As researchers continue to uncover potential health and medical benefits associated with the regenerative properties of stem cells, there is growing interest in the field of stem cell medicine and specifically for use as an alternative therapeutic treatment of pain.
Of particular recent interest in this area is the differentiation ability of stem cells classified as totipotent, pluripotent, and multipotent. Stem cells that can differentiate into and form cells and build organs are known as totipotent stem cells. Pluripotent stem cells are able to differentiate into various types of cells. Multipotent stem cells can differentiate into several limited forms of cells. Of the three different types, only multipotent stem cells are found as adult cells in the body, including in organs, placenta, and bone marrow.
Recently, stem cell transplantation has been used as an alternative treatment for pain associated with severe osteoarthritis, neuropathic pain, and intractable musculoskeletal pain that does not respond to traditional or conventional medication.
Although stem cells are thought to be a potential treatment approach for repairing and regrowing cartilage required for treating severe osteoarthritis, to date, regeneration of damaged cartilage has proven to produce limited results. One of the significant issues associated with using stem cells to regenerate cartilage is that cartilage contains no blood vessels or nerves, making cartilage regenerations very difficult once it is damaged. Making the process even more difficult, cartilage regeneration can only occur when the entire layer of cartilage and the layer of bone directly below the cartilage is damaged.
As such, therapeutic stem cell treatment possibilities for osteoarthritis include individual or combination treatment(s) of surgical intervention, tissue engineering, and intra-articulation injection of cultured stem cells; of these possible treatment options, intra-articulation injection of cultured cell therapy would be the preferred method as it is the least minimally invasive and most convenient for clinical use.
There have been mixed reviews as to the effectiveness of these treatments and, to date, there have been no reliable and convincing clinical human students with a high level of evidence conducted specifically on the efficacy in functional improvements and cartilage repair surrounding the application of intra-articular stem cell injection therapy. Although some who have had this treatment expressed improvements.
Stem cells have demonstrated the ability to release neurotrophic factors that enhance the growth and survival potential of neurons, secrete anti-neuroinflammatory cytokines, and provides a cellular source for replacing injured neural cells; this makes the application of stem cells a prime option for regulating and potentially even reversing intractable neuropathic pain.
Studies have confirmed that relieving neuropathic pain is possible through the administering of stem cells, both through intravenous injection and when directly administered to a specific injured site. However, while stem cells do not need to make direct contact with injured cells to produce a neuroprotective effect, stem cells applied directly to an injured site, as opposed to those intravenously injected appeared to better target and relieve neuropathic pain associated with a specific area.
In addition, while a further clinical human study is required, animal models of both diabetic neuropathic pain and spinal cord injury demonstrate that stem cell therapy, and specifically mesenchymal stem cells (MSCs), demonstrated improved blood circulation and nerve conduction velocity, reduced pain, and regeneration of the affected nerve.
Intervertebral Disc Disease
Patients diagnosed with degenerative disc disease who were treated with MSCs injected directly into the nucleus pulposus, or inner core of the vertebral disc demonstrated a reduction in pain and disability comparable to spinal fusion surgery.
Research has yet to identify an adequate, effective dosage of stem cells and further research on specific stem cell type, dosage, safety, and implantation rate is required. As research into the use of stem cell therapy in pain medicine progresses, it is important to see the development of evidence-based standardized methods of treatment.
While still in the early stage of clinical application, the use of stem cells in the treatment of pain appears to be very promising.
Reference: (2019, October 1). Stem cell therapy in pain medicine – PubMed. Retrieved December 11, 2020, from https://pubmed.ncbi.nlm.nih.gov/31569916/