Tissues typically discarded at birth (e.g. placenta, umbilical cord) is another rich source of stem cells that boast some unique properties that set them apart from adult stem cells. While adult stem cells need to be a match (much like blood transfusions) to avoid rejection by the recipient’s immune system, stem cells of umbilical cord and placental origin do not need to be matched. This is because the young cells present in birth tissues have not fully developed the surface proteins (“HLA markers”) found on the outer membranes of adult cells, and thus are able to “fly under the radar” of the recipient’s immune system. This immune-privileged status makes the transplant an easier task: instead of harvesting the cells from the patient that carries surgical risks, the doctor can now open the stem cell “medicine cabinet” to administer precise doses.
Stem cells of birth tissue origin have another unique advantage: These cells are young and have been shown to be therapeutically more active. While we do not yet know all of the mechanisms by which stem cells promote healing, we do know that these cells produce cytokines and growth factors, and recruit local cells to perform work of repair and regeneration. When birth tissue stem cells are compared to adult stem cells, they demonstrate higher level of secretion of cytokines and growth factors, higher speed of differentiation, slower cellular aging, stronger anti-inflammatory effects, and higher number of future cell divisions before eventual cell death. Also, studies have shown that umbilical cord stem cells have greater neuroprotective and neurorestorative properties compared to adult bone marrow stem cells.
Yet, it may not simply be the cells that are exerting therapeutic benefits. Recent study out of Stanford University showed that umbilical cord blood contains an abundant supply of a valuable protein called TIMP-2, which has shown to improve memory and learning, through improving hippocampal function.
1. Amniotic Membrane
Amniotic membrane products have been rapidly advancing in quality and popularity in the last few years. They show greater long-term efficacy over PRP (platelet rich plasma) or cortisol injections. Using these products does not require matching, because while the chorionic (maternally facing) membrane presents HLA markers, the fetal-facing membrane (amnion) is immune-privileged and can be used in allogeneic applications (transplantation into a different individual).
Umbilical cord tissue is a dense source of MSC’s, mainly from a gelatinous material surrounding the blood vessels of the cord, called Wharton’s jelly (WJ). MSC’s (mesenchymal stem cells) were shown to have the capacity to differentiate into bone, cartilage, fat, skeletal muscle, cardiac muscle, and even neurons, or cells of the kidney, liver and pancreas. MSC’s from umbilical cords are more primitive than MSC’s derived from more mature tissue sources, and have intermediate properties between embryonic and adult stem cells. They have anti-inflammatory, immune-modulating, antimicrobial and anti-tumorigenic properties, are able to home in to sites of injury, and send out signals to recruit local cells to participate in rescue and repair. MSC’s from WJ may also be particularly helpful in the treatment of neurodegenerative conditions.
Umbilical cord blood contains hematopoietic CD34+ stem cells, which for decades have been used to treat the same panel of conditions for which bone marrow transplants were used for. Hematopoietic stem cells also help with angiogenesis (generating blood vessels) thus help ensure blood supply to the repaired tissue. There is also evidence, that a more naïve progenitor cell is present exclusively in cord blood. Recently, a valuable protein TIMP-2 was found to be abundant in the umbilical cord blood, and TIMP-2 was shown ng and hippocampal health.
*All donated cords are the by-products of normal, healthy births. At our lab, each cord is carefully screened for sterility and infectious diseases under American Association of Blood Bank standards.