A look at what might be accomplished in the years ahead: "In work that could jumpstart the promising field of cell therapy, in which cells are transplanted into the body to treat a variety of diseases and tissue defects, researchers [have] engineered cells that could solve one of the key challenges associated with the procedure: control of the cells and their microenvironment following transplantation. ... the team reports creating tiny internal depots within human mesenchymal adult stem cells, which among other functions are key to the generation of several tissues. These depots can slowly release a variety of agents to influence the behavior of not only the cells containing the depots, but also those close to them and even much farther away. The team demonstrated this by prompting mesenchymal stem cells to differentiate into the cells that make bone. ... This work could allow programmable cell therapies where the cell or the agent is the therapeutic. For example, depots containing specific agents could enhance cell survival or expression of a particular growth factor. Cells could also be used as a delivery vehicle to shuttle drugs to target tissues that may be useful to accelerate tissue regeneration, or to deliver chemotherapeutics to tumors while minimizing systemic side effects. ... Ten to fifteen years from now, people will visit cell infusion centers to receive routine therapy for multiple diseases and tissue defects. ... For example, a person who has had a heart attack could be infused with cells that could help stimulate regeneration of new heart cells to replace those that have died and prevent eventual heart failure."