This is part one of a new weekly series focusing on recent advancements in the field of regenerative medicine.
The field of tissue engineering and regenerative medicine
Tissue engineering and regenerative medicine (TERM) is a large and rapidly growing field that has implications for the field of longevity. Broadly, the field of TERM is working towards regenerating tissues for which the only current options are replacement through organ donations, autografts, or artificial materials, and the ability to manufacture tissues would dramatically increase their availability to patients. TERM as a field is targeting every type of tissue in the body, but individual lines of research focus on single tissues at a time, which is unlike typical longevity research.
While the potential to replace every tissue and organ in the body at will has obvious implications for longevity, that objective is an absolutely monumental task for a field that, while promising, is still unproven. Additionally, much of what we consider the self is housed in the brain – an organ that ages just like every other tissue in the body and cannot simply be replaced as a whole.
While this field is being applied to a wide range of diseases, current TERM treatments generally have many limitations in common. Most importantly for longevity, these treatments are not tolerated well in the elderly. Simpler cell therapies struggle to provide benefits when transplanted into an environment already damaged by age. Organ transplants, which are more complex, are extremely invasive procedures that are more difficult to recover from the older you are. Furthermore, an old organ transplanted into a young person may last decades longer than it would have otherwise, but a young organ transplanted into an older person will eventually catch up to the rest of its new body. The ultimate ceiling of TERM treatments is still likely limited by aging.
Common ground with longevity
Of course, this is not to say there is no place for TERM in longevity. It is still a radically different approach to medicine with the potential to add years to general human healthspan and decades for the individual patients who benefit the most. Regeneration is a key objective for both fields, of course, and much of what TERM researchers learn can be applied by longevity researchers and vice versa. The two are also highly complementary. Different tissues age at different rates for different individuals [1], and targeting the regeneration of specific tissues may prove to be beneficial, depending on the scenario.
There are also labs, researchers, and companies that straddle the line between both fields. Heart attack, osteoarthritis, chronic kidney disease, sarcopenia, and many other conditions are key targets of both fields [2]. While the thymus is a key focus of some longevity-focused organizations, many other researchers are also trying to regenerate it using TERM technologies [3]. Organ-on-a-chip technology can be used to test drug safety and effectiveness more cheaply, more quickly, and potentially more accurately than in animal models. This technology is being developed primarily by TERM researchers, but it will have major implications for longevity research, as the time it takes to conduct aging experiments is a crucial limiting factor [4]. In a way, TERM is similar to gene therapy, immunotherapy, and artificial intelligence: their relevance to longevity depends on how they are applied.
Conclusion
The field of TERM aims to regenerate specific tissues and organs. While most, although not all, of these strategies do not modify aging, many of them overlap with longevity due to the various common objectives of the two fields. The knowledge and technologies developed by both fields are also highly complementary and can be applied to advance one another. In the coming weeks, we will zoom in on promising TERM strategies every Wednesday, highlighting promising developments in the regeneration of various tissues.
Literature
[1] Chhetri, J. K., Barreto, P. D. S., Fougère, B., Rolland, Y., Vellas, B., Cesari, M. (2018). Chronic inflammation and sarcopenia: A regenerative cell therapy perspective. Experimental Gerontology, 103, 115-123.
[2] Ahadi, S., Zhou, W., Rose, S. M. S., Sailani, M. R., Contrepois, K., Avina, M., … & Snyder, M. (2020). Personal aging markers and ageotypes revealed by deep longitudinal profiling. Nature Medicine, 26(1), 83-90.
[3] Tajima, A., Pradhan, I., Geng, X., Massimo, T., Fan, Y. (2019). Construction of thymus organoids from decellularized thymus scaffolds. Methods in Molecular Biology, 1576, 33-42.
[4] Ramadan, Q., Zourob, M. (2020). Organ-on-a-chip engineering: Toward bridging the gap between lab and industry. Biomicrofluidics, 14(4), 041501.
