Stem Cell in Regenerative Medicine

Stem cell regenerative medicine is another name for Stem cell therapy. It is a rapidly innovative field of research studies which revolves around stem cells to repair, replace, or regenerate diseased or injured tissues and organs. This innovative area of medicine will be a remedy for organ transplantation by using stem cells instead of depending on donors for organs.

Types of Stem cells and their properties:

There are six types of stem cells, including embryonic stem cells (pluripotent), adult stem cells (multipotent), tissue specific progenitor stem cells (TSPSC), mesenchymal stem cells (MSC), umbilical cord stem cells (UCSC) and induced pluripotent stem cells (iPSCs). Each of them has the two important characteristics: the ability to make copies of themselves (self-renewal) and the potential to differentiate into different cell types.

Roles of Stem cells in medicines:

Stem cells can be treated to become specialized cells that can be brought into use to regenerate specific tissue types which have been diseased, damaged or injured.  This type of therapy can be used in insulin therapy for diabetes, cases of spinal cord injuries, heart disease, regeneration of intestinal tissues and restoration of vision.

Stem cells have also been proved useful for creating stem cell models of diseases to better understand their mechanisms of development and progression and further develop new treatments.

Further, stem cells are widely used to test the safety and efficacy of novel drugs. For example, stem cells are used to differentiate into heart, kidney, intestinal or liver cells which are further treated with various drugs to test their toxicity on these human cells.

Current Research and Treatments:

Currently, the only stem cell-based therapy that has been closely reviewed and approved by FDA Hematopoietic (blood). This type of stem cell transplantation is used to treat blood, immune system and bone marrow diseases.

Mesenchymal Stem Cells (MSCs) are being researched for their potential to treat conditions like osteoarthritis, cardiac ischemia, and bone related disease.

Studies on using stem cells for organ regeneration to grow entire organs or parts of organs for transplantation are now a very well-established medical field.  Patients using this modern therapy have benefitted from new organs like kidneys, hearts, lungs, pancreas, hearts etc.  This method has been successful and saved many lives.

Medical limitations, Ethical and Socio-economic issues:

There is always the risk of the body rejecting transplanted stem cells. This rejection takes place when the recipient sees the transplanted tissue as a foreign antigen and elicits a robust immune response which leads to complex immune reaction.

Various stem cells that are cultured in the lab have cancer causing oncogenes.  It has been about 19 years since researchers isolated stem cells from embryonic cells.  But it was not until the year 2011 that the scientists found the cancer-causing gene expressed in them.  When these type of stem cells are used for the treatment of other diseases including Parkinson’s, macular degeneration, and diabetes, potential stem cells can lead to the formation of tumors. Inappropriate stem cell migration has resulted in neurological problems and other disorders.

Ethical issues have surfaced particularly around the use of embryonic stem cells. Limited supply of organs has led to organ trafficking. Moreover, there have been controversies of the stem cells leading to human cloning, and development of human-animal chimeras.

Advances and Innovations:

Induced Pluripotent Stem Cells (iPSCs)

There have been ethical concerns raised over the usage of embryonic stem cells.  This has limited access and medica research for the scientists to find therapies using human embryonic stem cells. Recent research has developed novel methods to reprogram human somatic cells into pluripotent cells like embryonic stem cells.  This was done by the expression of four transcription factors in the somatic cells.  This finding will enable the ongoing research for stem cell therapy without using the embryonic stem cells collected from the embryo and will be able to overcome ethical issues related to embryonic stem cells.

Potential to correct genetic defects using gene editing techniques

Techniques like CRISPR-Cas9 allow precise editing of genetic regions that can lead to the repression or activation of the desired genes.  This may allow to correct any genetic defects at the stem cell level by manipulating the gene of interest.

3D Bioprinting

Various 3D bioprinting including inkjet bioprinting, laser-assisted bioprinting, scaffold-free spheroid-based bioprinting, microextrusion bioprinting etc. has been successfully employed using stem cells from various origins and potency. This type of technology can be promising to create different tissue structures (tissue engineering) and regeneration of organs.

Future Directions:

Ongoing extensive research and clinical trials will determine the safety and efficacy of various stem cell therapies. Besides new techniques are developed to integrate stem cell therapy with other treatments, such as gene therapy or immunotherapy. For the rapid and promising advancements in this field, development of guidelines and regulations are required to ensure the safe and ethical use of stem cell therapies.

Stem cell regenerative medicine is poised to transform treatment modalities by offering innovative solutions to some of the most life-threatening medical issues. Continued research and collaboration among scientists, clinicians, and policymakers are crucial to fully realize the potential of this cutting-edge field.

References:

Atala A, Lanza R (2012). Handbook of Stem Cells. Academic Press. p. 452. ISBN 978-0-12-385943-3.

Kimbrel EA, Lanza R (December 2016). "Pluripotent stem cells: the last 10 years". Regenerative Medicine. 11 (8): 831–847. doi:10.2217/rme-2016-0117

Mahla RS (2016). "Stem Cells Applications in Regenerative Medicine and Disease Therapeutics". International Journal of Cell Biology. 2016 (7): 1–24.

Müller AM, Huppertz S, Henschler R (July 2016). "Hematopoietic Stem Cells in Regenerative Medicine: Astray or on the Path?". Transfusion Medicine and Hemotherapy. 43 (4): 247–254.

Bernadine Healy, M.D.. "Why Embryonic Stem Cells are obsolete" US News and world report. Retrieved on Aug 17, 2015.

Lo, Bernard; Parham, Lindsay (May 2009). "Ethical Issues in Stem Cell Research". Endocrine Reviews. 30 (3). NIH: 204–213.

Hindley C, Philpott A (April 2013). "The cell cycle and pluripotency". The Biochemical Journal. 451 (2): 135–143.