While the term “Regenerative Medicine” may be a new term in the course of medical history, the concept of the body fixing itself is not. The body’s ability to regenerate itself has been documented from ancient Greek legends to the early experiments of the Enlightenment. For thousands of years, humans knew organs like the liver were able to regenerate themselves. The process of how regeneration occurs would remain unknown for hundreds of years. In the 19th century, scientists were able to discover how the body operated through the unique activation of cells. This basic understanding of biology laid the groundwork for future experiments. One of the most important discoveries in the field of RM was the discovery of human stem cells in embryonic development.
In the 1960's Sir John Gurdon demonstrated the ability to repurpose stem cells into becoming more differentiated by regressing them into a previous state where they are more capable of changing into different cell types. One of the first stem cell research projects was conducted on a lab mouse in the 1980s. Scientists were able to extract embryonic stem cells from a mouse and conduct experiments on different genetic diseases. That stem cell experiment would pave the way for the first experiment of human embryonic stem cells. This later stem cell research focused on obtaining Vitro fertilization-derived embryonic stem cells from willing donations. Further breakthroughs would happen nearly 8 years later in the form of induced pluripotent stem cells (iPSCs). Shinya Yamanaka went above and beyond previous stem cell experiments when he was able to create the first iPSCs from adult skin cells. This breakthrough would eventually gain him a Nobel Prize.
More recently in the 20th century, the practice of organ transplantation was cutting edge. These original experiments were the precursor to the modern-day regenerative medicine practice called organogenesis. Scientists and doctors are now trying to use stem cells to create organs through the process of organogenesis. There are several ways to go about creating replacement organs for humans. One highly experimental process is called Xenotransplantation. Essentially transplanting a growing organ from a different species such as a pig into a human. These trials are still at the early stages and have several major obstacles to overcome. A more popular idea is to take induced pluripotent stem cells and create human organs in a more natural process. Humans already develop organs through human embryonic stem cells during early development. Scientists have conducted successful trials where they were able to conduct successful experiments creating organs both in vitro and in living animals from organ tissue cells. More recent experiments have offered some hope for the future of organ transplants.
Scientists and other professionals are conducting clinical trials on the application of human stem cells in health treatments under the University of Southern California. Out of the more than 10 different medical conditions they are researching, one group is looking into stem cell treatments for organ failure. While current technology limits the ability for complete organ generation, scientists are in the beginning stages of stem cell research. At USC, scientists are able to create the cellular filter found in kidneys called nephrons. At this level, scientists are able to successfully conduct experiments into common kidney issues. The stem cell-derived liver nephrons are also being used to help alleviate the discrepancy from donated kidneys and the exponentially high demand. Along with kidney replacement, the researchers are looking into a possible stem cell treatment for Alzheimer's disease, heart disease, and bone growth.
In the United States, stem cell research has been impacted by the legal environment. Different cell types are under unique legislation. For instance, in the United States, there are several laws restricting human embryonic stem cells in research. However, adult stem cells are used commonly in treatments and have no legal restrictions. Similarly, samples were taken from umbilical cord blood and amniotic fluid stem cells have proven to be incredibly potent and completely legal.