The dog bladder tissue has  successfully been regenerated by two Chinese scientists who  transplanted the bladder cells into a naked mouse.

   Experts say this marks another big breakthrough in the field of tissue engineering made by Wang Changyong and Fan Ming, two  researchers with Beijing-based China's Military Medical Research  Institute (MMRI), who had previously regenerated several types of  cartilage tissues.

   They first managed to take smooth muscle cells and epithelial  cells from a dog bladder, which were cultivated in vitro for some  time before being transplanted to a bladder-shaped support bracket made of special biological materials.

   Having grown large enough, the mixed tissue body was  transplanted into the back of a naked mouse through surgery. It  has expanded fast as the cells keep absorbing nutrition from the  mouse.

   Though carrying a "dog bladder" as big as half a ping-pong ball, the naked mouse still runs around and looks very robust.

   Tissue engineering is dedicated to the production and  regeneration of human tissues, which will enable people to clone  human tissues and turn the non-self tissue transplant into reality.

   The MMRI has made remarkable progress in the study of tissue  engineering, and is expected to come up with a series of  applicable products such as cartilage and bone tissues in the  coming years.

   China has established a human tissues research and development  in Shanghai early this year, which is the largest of its kind  worldwide, sources said.