There has been an increase in demand for organ transplantation in recent years, with more people suffering from severe health issues that lead to vital organ failure. However, due to various administrative hurdles, religious beliefs, and false perceptions about organ donation, not enough organs are available to meet the demand.
The world is experiencing a series of organ shortage crises, and as a result, scientists are looking at other ways to meet the demand for organ transplantation.¹
Regenerative medicine is one of the most exciting and innovative of these alternate methods for transplantation. The following includes critical aspects of regenerative medicine and the implications and potentially transformative benefits of using this form of medical practice to assist with organ transplantation.
Before exploring the origins and applications of this field, it’s useful to look at the history of regenerative medicine.
The idea of the body’s cells having a regenerative capacity is an ancient one. The Greek legend of Titan Prometheus incorporates this concept. After his liver was picked apart by the eagle Ethon as punishment for disobeying Zeus, this organ grew back again every night. The Greeks themselves seemed to be mindful of the liver’s reconstructing function.²
In the mid-18th century, the French chemist Antoine Lavoisier produced the groundbreaking hypothesis that scientists could replicate and research biological bodily processes in the laboratory.³ His research was built upon Descartes’ previous assertion that the human body operated not by some divine will but due to internal, complementary, chemical processes.
In the early 1900s, surgeon Alexis Carrel managed to develop and maintain a cell culture from some heart muscle of a young chicken. The culture seemed to possess remarkable regenerative qualities, surviving far longer than a regular chicken would.
By the beginning of the 1970s, scientists had discovered that specialist primordial germ cells (PGCs) in our body could create different reproductive cells or gametes. These gametes then develop into tissues and mature cells that can sustain and support a human.⁴
The discovery of these PGCs led to the eventual generation of both embryonic stem cell and embryonic germ cell (EGC) cultures in laboratories. EGCs are types of pluripotent stem cells with long-term regenerative capacities. They can differentiate into cellular aggregates called embryoid bodies, which create microtissues that can repair damaged body parts.⁵
Regenerative medicine is a major interdisciplinary field of study that works to reestablish contaminated or diseased tissues’ functioning ability. It is also one of the most appealing alternative forms of alleviating organ failure.
Another name for regenerative medicine is stem cell therapy. Stem cells are the building blocks scientists use to help develop specialized and healthy tissue to help repair organs.
Scientists take stem cells from healthy human tissues, most commonly bone marrow, blood vessels, the amniotic membrane, and even specific organs. They then hold this initial group of cells in a controlled laboratory environment, causing the cells to create specialized daughter cells. Some of these daughter cells differentiate into specific, functional cells, whether for the heart muscle, brain tissue, or bone marrow.
Because of both their unique regenerative capacity and their ability to specialize into different types of cellular tissue, stem cells hold the key for a new, sustainable form of organ repair.
There are several ways in which current regenerative medical practice can work to treat and repair diseased or dysfunctional organs.
In 2006, the scientist Mark Shackleton and his team created a culture of secretory mammary glands inside an adult mouse’s fat-pad. They did this by extracting one stem cell from the mouse’s mammary gland and moving it to the fat-pad.⁶ ⁷
Two years later, Kevin Leong and his team extracted one stem cell from a mouse’s prostate and transplanted it in vivo to create a whole new, fully operative prostate.⁸
These groundbreaking discoveries point toward the fact that scientists may be able to create and transplant properly functioning human organs in the future.
Decellularization is the process by which scientists strip the macromolecular extracellular matrix (ECM) or a tissue or organ down to its biological scaffolding. Once they’ve isolated this scaffolding, scientists can recellularize and repopulate the ECM with suitable stem cell populations.
The advantage of this method is that the macromolecular scaffolding provides the perfect stabilizing structure within which to generate a new organ or tissue.
Paolo Machiarini and his team performed a successful human trachea transplant by this method in 2008, using a donor trachea for the ECM scaffolding.⁹
Since then, various teams of scientists have successfully decellularized and regrown livers, lungs, and blood vessels.
In 1993, scientists discovered the blastocyst complementation system of organ generation.¹⁰ The original purpose of this method was to generate chimeric animals with multiple specialized organs that could function perfectly well in different animal species. A chimeric animal is one that contains cells with two different genotypes. The scientists used pluripotent stem cells to create this chimera, which in turn allowed for the generation of various new rat organs.
Again, this form of chimeric embryo generation could lead to significant advances in organ repair and production.
It’s an exciting time to be involved in regenerative medicine. Scientists in the field are on the verge of discovering innovative ways to generate and repair organs. Several cutting-edge methods are leading the way.
Tissue engineering is a method that integrates research from both the bioengineering and cell biology fields. Scientists extract cells from the patient and create pluripotent cells in vitro, which differentiate to form specialized organ cells. The scientists pick the suitable specialist cell culture before injecting them into the patient’s damaged organ.
So far, scientists have successfully produced bio-engineered bladders, tracheas, livers, and ovaries. These experts have also refined a dermatological cellular structure to use as artificial skin.
Researchers have discovered vital new information on the cell signaling pathways that influence proper kidney growth in the last few years. There is plenty of potential for future breakthroughs in tissue engineering.
In this form of therapy, scientists extract healthy stem cells from a donor and then inject them into a patient.
In 2009, preliminary research demonstrated that embryonic stem cells could be effectively transplanted into an animal’s spinal cord, allowing them to move again after severe injury.¹¹
This method has the potential to revolutionize the field of organ transplantation and generation. Neural and mesenchymal stem cells can help to regenerate the body’s nervous system and bone marrow. At the same time, research shows that individual stem cells could help to regenerate damaged heart tissue.¹²
One of the most significant advantages of this type of therapy is that scientists can use it to help patients who cannot withstand the process of full organ transplantation. It also requires less commitment from donors since tissue extraction tends to be less invasive than an organ allograft.
BioStem Technologies creates specialized VENDAJE allografts that you apply to wounds to help with tissue regeneration.
Continued growth in the field of regenerative medicine is opening new and exciting doors for organ generation and transplantation. From decellularization to cell therapy, single adult cell generation to the blastocyst complementation system, the regenerative medicine field produces many substantiated, fresh alternatives to standard organ donation.
If you work in the regenerative medicine field or are considering moving into this area of research, you should feel inspired by the transformative potential of stem cell therapy and organ generation. With further study and extensive laboratory tests, this medical practice could help solve the current organ shortage crisis.
(1) Abouna GM. “Organ Shortage Crisis: Problems and Possible Solutions,” National Library of Medicine, Transplant Proc., Jan-Feb 2008, https://pubmed.ncbi.nlm.nih.gov/18261540/
(2) Polykandriotis, E et al, “Regenerative Medicine: Then and Now--an Update of Recent History into Future Possibilities,” US National Library of Medicine, Journal of Cellular and Molecular Medicine vol. 14,10, 2010, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3823153/
(3) Polykandriotis, “Regenerative Medicine”
(4) Heany, Jason, “Germ Cell Pluripotency, Premature Differentiation and Susceptibility to Testicular Teratomas in Mice,” The Company of Biologists, Development, 2012, https://dev.biologists.org/content/139/9/1577
(5) Lin, Yonshun and Chen, Guokai, “Embryoid Body Formation from Human Pluripotent Stem Cells in Chemically Defined E8 Media,” NCBI, 2014, https://www.ncbi.nlm.nih.gov/books/NBK424234/
(6) Shackleton, Mark, “Generation of a Functional Mammary Gland from a Single Stem Cell,” US National Library of Medicine, Nature, 2006, https://pubmed.ncbi.nlm.nih.gov/16397499/
(7) Jain, Aditya, and Bansal, Ramta, “Applications of Regenerative Medicine in Organ Transplantation,” US National Library of Medicine, 2015, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4517320/#ref17
(8) Leong, Kevin, “Generation of a Prostate from a Single Adult Stem Cell,” US National Library of Medicine, Nature, 2008, https://pubmed.ncbi.nlm.nih.gov/18946470/
(9) Macchiarini, Paolo, “Clinical Transplantation of a Tissue-Engineered Airway,” US National Library of Medicine, Lancet, 2008, https://pubmed.ncbi.nlm.nih.gov/19022496/
(10) Chen, J, “RAG-2-Deficient Blastocyst Complementation: an Assay of Gene Function in Lymphocyte Development,” US National Library of Medicine, Proc Natl Acad Sci USA, 1993, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC46545/
(11) Keirstead, Hans, “Human Embryonic Stem Cell-Derived Oligodendrocyte Progenitor Cell Transplants Remyelinate and Restore Locomotion after Spinal Cord Injury,” US National Library of Medicine, 2005, https://pubmed.ncbi.nlm.nih.gov/15888645/
(12) Malliaras, Konstantinos and Marbán, Eduardo, “Cardiac Cell Therapy: Where We've Been, Where We Are, and Where We Should be Headed,” US National Library of Medicine, 2011, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3149211/