导电纳米纤维的制备及生物学性能研究

发布时间：2018-11-18 18:43

【摘要】：纳米技术发展迅速,静电纺丝技术作为一种简单、快捷、方便的纳米材料制备方法,被广泛的用来制备各种各样的纳米材料。在生物医学工程领域,该技术被用来制备各种仿生材料,以用来治疗、修复或者替换人体受伤的组织或器官。聚酰胺(PA)的分子结构中含有很多的极性酰胺基团(-CO-NH-),它可以为细胞和生物组织提供友好的界面,具有良好的细胞相容性。使用PA的甲酸溶液进行静电纺丝制备PA纳米纤维,探索主要的电纺参数,如电压、接收距离、湿度、温度等,溶液参数,如浓度等对PA纳米纤维微观形貌及直径的影响。碳纳米管(CNTs)是由六个碳原子组成的六边形单元相互连接而构成的数层的同轴圆管,其独特的物理化学性质使它具有良好的生物相容性、机械性能和导电性,使它在生物医学领域有广泛的应用。制备PA/CNTs复合纳米纤维,探索CNTs对复合纤维性能的影响。盐酸小檗碱为黄连的提取物,抗菌谱广,可通过人体正常代谢或吸收,对正常组织毒副作用小,以此为药物模型制备载药PA纳米纤维、载药PA/CNTs复合纳米纤维。通过扫描电镜(SEM)对纳米纤维的微观形貌进行观察;万能材料试验机对纳米纤维膜的力学性能进行测试;四探针测试台对湿润状态下的纳米纤维膜的导电性进行测试;能谱仪(EDS)对所载药物的分布进行测试;体外药物释放试验测试载药纳米纤维的药物缓释性能;固体和液体培养基的培养,测试载药纳米纤维对大肠杆菌的抑菌性;将小鼠成纤维细胞(L929)接种在纳米纤维膜上测试其生物相容性进行。结果表明:随PA浓度和电压的增大,纤维直径均会变粗,浓度增大时粘连减少。当接收距离增大,纤维直径呈减小的趋势。当空气湿度较大时,纤维直径变细,但是有小微球出现,纤维之间的粘连比较严重。当环境温度比较高时(45℃),纤维形貌比较好,而比较低时(30℃),会出现纤维和微球的复合物。PA的甲酸溶液浓度为12wt%,电压为18 k V,接收距离为12 cm,温度为45℃,湿度为16%时纤维的形貌相对比较好。CNTs对复合纤维的形貌没有明显的影响,但是显著的增强了PA/CNTs复合纳米纤维的力学性能,CNTs含量的增加会使PA/CNTs复合纳米纤维的直径减小,导电性增强。当CNTs含量为0.9wt%时,PA/CNTs复合纳米纤维膜的弹性模量和强度极限分别为802.59±15.24 MPa和36.45±1.87 MPa,电导率为2.9570×10-3±1.7570×10-5 S·mm-1。载药PA纳米纤维和载药PA/CNTs复合纳米纤维都具有药物缓释性能,后者比前者的药物缓释能力更好。PA纳米纤维膜对大肠杆菌没有抑菌性,固体培养基中不同载药浓度的载药PA/CNTs复合纳米纤维随着载药量的增大对大肠杆菌抑菌效果越明显。液体培养基中的载药PA/CNTs复合纳米纤维对大肠杆菌的生长有抑制作用,且载药量越大抑制作用越明显。MTT测试结果和L929细胞粘附、增殖的SEM照片可知,PA纳米纤维、载药PA纳米纤维、载药PA/CNTs复合纳米纤维均没有细胞毒性,有利于成纤维细胞的粘附和增殖。该导电复合纳米纤维在神经组织修复和引导神经组织再生方面有潜在的应用价值。
[Abstract]:Nanotechnology has developed rapidly and the electrostatic spinning technology is used as a simple, fast and convenient preparation method of the nanometer material, and is widely used for preparing a wide variety of nano materials. In the field of biomedical engineering, the technique is used to prepare various biomimetic materials for the treatment, repair or replacement of tissue or organs of a human body. Polyamide (PA) has a number of polar organic amine groups (--CO--NH--) in the molecular structure, which can provide a friendly interface for cells and biological tissues, and has good cell compatibility. The PA nano-fiber was prepared by electrospinning using the formic acid solution of PA, and the main electrospinning parameters, such as voltage, receiving distance, humidity, temperature, etc., and the influence of the parameters of the solution, such as concentration and the like on the micro-morphology and diameter of the PA nano-fiber, were explored. The carbon nano-tube (CNTs) is a coaxial circular tube of several layers composed of six carbon atoms, and its unique physical and chemical properties make it have good biocompatibility, mechanical properties and electrical conductivity, so that it has wide application in the field of biomedicine. The effect of CNTs on the properties of composite fiber was investigated. and the drug model is used for preparing the drug-carrying PA nano-fiber and the drug-carrying PA/ CNTs composite nano-fiber. The micro-morphology of the nano-fiber is observed by scanning electron microscope (SEM), the mechanical property of the nano-fiber membrane is tested by the universal material testing machine, and the conductivity of the nano-fiber membrane in the wet state is tested by the four-probe test board; the distribution of the loaded drug is tested by an energy dispersive spectrometer (EDS), the drug release test of the in-vitro drug release test is used for testing the drug sustained-release performance of the drug-carrying nano-fiber, the culture of the solid and the liquid culture medium, and the antibacterial property of the drug-carrying nano-fiber on the Escherichia coli; The mouse fibroblast (L929) was inoculated on the nanofiber membrane to test its biocompatibility. The results show that, with the increase of the concentration of PA and the voltage, the diameter of the fiber increases, and the adhesion is reduced when the concentration is increased. As the receiving distance increases, the fiber diameter tends to decrease. When the air humidity is large, the diameter of the fiber is fine, but small micro-spheres appear, and the adhesion between the fibers is severe. When the ambient temperature is relatively high (45.degree. C.), the morphology of the fibers is good, and when the comparison is low (30.degree. C.), the composite of the fibers and the microspheres will be present. The concentration of the formic acid solution of the PA is 12wt%, the voltage is 18k V, the receiving distance is 12 cm, the temperature is 45 DEG C and the humidity is 16%, the appearance of the fiber is relatively good. The influence of CNTs on the morphology of the composite fiber is not obvious, but the mechanical property of the PA/ CNTs composite nano-fiber is obviously enhanced, and the increase of the content of the CNTs can lead the diameter of the PA/ CNTs composite nano-fiber to be reduced and the electric conductivity is enhanced. When the content of CNTs is 0. 9wt%, the elastic modulus and strength limit of the PA/ CNTs composite nano-fiber membrane are 802.59-15.24MPa and 36.45-1.87MPa, and the conductivity is 2.9570-10-3-1. 7570-10-5 S 路 mm-1. The drug-carrying PA nano-fiber and the drug-carrier PA/ CNTs composite nano-fiber have the drug sustained-release property, and the latter is better than the drug sustained-release capacity of the former. The PA/ CNTs composite nano-fiber with different drug-carrier concentration in solid culture medium has no antibacterial effect on Escherichia coli, and the more obvious the antibacterial effect of the PA/ CNTs composite nano-fiber on the E. coli as the drug-carrying amount is increased. The drug-carrying PA/ CNTs composite nano-fiber in the liquid culture medium has an inhibitory effect on the growth of E. coli, and the more the drug-carrying amount is, the more obvious the inhibition effect. The results of the MTT test and the adhesion and proliferation of the L929 cells showed that the PA nano-fiber, the drug-carrying PA nano-fiber, the drug-carrying PA/ CNTs composite nano-fiber had no cytotoxicity, and the adhesion and the proliferation of the fibroblasts were facilitated. The conductive composite nano-fiber has potential application value in the repair and guidance of nerve tissue regeneration.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.08

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