By Dulara Janani Kuruppu
The recent surge in research surrounding the field of regenerative medicine, or ‘tissue engineering’, marks a new dawn in the history of medical discoveries, promising treatments to match each patient’s unique medical requirements, and completely cure complications that have been only treated with medication up until recent years.
Regenerative medicine can be branched into three regions: stem cell treatment, 3D bioprinting, and exosome therapy. Each holds the potential to revolutionize modern medicine, enabling doctors to treat patients by renewing or regenerating damaged or dysfunctional tissue using the patient’s own cells, reducing the risk of tissue rejection and overcoming the challenge of taking immunosuppressant medication for the rest of the patient’s life.
Stem Cell Treatment
Stem cells are cells whose potency extends beyond that of most somatic cells (all body cells except germ cells) in the human body: stem cells can be either multipotent, pluripotent or totipotent, whereas differentiated cells are unipotent. Stem cells are unspecialized cells that can divide several times by mitosis, to then differentiate into several different cell types. This makes stem cells unique in that they allow for damaged cells to be replaced by functional ones.
Currently, hematopoietic stem cells are used to treat several blood disorders. Hematopoietic stem cells can be extracted from bone marrow or umbilical cord blood, and can differentiate into many blood components, including mature red blood cells, white blood cells and platelets. This enables doctors to use hematopoietic stem cells to treat blood cancers such as leukemia and lymphoma, and non-malignant diseases such as sickle cell disease.
However, stem cells may also be derived from the inner cell mass of a blastocyst, one of the early stages of an embryo, a source that has sparked much controversy since it was first researched by Dr. James Thomson and John Gearhart in 1988. Although the embryos used for research on embryonic stem cells (ESCs) are willingly donated by patients who have undergone IVF in fertility clinics, the debate surrounding the ethics of destroying embryos, a potential form of life, is ongoing. On the other hand, if further research into the capabilities of ESCs is sustained, its advocates hope that the pluripotency of these stem cells will drive many medical advances in the future.
Stem cells
3D Bioprinting
Since the inception of 3D printing in 1984, it has increasingly become clear that implementing such tools in the healthcare system could transform the lives of patients for the better.
There are many ways to approach bioprinting, but one of the most popular methods is extrusion-based bioprinting. This method is analogous to that of additive manufacturing, where the printer constructs an object, layer by layer. Likewise, bioink, which consists of live cells, hydrogels and growth factors (including collagen, alginate and other biopolymers) is squeezed through a nozzle that is guided by a digital blueprint created by X-rays or scans (MRI or CT scans) to form a tissue or organ.
To this day, bioprinters have been used to create bone, skin, cartilage and blood vessels by researchers in the field. A breakthrough was made when a bioprinted bladder, made using the stem cells of a young patient, was successfully transplanted to replace his defective organ in 2004. Luke Massella, who underwent the surgery when he was 10 years old, is now living an ordinary life, which would have been highly improbable prior to the transplantation surgery. The same group of researchers has also succeeded in seeding a scaffold to produce a viable urethra using bioprinting.
Although we have yet to make great progress in creating and transplanting more complex organs such as kidneys, livers and hearts that are viable and functional, scientists are hopeful that further research into bioprinting technologies will revolutionize regenerative medicine, bringing tailored organs with little to no risk of complications to patients.
Bioprinting
Exosome Therapy
Exosomes are nanoscopic vesicles that are produced by cells and facilitate cellular communication, containing growth factors, nucleic acids (DNA and RNA), proteins and various other metabolites. Primarily used in aesthetic medicine, the contents of exosomes are employed to promote elastin and collagen production to enhance the texture and appearance of skin.
The appeal of exosomes for dermatologists is heightened by their skin rejuvenating properties and the expedited healing time. Currently competing with other cosmetic treatments such as platelet-rich plasma (PRP) treatments, microneedling and laser therapy, the recent enthusiasm for exosome therapy may drive many significant discoveries into the benefits and potential of exosomes in the field.
Exosomes
References
“A New Bladder Made from My Cells Gave Me My Life Back.” 10 Sept. 2018
Caplan, Arnold I. “Tissue Engineering: Then, Now, and the Future.” Tissue Engineering. Part A, vol. 25, no. 7–8, Apr. 2019, p. 515
“Beyond Stem Cells, Regenerative Medicine Finds Exosomes.” Mayo Clinic Press, 24 Jan. 2022
Kalluri, Raghu, and Valerie S. LeBleu. “The Biology, Function, and Biomedical Applications of Exosomes.” Science (New York, N.Y.), vol. 367, no. 6478, Feb. 2020
Keane, Courtney. 3D Bioprinting. opentextbooks.clemson.edu
“Printing the Future: 3D Bioprinters and Their Uses.” Curious, 29 Feb. 2016
Pros and Cons | Stem Cells | University of Nebraska Medical Center
Rahman, Anjuman. “4 Medical Breakthroughs 3D Bioprinting Is Having in the Healthcare Industry.” NS Medical Devices
“Tissue Engineering and Regenerative Medicine.” National Institute of Biomedical Imaging and Bioengineering,
Comments