One emerging strategy in medical research is to set up factories in the body to manufacture proteins and drugs in situ as needed. Taking advantage of existing cellular machinery to do this make sense, and so we see the production of technology demonstrations like this one:
The researchers inserted modified strands of messenger RNA into connective tissue stem cells - called mesenchymal stem cells - which stimulated the cells to produce adhesive surface proteins and secrete interleukin-10, an anti-inflammatory molecule. When injected into the bloodstream of a mouse, these modified human stem cells were able to target and stick to sites of inflammation and release biological agents that successfully reduced the swelling. "If you think of a cell as a drug factory, what we're doing is targeting cell-based, drug factories to damaged or diseased tissues, where the cells can produce drugs at high enough levels to have a therapeutic effect."
Mesenchymal stem cells have become cell therapy researchers' tool of choice because they can evade the immune system, and thus are safe to use even if they are derived from another person. [The messenger RNA] technique to program cells is harmless, as it does not modify the cells' genome, which can be a problem when DNA is used (via viruses) to manipulate gene expression. "This opens the door to thinking of messenger RNA transfection of cell populations as next generation therapeutics in the clinic, as they get around some of the delivery challenges that have been encountered with biological agents."