| Some metabolic diseases can be treated by oral administration of microencapsulated microorganisms that express specified enzyme. Generally, mass of microorganisms in gastrointestinal tract may evoke immunoreactions in human, and be damaged by the chemical or biological environment of alimentary canal. Once encapsulated, the bacteria inside the microcapsules are prevented from coming into contact with external environment like leucocytes, antibodies or enzymes. However, if the microorganisms leak from the microcapsules and generate in intestine, they will break the balance of microbial population in gastrointestinal tract, and it is possible to cause harm to the health. There are researches on how to enhance the strength of microcapsules at present; however, the desired results haven’t been achieved.To solve the problem, non-growing strain were studied in the research. In the article, the recombinant E.coli BL21 (DE3) strain UO20 that express urate oxidase was used as a sample. The urate oxidase was induced to express intracellular by fermentation. And the UO20 cells ware inactivated by formaldehyde. So, we got the non-growing recombinant E.coli cells that have the ability to reduce uric acid. The non-growing recombinant cells were encapsulated in alginate/chitosan/alginate (ACA) microcapsules with a micro-airflow-nozzle, and the related parameters in preparation were considerated. It is demonstrated that the microcapsules which was fabricated have the ability to reduce uric acid in vitro. The model of hyperuricacidemia was established by intraperitoneal injection of hypoxanthine to mouse. The in vivo effect of microencapsulated non-growing recombinant cells was tested by the model. Furthermore, the microcapsules were kept by freeze drying, and the stability was studied in different conditions and protective agents. We have laid a foundation for oral administration of the microcapsules, which provide reference on other metabolism therapeutical agents of microorganism. |
PDF Full Text Request