One of the drawbacks of adult stem cells is that they have proved hard to "expand", or multiply, in the lab. Now MIT researchers have taken a step forward by using a cocktail of growth factors to increase the rate of multiplication by mouse bone marrow stem cells about 30-fold.

"One of the major issues for haematopoietic and bone marrow transplantation has been the inability to get sufficient numbers of cells because they just don't want to grow in the laboratory," Bruce Bunnell, of Tulane University, told HealthDayNews. "In general, we get maybe a two- to five-fold expansion, and for most patients and most transplants you need many more cells. The ability to generate many more cells would more than likely significantly enhance the efficiency at which engraftment occurs. The ability to go from five- fold to 30-fold is a tremendous advancement."

Experiments like this could lead to important advances in stem cell medicine. It would increase the efficiency of existing bone marrow transplants. And a larger number of cells could help gene therapy work consistently, leading to cures for some diseases.