Dr. Lopez is a researcher and has been granted select funding to explore the potential role of equine adult stem cells in bone injury repair.
Appreciation for the potential of stem cell therapies should be balanced with healthy doses of optimism and skepticism.
Stem cell therapy has captivated worldwide audiences. As with any new discovery, stem cells may seem foreign, but enduring interest has sustained scientific investigation and clinical use. Promising early results coupled with accessibility to electronic media have helped increase enthusiasm for stem cell therapies. Despite unanswered questions, the understanding of stem cells has grown exponentially, and expectations of novel therapies for seemingly untreatable conditions are high.
The perpetual search for a panacea should be balanced, however, with healthy skepticism and discerning assessments. Compared with other treatment modalities, stem cell therapies are in their infancy; however, stem cell treatments may someday be standard medical care alongside similar “medical miracles” (eg, antibiotic therapies, vaccinations, artificial joint replacement).
What Are Stem Cells? Stem cell is a relatively nonspecific term, often categorized into two broad sources:
- Embryonic stem cells (obtained from embryo)
- Adult stem cells (obtained from fully differentiated tissue or organs)
An additional distinction is the capacity of the cell to differentiate into other tissues:
- Totipotent cells (differentiate into all tissue types)
- Pluripotent cells (differentiate into most tissues from any of the 3 germ layers)
- Multipotent cells (differentiate into tissues from same germ layer)
- Unipotent cells (differentiate into 1 tissue type)
Additional terms that classify the relationship between donor and recipient include:
- Autologous cells (obtained from and instilled into same organism)
- Allogeneic cells (obtained from different donor of same species as recipient)
- Heterologous cells (instilled into recipient from different species than donor)
To categorize a stem cell on a genetic level:
- Allogeneic stem cells are obtained from and instilled into organisms of the same species but antigenically distinct.
- Syngeneic stem cells are obtained from and instilled into genetically similar organisms.
- Multipotent stromal cells are commonly available in the veterinary market.