What are placental stem cells and what are placental stem cells used for? As placental stem cells get explored for a variety of therapeutic applications, these questions become increasingly important. The opportunity to collect placental stem cells is also a once in a lifetime opportunity.
In this article:
- What is the Placenta?
- What are Placental Stem Cells?
- Placental Stem Cell Banking
- Clinical Applications of Placental Stem Cells
- Placental Stem Cell Injection
- Are Placental Stem Cells Pluripotent?
What is the Placenta?
The placenta is an organ that connects the developing fetus to the uterine wall, allowing a flow of nutrients, gases, and hormones between the mother and the fetus during pregnancy. The placenta is a maternal-fetal organ that joins the mother and fetus during pregnancy. Although it serves many functions, its primary role is to transport oxygen (O2) and nutrients from the mother and facilitate the release of carbon dioxide (CO2) and waste from the developing baby.
Because of its role in blood and oxygen transportation, the placenta is rich in blood vessels. During the birthing process, the placenta and the fetal membranes are expelled from the mother.
After childbirth, blood remains in the placenta, which can be collected and stored for a fee for future therapeutic use.
What are Placental Stem Cells?
Placental stem cells are a type of stem cell that is derived from a newborn’s placental blood or tissue.
Perinatal is a term that defines the short period right before to right after birth. When the baby is born, blood remains in the placenta. Both the placental blood and tissue are rich sources of perinatal stem cells.
Placenta stem cells include a variety of perinatal cell types, including:
- The maternal part of the placenta, called the decidua
- The amniotic and chorionic membranes
- The chorionic villi
Other afterbirth components include the umbilical cord blood and the umbilical cord tissue. These tissues are rich in hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs), respectively.
Placental Stem Cell Banking
Because the placental is a valuable source of stem cells, companies such as LifebankUSA offer private storage services for placental blood and tissue. In July 2017, LifebankUSA released its 50th cord blood unit for transplant. Ten of its 50 transplants (20%) have involved placenta blood stem cells, making it the market leader in this area. No other stem cell bank worldwide has yet to release a placenta stem cell unit for use in transplant.
Based in New Jersey, Celularity is a biotechnology company that specializes in leveraging biologically active cell populations within the postpartum human placenta. Founded on the pioneering work of Robert Hariri, MD, PhD, in human placenta-derived cellular therapeutics and biomaterials, Celularity is leveraging the biocreative event on earth: human birth.
Americord Registry is another company that offers placental blood collection and storage within the U.S. In July 2019, Americord launched its Placental Tissue 2.0TM service, allowing families to store two types of stem cells from placental tissue, including MSCs and amniotic epithelial cells (or AECs). In other parts of the world, a growing number of companies are also now offering placental blood and tissue storage services.
Within India, one example of such company is ReeLabs, a private cord blood bank that offers storage services for more than 10 different types of tissues.
Clinical Applications of Placental Stem Cells
As mentioned, Celularity is exploring a variety of potential applications for placental stem cells, including longevity and augmented immunity applications. As stated by Celularity’s Founder and CEO, Dr. Robert Hariri, “When I realized the placenta is perhaps the most valuable, never before considered biological resource, I committed that I would find a way to collect and process it into products.”
Another company that is exploring clinical applications of placental stem cells is Pluristem Therapeutics. Based in Israel, Pluristem Therapeutics (PSTI) is a clinical-stage cell therapy company that is a world leader in cell therapy manufacturing and placental-derived products.
Pluristem has developed PLX cells, which are adherent stromal cells or mesenchymal-like cells collected from post-partum human placentas. It collects the placentas from consented donors, after which it extracts and collections a target cell population. Next, it expand the cells using proprietary bioreactors to produce a large number of doses, approximately 20,000 doses (20,000 treatments) from a single placenta.
Pluristem has treated hundreds of patients across the globe for different indications within its clinical trial programs.
Placental Stem Cell Injections
There are a variety of perinatal stem cell types that are used within stem cell injections and treatments. For example, umbilical cord blood stem cells are used within hematopoietic stem cell cell transplantation (HSCT) and mesenchymal stem cells present in umbilical cord tissue are being explored in clinical trials worldwide.
However, placental stem cell injections are uncommon. This is because placental stem cell therapies require formal clinical trials under the oversight of national regulatory bodies. This is why Pluristem Therapeutics has multiple clinical trials underway to explore the therapeutic potential of its placental-derived PLX cells.
Whether or not a stem cell requires a clinical trial to be utilized by medical professionals depends on several factors. These factors are described within specific sections of the FDA code. In the U.S., cellular therapies are regulated by the FDA’s Office of Cellular, Tissue, and Gene Therapies (OCTGT) within the FDA Center for Biologics Evaluation and Research (CBER).
Placental stem cells are cells sourced from the placenta, which is collected after delivery of full-term healthy babies. The cells are completely non-controversial. If a family does not elect to store its placenta, then it gets discarded as medical waste. With approximately 4 million births per year in the U.S., only a small fraction of placental blood and tissue is preserved (a fraction of 1%).
In contrast, embryonic stem cells (ESC) are cells derived from embryos at fertility clinics with informed donor consent. They are harvested shortly after fertilization, within 4-5 days. Embryonic stem cells are the only controversial stem cell type. They are derived from blastocysts, a stage in the developing embryo and can become any cell type within the human body.
Are Placental Stem Cells Pluripotent?
To understand whether placental stem cells are pluripotent, you need to understand the following definitions:
- Totipotent stem cells – Cells that have the capacity to form an entire organism
- Pluripotent stem cells – Cells that can give rise to most, but not all, tissues within an organism
- Multipotent stem cells – Undifferentiated cells that are limited to giving rise to specific populations of cells
Placental stem cells are not totipotent, because only two types of stem cells have this capacity: embryonic stem cells, and a reprogrammed type of stem cell, known as an induced pluripotent stem cell (iPS cell).
Although it generally believed that pluripotent stem cells do not exist beyond the first few weeks of fetal development, the placenta does contain a variety of stem and progenitor cell types that reflect its embryonic origin. Placental stem cells are most likely multipotent. Meaning, they are destined to become specific populations of cells.
Would you preserve your newborn’s placental stem cells? Share why or why not in comments below.