新型纳米细菌纤维素生物医用材料的制备及评价
发布时间：2018-10-25 12:52
【摘要】：细菌纤维素(Bacterial Cellulose, BC)是一类由微生物产生的纯纤维素。因其独特的物理、化学性质而赋予其极高的机械强度和生物相容性,是一种新型生物纳米材料,已广泛应用于食品、造纸、声音振动膜、石油开采以及环保、生物医学材料等各个领域,成为国内外研究的热点。细菌纤维素在医学材料上的应用研究主要集中在创伤敷料和人造血管等方面。 具有高附加值的生物医用敷料的开发已成为细菌纤维素研究的热点。纱布是传统创伤敷料,但由于其吸水性能差,保湿能力不足,载药能力差,换药时造成二次创伤等缺陷,限制了其在高档产品上的应用。另一方面,近来兴起的BC膜创伤敷料由于其生产效率低,生产成本高,力学性能差,使用不方便等不足,也限制了其的应用。本课题通过“亚动态”培养方式,原位合成BC/纱布复合材料。该复合材料兼具BC膜和纱布的两种材料的优点：一方面在纱布上均匀涂覆了一层具有超细网状结构细菌纤维素,可以改善纱布的吸水、保湿,载药性能,以及物理阻隔性能；另一方面将纱布作为支架引入BC膜中能够增强了BC膜的力学性能。同时由于“亚动态”培养方式是依据BC生产菌(木醋杆菌)生理习性设计,显著提高了BC的生产效率,因此这一技术为BC在创伤敷料上的生产应用开辟了新的思路。通过对BC/纱布复合材料的相关性质的表征,证明两种材料结合良好。本研究利用浸渍法将苯扎氯铵整合到BC/纱布复合材料上制备出抗菌膜,并比较了不同预处理方式对BC/纱布复合材料吸附苯扎氯铵的影响,以大肠杆菌和金黄色葡萄球菌作为模式菌,用生长曲线法和菌落计数法表征该抗菌膜的抑菌效果。 细菌纤维素本身不具有抗菌性能,只能通过复合纳米银或壳聚糖等抗菌剂来赋予BC敷料抗菌性能。目前这种复合主要是通过(1)后处理复合。该方式不但增加了工序,而且抑菌剂仅以简单物理吸附结合在BC膜上,达不到真正缓释和长久保护伤口的要求；(2)通过往发酵培养基中加入抑菌剂的方式。抑菌剂可能会抑制细菌的生长和细菌纤维素的合成。本课题利用“亚动态”培养方式,通过在木醋杆菌发酵过程中少量多次添加壳聚糖的方式,成功原位合成了壳聚糖/BC/纱布复合材料,并比较了6种不同壳聚糖的添加效果,其中水溶性壳聚糖的复合效果最好,并对6种壳聚糖/BC/纱布复合材料进行了衰减全反射红外测试表征,结果显示复合材料中有氨基,从一个方面证实了壳聚糖的存在；另外也比较了5种壳聚糖本身对大肠杆菌和金黄色葡萄球菌的抑菌作用。 寻找新型可代替的血管材料一直是世界研究热点。虽然目前大口径血管移植物在临床中已成功应用,但普通小口径人造血管的研究由于其易形成血栓而一直停滞不前。常见的医用人造血管材料一般为疏水性材料,表面自由能高,易于血浆蛋白发生相互作用,形成附壁血栓。细菌纤维素具有优良的生物相容性、无过敏反应和具有抗血栓性能,因而B C人工血管成为研究的热点。目前国内外主要以透氧硅胶管为介质采用静态培养的方法发酵制备,但是静态发酵周期长、材料会出现分层现象；而利用“亚动态”缠绕法培养的纤维素管表面的均匀性较差。为此,本课题在实验室现有“亚动态”缠绕法的基础上拟通过置换培养基和置换富氧培养基的方式改善BC管的匀度。针对纯BC管力学性能差和生产效率低,而纺织基小口径血管不具备抗血栓能力这一瓶颈,本课题提出在纺织基血管坯材上涂覆一层贯穿纺织基管坯材料的细菌纤维素抗凝血层的设想,并利用“亚动态”缠绕法对这一设想进行了初步尝试。首先通过在B C管中引入数根纤维支架作为简易模型验证设想的可行性,然后利用“亚动态”缠绕法和静态套管法进行了涂层血管初探,初步结果表明粘胶纤维复丝较涤纶单丝或涤纶复丝有利于BC的复合。
[Abstract]:Bacterial cellulose (BC) is a class of pure cellulose produced by microorganisms. Due to its unique physical and chemical properties, it has extremely high mechanical strength and biocompatibility, is a novel biological nano material, and has been widely applied in various fields such as food, paper making, sound vibrating membrane, petroleum exploitation and environmental protection, biomedical materials and the like, It has become the hot spot of research at home and abroad. The application of bacterial cellulose on medical material is mainly focused on wound dressing and artificial blood vessel. The development of bio-medical dressing with high added value has become the research of bacterial cellulose The gauze is a traditional wound dressing, but because of poor water absorption, insufficient moisture retention capacity, poor drug-carrying capacity and secondary trauma, it limits its application on high-grade products. On the other hand, because of the low production efficiency, high production cost, poor mechanical property, inconvenient use and the like due to low production efficiency, high production cost, poor mechanical property, inconvenient use, Application. In this project, BC/ gauze composite was synthesized in situ by 鈥渟ub-dynamic鈥，
本文编号：2293744
[Abstract]:Bacterial cellulose (BC) is a class of pure cellulose produced by microorganisms. Due to its unique physical and chemical properties, it has extremely high mechanical strength and biocompatibility, is a novel biological nano material, and has been widely applied in various fields such as food, paper making, sound vibrating membrane, petroleum exploitation and environmental protection, biomedical materials and the like, It has become the hot spot of research at home and abroad. The application of bacterial cellulose on medical material is mainly focused on wound dressing and artificial blood vessel. The development of bio-medical dressing with high added value has become the research of bacterial cellulose The gauze is a traditional wound dressing, but because of poor water absorption, insufficient moisture retention capacity, poor drug-carrying capacity and secondary trauma, it limits its application on high-grade products. On the other hand, because of the low production efficiency, high production cost, poor mechanical property, inconvenient use and the like due to low production efficiency, high production cost, poor mechanical property, inconvenient use, Application. In this project, BC/ gauze composite was synthesized in situ by 鈥渟ub-dynamic鈥，
本文编号：2293744
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