Stem cells are unspecialized cells with the ability to duplicate and differentiate. Unlike mature cells with a set purpose, stem cells are prompted into different functions based on need, such as tissue repair or growth. Because of this variability of stem cells, they are being used for treatments such as for Parkinson's disease or eye damage. Stem cells from the embryo, pluripotent stem cells, can be specialized for any function, while adult stem cell are generally multipotent and have a more limited range of functions. Stem cell therapy involves the use of stem cells to replace damaged or malfunctioning cells in order to treat certain conditions. Stem cells are collected from sources such as bone marrow and are implanted into the body through IV or injection.
CAR-T therapy:
CAR-T therapy targets cancers such as leukemia and lymphoma. T cells are collected from the body and then genetically modified to have a chimeric antigen receptor (CAR). These are designed to find certain antigens located on the surface of cancer cells so it can then bind to them. These CARs are implanted in the patient's extracted T cells in a lab. The CAR-T cells are then cultured and a population is grown and implanted back into the patient's bloodstream. The CAR-T cell recognizes the antigen on the cancer cells and binds to them, activating the CAR-T cell and killing the cancer cell. While the CAR-T therapy procedure has shown success in certain blood cancers and is thought to also minimize cancer reoccurence in the future as well, the other long-term side effects of the therapy have not been studied, and due to the therapy's personalized approach, it is complicated and costly as well.
Neural stem cell therapy:
Neural stem cell therapy uses neural stem cells to treat neurological disorders such as Alzheimers, damaged brain tissue from strokes, or traumatic brain injury. Similar to CAR-T therapy, the stem cells are collected, as well as cultured to create neural stem cells as needed. Then, these neural stem cells can be differentiated to wherever their purpose lies. For example, for one with a disease such as Parkinson's, where nerve cells in the brain lose function over time, these stem cells can be used to form new neurons or dopamine-producing neurons to stimulate healing and repair. Implanting these stem cells back into the body generally requires surgery in this type of stem cell therapy as the differentiated stem cells need to be implanted in specific regions in the brain for example to serve their intended purpose. Neural stem cell therapy is currently experimental and although there are cases of successes, it is not yet a completely safe option, as well as more research being needed to investigate long-term effects.
HSCT (Hematopoietic Stem Cell Transplantation):
Hematopoietic Stem Cell Transplantation uses blood-forming stem cells to treat conditions. In this form of stem cell therapy, the patient might be able to use their own stem cells, but more likely will be using another donor's stem cells extracted through bone marrow. The patient must undergo chemotherapy or radiation therapy before the HSCT can take place in order to make room for the donor's stem cells. When these stem cells are transplanted into the body, they produce new blood cells, which is a way to treat diseases affecting blood cells, such as lymphoma. The compatibility of the donor, the patient's health, the disease, and many other factors affect the success of this type of stem cell therapy however, and it is an extremely complex process.
Outlook:
Stem Cell Therapies are still in initial phases, which much more experimentation and data analysis to be done before it can be treated as a safe solution. However, its cases of success give hope into a new way of treating conditions previously thought to be incurable, and with more research into stem cell therapies, they may just be the cure.
References: "Answers to Your Questions about Stem Cell Research." Mayo Clinic, Mayo Foundation for Medical Education and Research, 19 Mar. 2022, www.mayoclinic.org/tests-procedures/bone-marrow-transplant/in-depth/stem-cells/art-20048117. "Car T Cells: Engineering Immune Cells to Treat Cancer." National Cancer Institute, www.cancer.gov/about-cancer/treatment/research/car-t-cells. Accessed 23 Sept. 2023. Lindvall OKokaia Z Stem cells for the treatment of neurological disorders. Nature 2006;441 (7097) 1094- 1096 Moore, Theodore. "Hematopoietic Stem Cell Transplantation (HSCT)." Practice Essentials, Historical Background, Indications for HSCT, Medscape, 13 Sept. 2023, emedicine.medscape.com/article/208954-overview.
