The field of regenerative medicine was considered science fiction when it started 25 years ago. However, lab-grown organs are now becoming a reality. A dream of replacing any non-functional organ with a brand new personalized counterpart can soon become true. In fact, many patients are currently walking around with artificial bladders, noses, ears and windpipes made in the lab from their own cells combined with tissue-supporting biomaterials. Researchers are now progressing to grow even more complex solid organs such as lungs, livers and kidneys for transplantation.
“It’s like making a cake,” said Alexander Seifalian, who is a professor at University College London, “We just use a different kind of oven.” In order to prepare personalized structures which are shaped and sized just like an original organ, researchers start the lab-grown organ recipe with a detailed analysis of the patient. Next, tissue engineers create a scaffold from donor organ by washing off its cells in a process called decellularisation. Then, the patient’s cells are planted on the scaffold which will support their growth.
However, a decrease in the number of transplantations has been observed recently. There is also continuous shortage of donor organs. Hence, researchers are pushed to develop cell-friendly artificial scaffolds. These scaffolds can be covered by patients’ cells, just like the decellularised donor organ. If the patients do not have enough cells of the right type, stem cells or progenitor cells can act as templates to grow more advanced cell types. However, they must be supported with right molecules and comfortable environment to direct them towards their desired fate. Once cells are seeded on the scaffold, the organ prototype is placed into the oven at the right temperature, oxygen concentration and food supply. Within weeks, custom-made organs will be ready to be transplanted into patients.
Although research groups all around the world are working to improve the recipe, there are still numerous roadblocks on the way. Organs are complex structures. In order to make their prototype as realistic as possible, the right proportion and arrangement of various cell types have to be conserved. Additionally, the human body tends to be very good at sensing and attacking foreign objects, and the transplanted organ is no exception. The best way to avoid an organ being attacked by the defence system is to find compatible biomaterial and, ideally, use patient- derived cells that will be recognised by the body.
When not transplanted, lab-grown organs (often in the form of miniaturized organs-on-chips) can be used to study development of diseases and test potential new treatments. Many pharmaceutical companies are already testing new products using miniaturised organs- on-chips. Biotechnology firms are also showing off their tiny versions of organs that increasingly resemble human body parts. In a recent study, a team of scientists has grown brain-like ‘organoids’ from cells of young patients with abnormally small brain, a disorder called microcephaly. This allowed them to unlock the biological mysteries of defective brain development and open the doors to drug discovery.
Even though promising results have been demonstrated by researchers who work along with clinicians, growing organs in the lab has not been mastered fully yet. Nonetheless, to the great advantage of the field, initial public scepticism has now subsided. It is replaced by optimism and hope in what lab-grown organs can offer to the severely ill. With the growing support for this rapidly developing field in this era of modern organ transplantation, it is exciting to see what the next 25 years ofregenerativemedicinewillbringtoour patients.
About the author:
Magdalena Plotczyk is a Master student in Nanotechnology & Regenerative Medicine at University College London. As a researcher, she enjoys challenging herself with problems in stem cell-based therapies, development of artificial organs and tissue engineering. During her Bachelor studies, she focused her efforts on the development of 3D model of skeletal muscle constructed from stem cells and biomaterials, now hoping to explore regeneration of other organ systems.