A straightforward concept: replace defective cells
Cell therapy consists of grafting healthy cells where others are dead or do not function properly. While it is a very simple concept, it involves more complicated steps. First, find a source of cells to graft. Then, succeed in multiplying these cells to obtain an adequate stock of cells. And if necessary alter them genetically before grafting (ex vivo gene therapy).
Cells which are "different"
The cells being studied for this type of graft are stem cells found in embryos or certain adult tissues and induced pluripotent stem cells. The first have retained the ability to produce many different cell types whereas the second are reprogrammed to produce the desired cell type.
The challenge is to leave them some room to multiply while preventing them from proliferating like cancer cells. To prevent uncontrolled proliferation of these stem cells after grafting, they are often predifferentiated in vitro before being injected in vivo. Therefore, it is essential to know which "nutritional bath" is appropriate to direct specialisation towards the desired cell type...
An expanding field
Cell therapy requires many skills. Following some ethical and legislative issues concerning embryonic stem cells which slowed things down a bit, research is now moving forward almost everywhere in the world. There are numerous applications: epidermolysis bullosa, neuromuscular diseases, myocardial infarction, neurodegenerative diseases...