Abstract: With the development of transgenic technology, it has become one of promising biotechnology to produce valuable pharmaceutical proteins using mammalian mammary gland as a bioreactor. Mammary gland bioreactors offer a high-yield，low-cost way to produce bioactive commercial pharmaceutical proteins that can not be produced efficiently by other methods and initiate a new approach for genetic engineering pharmaceutics. Recombinant human proteins produced by the mammary glands of genetically modified transgenic mammals have shown great commercialization prospects. So far, more than one hundred recombinant proteins have been successfully expressed in mammalian gland bioreactors, about thirty of which are in different phases of clinical trials. Antithrombin Ⅲ (ATryn^R), the first protein for human of antithrombin deficiency. Here, the principles, advantages, research advances and industrialization process of mammary gland bioreactors were reviewed and problems and strategies for protein production were also discussed.

Key words: transgenic animals; mammary gland bioreactor; recombinant protein; pluripotent stem cell