An intestinal bio-microreactor with potential application prospect as a drug delivery system was proposed and studied. It was designed to overcome the problems such as complexity of separation and purification, and su...An intestinal bio-microreactor with potential application prospect as a drug delivery system was proposed and studied. It was designed to overcome the problems such as complexity of separation and purification, and subsequent high costs, which always exist in producing genetically engineered drugs. For example, the process of separation and purification can be omitted by oral administration of genetically engineered microbes entrapped in semi-permeable membrane of microcapsules. The microencapsulated cells can live, metabolize and secrete therapeutic proteins in intestinal tract. In this paper, Pichia pastoris GS115 was selected as the model microbe, alginate-chitosan (AC) microcapsules as the carrier, and the physicochemical performance of the intestinal bio-microreactor was studied. It was found that the encapsulation efficiency of living yeast cells during the preparation of microcapsules was about 80%. It was shown that all AC microcapsules with yeast cells were kept intact in simulated gastric solution and simulated intestinal solution, and the survival of microencapsulated cells in simulated gastrointestinal solutions was 200-times higher than that of free cells, which showed that AC microcapsules can protect the activity of yeast cells. Furthermore, when being orally administered in mice, AC microcapsules could go through stomach and adhere to the surface of small intestinal mucous membrane over 12 h. Therefore, it was concluded that AC microencapsulated yeast cells could be used as intestinal bio-microreactor to secret bio-drugs in vivo directly.展开更多
氧气在微胶囊膜中的扩散行为将直接决定微囊内细胞的生长代谢行为。以海藻酸钠-壳聚糖聚电解质复合平板膜为研究模型,利用渗透池法,重点考察溶氧在膜中的扩散行为及其影响因素。结果显示:复合膜的扩散系数和孔隙率均低于海藻酸钙,复合...氧气在微胶囊膜中的扩散行为将直接决定微囊内细胞的生长代谢行为。以海藻酸钠-壳聚糖聚电解质复合平板膜为研究模型,利用渗透池法,重点考察溶氧在膜中的扩散行为及其影响因素。结果显示:复合膜的扩散系数和孔隙率均低于海藻酸钙,复合膜中溶氧扩散系数为(7～13)×10 10m2 s 1,为水中的23.3%～43.3%,孔隙率为93%～97%;扩散系数随海藻酸钠特性黏度的增大而减小,随壳聚糖分子量的增大而减小。微胶囊膜是氧传质主要的阻力部位,孔隙率、三维结构和材料极性是影响扩散性能的重要因素,改变海藻酸钠特性黏度和壳聚糖分子量可以改变膜孔隙率、结构和材料极性,进而调节膜扩散性能。展开更多
文摘An intestinal bio-microreactor with potential application prospect as a drug delivery system was proposed and studied. It was designed to overcome the problems such as complexity of separation and purification, and subsequent high costs, which always exist in producing genetically engineered drugs. For example, the process of separation and purification can be omitted by oral administration of genetically engineered microbes entrapped in semi-permeable membrane of microcapsules. The microencapsulated cells can live, metabolize and secrete therapeutic proteins in intestinal tract. In this paper, Pichia pastoris GS115 was selected as the model microbe, alginate-chitosan (AC) microcapsules as the carrier, and the physicochemical performance of the intestinal bio-microreactor was studied. It was found that the encapsulation efficiency of living yeast cells during the preparation of microcapsules was about 80%. It was shown that all AC microcapsules with yeast cells were kept intact in simulated gastric solution and simulated intestinal solution, and the survival of microencapsulated cells in simulated gastrointestinal solutions was 200-times higher than that of free cells, which showed that AC microcapsules can protect the activity of yeast cells. Furthermore, when being orally administered in mice, AC microcapsules could go through stomach and adhere to the surface of small intestinal mucous membrane over 12 h. Therefore, it was concluded that AC microencapsulated yeast cells could be used as intestinal bio-microreactor to secret bio-drugs in vivo directly.
文摘氧气在微胶囊膜中的扩散行为将直接决定微囊内细胞的生长代谢行为。以海藻酸钠-壳聚糖聚电解质复合平板膜为研究模型,利用渗透池法,重点考察溶氧在膜中的扩散行为及其影响因素。结果显示:复合膜的扩散系数和孔隙率均低于海藻酸钙,复合膜中溶氧扩散系数为(7～13)×10 10m2 s 1,为水中的23.3%～43.3%,孔隙率为93%～97%;扩散系数随海藻酸钠特性黏度的增大而减小,随壳聚糖分子量的增大而减小。微胶囊膜是氧传质主要的阻力部位,孔隙率、三维结构和材料极性是影响扩散性能的重要因素,改变海藻酸钠特性黏度和壳聚糖分子量可以改变膜孔隙率、结构和材料极性,进而调节膜扩散性能。
