The biggest hurdle remaining to the creation of viable, commercialized embryonic or adult stem cells is to develop the ability to differentiate cells into various types of cells and to determine how these differentiated cells behave when cultivated in large numbers in the laboratory. In many cases, researchers are still uncertain whether the cells retain their characteristics over time or if they will degenerate into a different or earlier version of a cell. For instance, it is unknown whether stem cells halt differentiation upon intravenous administration or if they will continue to differentiate as designed. While isolated instances of successful regeneration or repair have been reported, the task remains to replicate these successful therapies on a large scale.
Researchers have come to realize that cells cannot simply be laid out in a designed pattern and expected to grow into functional tissue. This is because the cells need specific structural, mechanical and chemical cues to guide cell morphology, migration and proliferation, to regulate cell differentiation, and to modulate cellular processes.
Research and development in this field is expensive; the burn rate is frequently $25 million–$40 million per year, with years of research and testing required before market launch, if indeed that is ever achieved. More than one company has had to declare bankruptcy and either close the doors for good, or reorganize and attempt to find additional funding (Advanced Tissue Sciences, Algenix, Artecel, Cell Based Delivery, to name a few), or sell its assets to another company before making its big breakthrough.
Once a technological breakthrough has been achieved, the company then faces the costs and uncertainties associated with regulatory hurdles, primarily clinical testing. If and when the clinical trials proceed with positive results and market launch appears possible, then the company needs to hire and train a sales force, or must make the strategic decision to give away part of the potential winnings by forming an alliance with a medical device or pharmaceutical company that has the sales network already in place. Also, before launch, the company must prepare to gear up its manufacturing capabilities, again meeting stringent good manufacturing requirements as required in the country of manufacture. Other tasks yet to be completed include acquisition of resources, acquisition of regulatory marketing approval.
From "Tissue Engineering, Cell Therapy and Transplantation, 2009-2018", February 2010; Report #S520.