Abstract: Uremia is a very severe and wide spread disease, oral administration of microcapsulated genetically engineered E. coli is a better method for treating uremia than renal hemodialysis in terms of its high efficiency and low cost. In this paper, a new type of polyvinyl alcohol(PVA) microcapsules was prepared by using low temperature physical crosslinking method, which showed a strong mechanical strength, high chemical stability and low toxicity. Comparing with APA microcapsules that is currently used, PVA microcapsules has much higher mechanical strength. Moreover, the PVA microcapsules had a good permeability to small molecules such as urea, uric acid and creatitine, all of which can permeate through PVA microcapsules within 10 min. When the genetically engineered E. coli DH5 was entrapped to PVA microcapsules, the bacteria showed a high capacity for removal of urea, which was believed to be a key factor in the pathogenesis of uremia. Therefore, PVA microcapsules prepared by low temperature physical crosslinking method had a high potential for oral administration in the treatment of uremia patients.

Key words: Polyvinyl alcohol(PVA), Microcapsules, Low temperature physical crosslinking, Genetically engineered E. coli DH 5&alpha, cells