Despite the ongoing challenges we have described, engineered tissues are no longer a fantastical prospect. Simple manufactured tissues are already in clinical use, and this method of restoring or replacing biological function is now poised to become a viable therapy for millions of patients in need. As of late 2008, various tissueengineered products generated annual sales of nearly $1.5 billion.
Those figures are all the more impressive in light of setbacks to the field that occurred shortly after we last wrote for this magazine about the promise of tissue engineering. At the end of the 1990s and into the early 2000s, enthusiasm and investment were high, but with the burst of the Internet financial bubble, funding for biotechnology start-ups dwindled. Even companies with tissue-engineered products approved by the Food and Drug Administration had to restructure their business models, delaying introduction of their products to the market. Because engineered tissues are made from cells, biologically active chemicals and nonbiological scaffold materials, the constructs must undergo rigorous analysis by the FDA, which is costly and time-consuming. A lack of funding made conducting extensive clinical trials more difficult for companies. Ironically, the delay in commercializing some tissueengineered products had an upside—it bought time for the science to mature and for business approaches to become more sophisticated.
There is still room for improvement. Obtaining FDA approval is still a major hurdle, in part because cells obtained from different people may not behave alike and because recipients can have varying responses to the same kind of implant. Such unpredictability can make it difficult for the FDA to determine that a given engineered construct is safe and effective. Further research is therefore important to measure and understand variations between individuals and to account for them in clinical trials that study tissueengineered products. And future business models must include the extensive costs that will be associated with this work.
Still, armed with recent insights into how tissues develop and how the body repairs itself naturally, tissue engineers are now aiming to create second-generation products that are closer mechanically, chemically and functionally to their biological counterparts than ever before. Even in today’s strained economic climate, we expect that research into nanotechnology, stem cell biology, systems biology and tissue engineering will soon converge to yield fresh ideas for devising the sophisticated organ substitutes needed by so many people today.
Source of Information : Scientific American(2009-05)