Archived — Canadian asset map for stem cell and regenerative medicine

Introduction


2.1 Importance of Regenerative Medicine and Stem Cell

Regenerative medicine involves the renewal of body tissues or the restoration of organ and tissue function through the use of living cells, particularly stem cells. Stem cells offer a particularly rich source of regenerative technologies as, under the right conditions, they can differentiate into many different cell types (see below). They have considerable potential to help in the treatment of numerous common and intractable diseases and conditions, such as diabetes, arthritis, stroke, renal failure, heart failure, cancer, spinal cord injury, and neurodegenerative diseases, including Parkinson's and Alzheimer's. They can also be used in organ regeneration, genetic diseases, and other tissue repair or replacement (e.g., bone and skin transplants, cartilage regeneration).

A number of stem cell-based regenerative technologies are used today, such as eye surface stem cells for the treatment of some corneal diseases and injuries; and blood stem cells for treating hematological cancers (e.g. leukemias) and other conditions, such as sickle cell anemia. In fact, bone marrow transplants have become a standard of care for the treatment of certain hematological cancers, while skin stem cells are frequently used in wound healing. However, these clinical uses represent just a small fraction of the opportunities in regenerative medicine and researchers are working furiously to understand the role stem cells may play in other diseases, and to translate these findings into the clinic.

To be clinically effective, stem cells need to be delivered to and integrate with the relevant body site. Delivery methods can include gels, films, scaffolds, and targeted carrier technologies that are produced from biomaterials (e.g., polymers, lipids), modified cells or, in the case of some carrier technologies, modified viruses. The combination of stem cells (or other cell types) and a scaffold or similar technology is called tissue engineering. Furthermore, because stem cells occur in highly limited quantities within the body, effective methods are required to mobilize, isolate, culture, and store them. Adequate production methods are essential to unlocking their clinical potential.

2.2 Purpose of the Asset Map

Using the methodology described in Appendix 1, this Asset Map provides a snapshot of Canadian stem cell and regenerative medicine research. Since this research sector could potentially be extremely broad-based, we have specifically focused on pluripotent, tissue-specific, and cancer stem cell research, biomaterials in terms of scaffolds or similar technologies for use in regenerative medicine, and tissue engineering in terms of production of stem cells and their delivery device. We have not included gene therapy (unless it involves stem cells) or growth factors, xeno-organs, regeneration of plants or animals (unless the studies relate to experimental models of human conditions) or companies working in regenerative medicine.

2.3 Description of Stem Cells

This Asset Map distinguishes between three overall types of stem cell. The two major stem cell types are pluripotent and tissue-specific (also known as adult or stromal). The third type of stem cell specifically targeted in this report are cancer stem cells, a type of tissue-specific cell.

Pluripotent stem cells have the ability to give rise to all kinds of cell in the body, such as those of the heart, lungs, muscles, skeleton, or brain. These unspecialized stem cells are derived from either embryos or from adult stem cells that have been reprogrammed (or "induced") to enter an embryonic stem cell-like state. The latter are called induced pluripotent stem cells.

Tissue-specific stem cells have been identified in many organs and tissues, including brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis. They are undifferentiated cells that are able to self renew and differentiate. Since their primary role in a living organism is to maintain and repair the tissue in which they are found, their capacity for differentiation is usually limited to cell types in the organ of origin.Footnote 1 So, for example, neural stem cells can become any type of cell in the brain or spinal cord but cannot differentiate into heart cells unless they have been reprogrammed into induced pluripotent stem cells.

Cancer stem cells (also known as tumor initiating cells) are a resilient subset of cells found in tumors with the capacity to self-renew and differentiate. They've been identified in many types of solid tumor cancers, including cancer of the breast, head and neck, lung, prostate, pancreas and glioblastoma. Cancer stem cells appear to be preferentially resistant to both standard chemotherapy and radiotherapy. Although cancer stem cells are not part of regenerative medicine (they regenerate cancer tissues thereby destroying normal tissues), they are an important aspect of stem cell research.

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