基于单腔室微囊和三腔室微囊的研究应用
发布时间：2018-10-09 17:35
【摘要】：现阶段所报道固定生物催化剂的载体多是由层层自组装过程(LBL self-assembly)所制备的聚合物囊泡/微囊,这种纳、微米反应器适用一些简单的催化体系,对于一些更加复杂的或者含不相容元素的体系来说,具有一定的局限性。本课题组首次利用静电纺丝技术,制备具有中空结构的微囊,并成功用于多酶催化体系在其内腔室的原位封装。这种新型的固定多酶体系与传统纳、微球相比,其微米尺度的腔室可以为所包埋酶提供一个极其稳定的微环境;同时由于具有良好的分散性更有利于催化反应。本论文的研究主要包括以下几个部分;1.采用同轴电喷技术制备聚氨酯(Polyurethane,PU)中空微囊。考察内、外相电纺液的组成及掺杂聚合电解质对中空微囊形貌及内外径的影响。以含水量20φ%(v/v)甘油溶液作为内相电纺液,以溶于N,N二甲基乙酰胺(DMAC)的10 wt%聚氨酯溶液作为外相电纺液,内外相流速分别为0.05 mL/h和1.0 mL/h,电压为20 kV左右,针头到接收板距离为40 cm,温度为25℃,湿度为10%条件下,可以制备出结构均一的中空微囊。2.以南极假丝酵母脂肪酶(CALB)、葡萄糖氧化酶(GOD)和辣根过氧化物酶(HRP)作为模型反应,将其定位组装于中空微囊的内腔室、壁层和外表面,通过同轴电纺技术结合层层自组装和离子配对技术。研究结果显示,催化体系中封装在内腔室和吸附在外表面的单酶活性收率均保持在68%以上,掺杂在壁层的单酶活性收率同样保持在48%以上。定位组装催化体系的活性收率为28%,重复使用8次后活性仍保持在初始活性的70%,在60℃的半衰期比游离酶提高了 12倍。这种组装方法极大的提高催化体系的稳定性,并且具有操作简单、条件温和、容易制备等优点;同时通过这种组装方法简单调整溶液PH以及选择合适的表面活性剂,可以实现多酶催化体系以一种我们希望的反应次序定位组装于聚氨酯中空微囊上。3.通过设计特定的喷丝头以及同轴电喷参数的优化,制备三腔室中空微囊。将三酶体系的每种酶原位包埋于微囊的三个腔室,构建基于三腔室微囊的多酶催化体系。这是首次通过同轴电纺技术制备具有生物兼容性的三腔室微囊,它的性能通过级联反应的催化效率进行表征。此催化体系中单酶活性收率均保持在60%以上,多酶催化体系的活性收率保持在14.65%,级联反应的稳定性也获得极大的提高。这种可以实现空间分离的多腔室微囊,在固定三酶催化体系(CALB/GOD/HRP)的研究中并没有展现它结构上的优越性。它在两相体系或者含有不相容元素的多酶催化体系或许会能够展现它所特有的结构优势。
[Abstract]:At present, the carriers of immobilized biocatalysts are mostly polymer vesicles / microcapsules prepared by layer upon layer self-assembly process (LBL self-assembly). This nano-micron reactor is suitable for some simple catalytic systems. There are limitations to more complex or incompatible systems. For the first time, the microcapsules with hollow structure were prepared by electrostatic spinning technique, and successfully used in the in-situ encapsulation of multi-enzyme catalytic system in the inner chamber. Compared with the traditional nanospheres and microspheres, this new type of immobilized multi-enzyme system can provide an extremely stable microenvironment for the encapsulated enzymes, and it is more favorable for the catalytic reaction because of its good dispersity. The research of this thesis mainly includes the following parts. Polyurethane (Polyurethane,PU) hollow microcapsules were prepared by coaxial electrospray technique. The effects of the composition of external phase electrospun solution and doped polyelectrolyte on the morphology and inner diameter of hollow microcapsules were investigated. Water content 20 蠁% (v / v) glycerol solution was used as inner phase electrospinning solution, and 10 wt% polyurethane solution dissolved in N dimethyl acetamide (DMAC) was used as external phase electrospinning solution. The flow rate of internal and external phase was 0. 05 mL/h and 1. 0 mL/h, voltage was about 20 kV, respectively. When the distance from the needle to the receiving plate is 40 cm, the temperature is 25 鈩，
本文编号：2260177
[Abstract]:At present, the carriers of immobilized biocatalysts are mostly polymer vesicles / microcapsules prepared by layer upon layer self-assembly process (LBL self-assembly). This nano-micron reactor is suitable for some simple catalytic systems. There are limitations to more complex or incompatible systems. For the first time, the microcapsules with hollow structure were prepared by electrostatic spinning technique, and successfully used in the in-situ encapsulation of multi-enzyme catalytic system in the inner chamber. Compared with the traditional nanospheres and microspheres, this new type of immobilized multi-enzyme system can provide an extremely stable microenvironment for the encapsulated enzymes, and it is more favorable for the catalytic reaction because of its good dispersity. The research of this thesis mainly includes the following parts. Polyurethane (Polyurethane,PU) hollow microcapsules were prepared by coaxial electrospray technique. The effects of the composition of external phase electrospun solution and doped polyelectrolyte on the morphology and inner diameter of hollow microcapsules were investigated. Water content 20 蠁% (v / v) glycerol solution was used as inner phase electrospinning solution, and 10 wt% polyurethane solution dissolved in N dimethyl acetamide (DMAC) was used as external phase electrospinning solution. The flow rate of internal and external phase was 0. 05 mL/h and 1. 0 mL/h, voltage was about 20 kV, respectively. When the distance from the needle to the receiving plate is 40 cm, the temperature is 25 鈩，
本文编号：2260177
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