新技术帮助科学家在骨髓中寻找干细胞

Deep within the bone marrow¹ resides a type of cells known as mesenchymal stem cells (MSCs). These immature² cells can differentiate³ into cells that produce bone, cartilage, fat, or muscle -- a trait that scientists have tried to exploit for tissue repair. In a new study that should make it easier to develop such stem-cell-based therapies, a team of researchers from MIT and the Singapore-MIT Alliance in Research and Technology (SMART) has identified three physical characteristics of MSCs that can distinguish them from other immature cells found in the bone marrow. Based on this information, they plan to create devices that could rapidly isolate⁴ MSCs, making it easier to generate enough stem cells to treat patients.   Until now, there has been no good way to separate MSCs from bone marrow cells that have already begun to differentiate into other cell types, but share the same molecules⁵ on the cell surface. This may be one reason why research results vary among labs, and why stem-cell treatments now in clinical trials are not as effective as they could be, says Krystyn Van Vliet, an MIT associate professor of materials science and engineering and biological engineering and a senior author of the paper, which appears in the Proceedings⁶ of the National Academy of Sciences this week.   "Some of the cells that you're putting in and calling stem cells are producing a beneficial therapeutic⁷ outcome, but many of the cells that you're putting in are not," Van Vliet says. "Our approach provides a way to purify or highly enrich for the stem cells in that population. You can now find the needles in the haystack and use them for human therapy."   Lead authors of the paper are W.C. Lee, a former graduate student at the National University of Singapore and SMART, and Hui Shi, a former SMART postdoc. Other authors are Jongyoon Han, an MIT professor of electrical engineering and biological engineering, SMART researchers Zhiyong Poon, L.M. Nyan, and Tanwi Kaushik, and National University of Singapore faculty⁸ members G.V. Shivashankar, J.K.Y. Chan, and C.T. Lim.