Stem Cells from Knee Fat Become Bone and Fat Cells

Adult stem cells taken from knee fat have been turned into cartilage, bone, and fat cells by researchers at Duke University Medical Center (Durham, NC, USA). The resulting cells have the potential to be grown into tissue that could be used to repair or replace diseased or damaged tissue.

The researchers took the fat pads from patients whose knee joints were removed during total joint replacement surgery and focused on adipose-derived stromal cells that normally would transform themselves into fat pad cells. After the samples were treated with enzymes and centrifuged, the separated stromal cells were treated with a cocktail of steroids and growth factors. By controlling their biochemical environment and controlling their shape in a 3-D matrix, the researchers were able to grow different cell types from the stem cells. To grow cartilage, groups of cells were infused into a matrix made of alginate, which is often used as the basis for bioabsorbable dressings.

The fat pad is a dense structure behind the kneecap that is different from the typical fat found throughout the body. Although its function is not understood, it is known to be metabolized much more slowly than subcutaneous fat.

"By treating these stromal cells with different agents, we were able to induce them to commit to multiple lineages,” said M. Quinn Wickham, a medical student at Duke who presented the research results at the annual meeting of the Orthopedic Research Society in Dallas (TX, USA). "These findings suggest that the fat pad, give its location and accessibility, may prove to be an excellent source of progenitor cells for tissue engineering or other cell-based therapies.”