载微球壳聚糖引导骨组织再生膜的制备及力学性能研究

发布时间：2018-01-17 15:27

本文关键词：载微球壳聚糖引导骨组织再生膜的制备及力学性能研究　出处：《太原理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：骨缺损的再生修复已成为目前再生医学研究的重要课题。大量研究表明引导骨组织再生膜(GBR)技术是一种治疗骨缺损的有效方法。临床上要求GBR膜需具有良好生物相容性、生物活性和骨传导性,并具有一定的力学强度以抵抗周围纤维组织的侵入。本研究采用具有良好生物相容性、生物降解性的壳聚糖(CS)制备了GBR膜,为改善GBR膜的力学强度及成骨活性,在GBR膜中引入纳米羟基磷灰石(nHA)与CS复合微球,期望该膜在起到屏障作用的同时,兼具良好的骨传导作用,促进骨缺损的再生修复。前期研究大多采用结合乳化原理的共混法来制备复合微球,本研究采用原位仿生技术制备nHA/CS复合微球,充分利用无机纳米粒子(nHA)表面活性较高和比表面积较大的优点,将其均匀分散在高分子基质(CS)中与活性基团产生化学键结合,获得各方面性能理想的复合微球,并与使用共混原理制备的复合微球进行了比较和分析研究。利用扫描电镜(SEM)、 X射线能谱(EDS)、X射线衍射(XRD)、红外(FTIR)和激光粒度仪等手段对不同微球的理化性能进行表征。结果表明：相比共混法,原位仿生制备的nHA/CS复合微球形态圆整均匀,分散性好,粒径分布较窄,平均粒径为8.62μm, nHA晶体均匀分布在微球内部及表面并与CS基质以化学键结合。设计并制备分别载有纯CS微球、原位仿生nHA/CS复合微球以及共混nHA/CS复合微球的新型GBR膜。通过SEM对比观察三种引导骨组织再生膜表面或断面的形貌及结构,研究不同微球在GBR膜内及表面分布情况,并采用万能电子试验机对三种膜进行力学性能测试。结果显示,引入不同微球后GBR膜表面有颗粒状突起,微球均包覆在GBR膜内部。断面结构显示,CS微球与CS基质之间有明显空隙,共混法nHA/CS复合微球中nHA团聚形成较大团簇,不利于复合微球与CS基质的结合,而原位法nHA/CS复合微球与CS基质结合较为紧密,微球表面nHA晶体能有效连接微球与CS基质。拉伸实验表明,相比纯CS膜,引入不同微球后,断裂伸长率均有所下降,其中原位法复合微球断裂伸长率最大,达到5.61±0.95%。相比纯CS膜,引入CS微球后,其弹性模量和强度极限有所下降,而共混法与原位法复合微球组均有所升高,原位法弹性模量和强度极限达到最大,分别为766.272±20.675和43.318±0.951MPa。
[Abstract]:The regeneration and repair of bone defects has become an important subject in regenerative medicine. A large number of studies have shown that the bone tissue regeneration membrane can be guided by GBR. Technology is an effective method for the treatment of bone defect. It is necessary to have good biocompatibility of GBR membrane in clinic. Biological activity, bone conductivity, and a certain degree of mechanical strength to resist the invasion of surrounding fibrous tissue. In order to improve the mechanical strength and osteogenic activity of GBR membrane, GBR membrane was prepared by chitosan with good biocompatibility and biodegradability. Nano-hydroxyapatite (HA) and CS composite microspheres were introduced into the GBR membrane. It is expected that the composite microspheres not only act as a barrier but also have good bone conduction and promote the regeneration and repair of bone defects. In previous studies, most of the composite microspheres were prepared by blending with emulsification principle. In this study, nHA/CS composite microspheres were prepared by in situ bionic technology. Taking full advantage of the advantages of high surface activity and large specific surface area of inorganic nano-particles (NHAs), they were uniformly dispersed in the polymer matrix (CSS) to form chemical bonds with active groups. The composite microspheres with ideal properties in various aspects were obtained and compared with the composite microspheres prepared by using the blending principle. The scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS) were used to prepare the composite microspheres. The physicochemical properties of different microspheres were characterized by X-ray diffraction (XRD), FTIR (FTIR) and laser particle size analyzer. The nHA/CS composite microspheres prepared by in situ bionics have the advantages of uniform morphology, good dispersion, narrow particle size distribution and average particle size of 8.62 渭 m. The nHA crystal is uniformly distributed inside and on the surface of the microsphere and binds to the CS substrate by chemical bond. The pure CS microspheres were designed and prepared. In situ biomimetic nHA/CS composite microspheres and blend nHA/CS composite microspheres of a new GBR membrane. The morphology and structure of three kinds of guided bone tissue regeneration membrane surface or section were observed by SEM. The distribution of different microspheres in and on the surface of GBR film was studied, and the mechanical properties of three kinds of membranes were tested by universal electronic testing machine. The results showed that there were granular protrusions on the surface of GBR film after the introduction of different microspheres. The cross section structure showed that there was a clear void between CS microspheres and CS matrix, and nHA agglomerated into large clusters in nHA/CS composite microspheres by blending. It is not conducive to the binding of composite microspheres to CS matrix, while in situ nHA/CS composite microspheres bind more closely to CS matrix. The nHA crystal on the surface of the microspheres can effectively connect the microspheres to the CS substrate. The tensile experiments show that the elongation at break decreases with the addition of different microspheres compared with the pure CS films. The elongation at break of in-situ composite microspheres reached 5.61 卤0.95.Compared with the pure CS film, the elastic modulus and the strength limit of the composite microspheres decreased after the introduction of CS microspheres. The elastic modulus and strength limit of in-situ method reached the maximum of 766.272 卤20.675 and 43.318 卤0.951 MPa, respectively.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R318.08

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