition can be prepared by combining sol-gel technology and organic template self-assembly technology, and the morphology and size of micro-nano biological active glass are studied. The mechanism, physical and chemical properties of the structure and the ability of apatite formation in vitro were studied. The effects of different morphology, size and composition of micro-nano bioactive glass on the proliferation and differentiation of human dental pulp cells were studied. and the ability of bioactive glass to induce the mineralization of dental pulp cells in vivo is investigated through the composite of the biological active glass and the dental pulp tissue under the skin of the naked mouse. The main research work and conclusions are as follows: (1) adopting alkali catalysis sol-gel technology to combine template self-assembly According to the technology, the morphology of bioactive glass particles can be effectively controlled from spherical (SBG) to short rod shape (SRBG) to long rod shape (LRBG) as a template by using bromohexadecyltrimethylamine (CTAB) as a template agent, the concentration of ammonia in the catalyst determines the diameter of the particles, The bioactive glass with three kinds of morphology has good in vitro apatite forming ability, and has stronger in vitro apatite formation compared with spherical and short rod shaped particles. Ability. Bioactive glass particles have an inhibitory effect on cell proliferation at a high concentration (200 & mu; g/ mL) with respect to human dental pulp cell proliferation and particle concentration, and can promote cells at low concentrations (100 & mu; g/ mL) Proliferation. In low concentrations, SBG SRBG LR was seen from the effect of promoting cell proliferation and ALP expression. BG. (2) adopts dodecylamine (DDA) as the hydrolysis catalyst and structure to form template agent, and adopts alkali-catalyzed sol-gel technology combined with template co-assembly technology to effectively prepare monodisperse micro-nano biological active glass spherical particles (MBGS). Adjust the amount of DDA to adjust the bio-glass within the micro-nano-size range. Particle size, apatite formation ability in vitro and ion release study show that the smaller the size of bioactive glass, the faster the ion release rate and the apatite shape in vitro The stronger the bio-active glass particle size on cell proliferation and the expression of ALP protein under the condition of the bioactive glass concentration of 100. m u.g/ mL, the biological active glass MBGS-1 with smaller size is better than that of the biological active glass MBGS-1. Cell compatibility. (3) On the basis of the preparation of the third chapter, a certain amount of Sr is added to replace Ca, so as to prepare the Sr micro-nano biological active glass (BG-Sr), and the bioactive glass still exhibits a monodisperse regular micro-nano-spherical shape. In addition, with the increase of Sr incorporation, the specific surface area of bioactive glass microspheres increases, the release rate of Si ions increases, and in vitro phosphorus The concentration of Sr ions has a certain effect on cell proliferation and differentiation, and a proper amount of Sr (6mol%) has better cell proliferation ability, ALP differentiation ability and cell mineralization ability, but when Sr incorporation reaches 15mol%, its cell proliferation and differentiation (4) adopting a sol-gel technology combined template self-assembly technology, adopting CTAB as a template agent and ammonia as a catalyst, and successfully preparing the micro-nano hollow porous biological activity with controllable cavity size; The average particle size and the internal cavity increase with the increase of the water ratio of the alcohol, At the same time, HMBGS has higher specific surface area (444. 003 ~ 609. 512m2/ g) and good (5) the ability of biological active glass to induce the mineralization of dental pulp cells is further investigated, 45S5 biological glass, 58S biological glass and monodisperse micro-nano biological active glass spheres MBGS are respectively connected with the cut bare rat dental pulp. After 6 weeks of subcutaneous injection, the tissue was mixed and observed by HE staining and Masson staining, and no obvious inflammatory cells were present, suggesting that the organism The bioactive glass has good biocompatibility, and the three groups of bioactive glass can promote the secretion and mineralization of the extracellular matrix of the pulp, and compared with 45S5 and 58S, the MBGS group has more mineralized matrix,
【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R318.08;TQ317

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