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How can I be assured that my patient’s stem cells will be available to them in the future? |
Our laboratory facilities are one of the largest full-service cryogenic labs in the world serving both domestic and international clients since 1982. Staffed with highly trained professionals, our FDA certified lab maintains the highest scientific standards in state-of-the-art facilities. In addition to the cryopreservation and banking of dental pulp, our facilities also bank unfertilized eggs, sperm, cord blood, and other human biological materials. Individuals and families have trusted and depended on our laboratory’s facilities and services for their very personal family and health
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What are stem cells? |
Stem cells are unique cells that have the ability to replicate and differentiate into other cell types and tissues. Adult stem cells are also known as progenitor cells. Stem cells have been isolated from a variety of body tissues, including embryonic tissue, postnatal (adult) tissues, bone marrow and dental pulp. Stem Cells are usually difficult to identify from the cells surrounding them. They are often buried deep within tissues and organs and spread diffusely throughout. Embryonic stem cells are pluripotential cells that divide and grow rapidly and differentiate into the 220 specific tissue types that make up the human body, these include muscle, nerve, and the components of the blood.
When a stem cell divides, one daughter cell remains a stem cell while the other daughter cell or progenitor cell differentiates into a particular cell type. Keeping one daughter cell as a stem cell is a characteristic trait of stem cells known as self-renewal. Fetal stem cells are said to be pluripotent, meaning that they are capable to giving rise to all cells and tissues. Stem cells are also described as multipotent, meaning that they have the ability to differentiate into multiple cell types. Studies have shown that stem cells are able to divide both in vivo and in vitro.
Embryonic stem cells differentiate into the three embryonic germ layers: ectoderm, endoderm and mesoderm. Stem cells from these germ layers later generate particular cell types as organs and tissues are formed.
Ectoderm gives rise to the epidermis (skin), nails, hair, glands of the skin, the nervous system, the ears, the eyes (including the retina and lens), mammary glands, and the mucous membranes of the mouth and anus. The embryologic neural crest is also derived from ectoderm, which later gives rise to the cranial and spinal ganglia in the central nervous system.
Mesoderm gives rise to connective tissue, skeleton, bone, cartilage, skeletal muscles, blood and blood vessels, the lymphatic system, the linings of the major cavities of the body (pleura, pericardium, peritoneum), heart, spleen, kidneys and the sex organs.
Endoderm gives rise to the respiratory tract (trachea, lungs, pharynx), thyroid and parathyroid glands, digestive tract (stomach, liver, pancreas, colon), the lining of the bladder, and the urethra.
Stem cells from the embryonic germ layers give rise to the structures of the head and neck. For example, ameloblasts are derived from ectoderm, and form enamel. Fibroblasts are derived from mesoderm, which generate connective tissue, dermis, muscle, bone and cartilage. In fact, all tooth structures, with the exception of enamel, are derived from mesoderm. Endoderm later gives rise to the formation of blood vessels.
Fetal or embryonic stem cells exist during embryonic development, and are able to differentiate in virtually any cell type, and can self-replicate for numerous generations. Multipotent adult stem cells are more tissue-specific, and often give rise to just one cell type. Adult stem cells are also known as post-natal cells, and reside in many body tissues following birth, including bone marrow, skin, neural tissues, hair follicles, dental pulp, skeletal muscle and brain. Adult stem cells are responsible for the repair of diseased and injured tissues and organs.
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How have stem cells been used in medical research? |
Skeletal stem cells isolated from bone marrow stromal cells (non-blood forming cells in bone marrow) are able to regenerate all types of skeletal tissues, including cartilage, bone, as well as blood-supportive stromal cells and fat cells in the marrow. In cardiology, bone marrow-derived mesenchymal stem cells differentiate into cardiomyocytes and vascular endothelial cells, and secrete paracrine factors that are both cytoprotective and angiogenic. The ability of these cells to differentiate into specific cell types, as well as their ability to secrete essential substances for cellular growth, function and survival suggests that these cells play an important role in the repair of cardiac disease. Stem cells from the blood have been used extensively in hematology for the treatment of blood dyscrasias and cancers via bone marrow transplantation. Research suggests that stem cell transplantation directly into the basal ganglia of the brain may be able to replace nerve cells destroyed by Parkinson’s disease and other neurodegenerative illnesses
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Where are stem cells located? |
Mesenchymal stem cells are found in bone marrow, adipose tissue, blood vessel walls, synovium, muscle, placenta and umbilical cord blood. Recently, it has been discovered that these cells are also found in dental pulp, periodontal ligament and the periosteum.
Dental pulp contains a variety of cell types, including fibroblasts, odontoblasts, lymphocytes, histiocytes, erythrocytes, neurons, and undifferentiated mesenchymal cells. An abundant source of these undifferentiated mesenchymal cells in permanent teeth is in the dental pulp of immature, impacted third molars.
Recently, investigators have discovered a unique type of mesenchymal stem cell in the dental pulp of deciduous teeth. Stem cells from deciduous teeth, begin at the 6th week during the embryonic stage of human development.. Nicknamed ‘SHED” (Stem Cells from Human Exfoliated Deciduous teeth), scientists believe that these stem cells behave differently than post-natal (adult) stem cells. SHED cells multiply rapidly and grow much faster than adult stem cells, suggesting that they are less mature, so they have the potential to develop into a wider variety of tissue types. Further, SHED cells are able to express proteins on their cell surfaces that allows them to not only differentiate into dental pulp, bone and dentin, but also into neural and fat cells (adipocytes). In fact, SHED cells differentiate into nerve cells more readily than adult stem cells isolated from permanent teeth. SHED cells express a variety of neuronal and glial cell markers which directly reflects the embryonic neural crest origin of dental pulp. SHED cells have been shown to express factors that induce bone formation and assist with the guidance of the eruption of the permanent teeth.
The periodontal ligament serves as a reservoir for many cell types, including fibroblasts, osteoblasts/clasts, cementoblasts/clasts, and odontoclasts. The remarkable characteristic of the periodontal ligament is its ability to regenerate and repair virtually every other tissue type that comprises the periodontium. Undifferentiated mesenchymal cells of the periodontal ligament can differentiate into osteoblasts, chondrocytes and adipocytes.
New research has shown that postnatal stem cells are also found in the periodontal ligament. Ligament removed from extracted third molars transplanted into culture yielded multiple rapidly dividing colonies of stem cells that expressed specific proteins characteristic of postnatal stem cells. The replication rate of these stem cells was similar to that of dental pulp stem cells. Following transplantation into mice, these stem cells produced cementum, periodontal ligament and fibrous structures similar to Sharpey’s fibers, which anchor cementum to bone.
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How can dental stem cells be used in dental and craniofacial tissue engineering? |
Adult stem cells may be used to regenerate bone and correct craniofacial defects. Both in vitro studies and in vivo research in animal models has shown that tooth-derived adult stem cells can be used to regrow tooth roots in the presence of proper growth factors and a biologically compatible “scaffold.” Regenerative therapy is less invasive than surgical implantation, and early animal studies suggest comparable results in strength and function of the biological implant as compared to a traditional dental implant.
Dental stem cells are capable of extensive proliferation and multipotent differentiation, which makes them an important resource of stem cells for the regeneration and repair of craniofacial defects, tooth loss and bone regeneration. Given their ability to produce and secrete neurotrophic factors, SHED cells may also be beneficial for the treatment of neurodegenerative diseases and the repair of motoneurons following stroke or injury. Stem cells from third molars release chemicals that may allow the remaining nerves to survive the injury. Future research will investigate if using tooth-derived stem cells can be used to regenerate neurons following spinal cord injury.
Stem cells extracted from the dental pulp of a third molar could be harvested, then directly implanted into the pulp chamber of a severely injured tooth. The goal is to regenerate the pulp inside the damaged tooth, preventing the need for endodontic treatment.
Stem cells derived from the periodontal ligament may offer promise for regenerating the periodontal ligament and other supporting structures of the periodontium that have been destroyed by gingival disease, with an alternative approach to traditional clinical therapies.
Tissue-engineered bone grafts will be useful for practitioners in all of the dental specialties. Future tissues may also include engineered joints and cranial sutures, which would be especially helpful to craniofacial and oral maxillofacial surgeons.
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How are stem cells harvested from teeth and dental tissues? |
Adult stem cells can be harvested from the pulp of primary and permanent teeth, by removing the periodontal ligament from extracted teeth, saving bone fragments during placement of dental implants, and by collecting bone marrow after tooth extraction. Mucosa, muscle and periosteum – non-pathologic tissues removed from the oral cavity that otherwise would be discarded – can contain stem cells that are able to be cryopreserved. Dental stem cells can be recovered immediately following exfoliation of a deciduous tooth, but are best recovered after the extraction of deciduous teeth as the teeth become mobile, but still maintain their circumferential gingival attachment.
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How will I know whether or not the stem cells in the pulp of the tooth are viable? |
The blood supply to the pulpal tissues enters through the apical area of the tooth. Therefore, when a tooth is extracted, the pulp should appear red in color, indicating that the pulp received blood flow up until the time of removal, which is indicative of cell viability. When a tooth is extracted, if the pulp is gray in color, it is likely that blood flow to the pulp has been compromised, and thus, the stem cells are likely necrotic and are no longer viable for recovery. Teeth that become very loose, either through trauma or disease (e.g. Class III or IV mobility), often have a severed blood supply, and are not candidates for stem cell recovery. This is why recovery of stem cells from deciduous teeth is preferred after an extraction versus the tooth that is “hanging on by a thread” with mobility. Pulpal stem cells should not be harvested from teeth with apical abscesses, tumors or cysts.
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What is sustentation? |
Following an extraction of either a deciduous or permanent tooth or another appropriate surgical procedure, the dentist places the tooth/tissue sample in a screw-top vial containing a hypotonic phosphate buffered saline solution, which provides nutrients and helps to prevent the tissue from drying out during transport. Placing a tooth into this vial at room temperature induces hypothermia. The vial is then carefully sealed and placed into the thermette, a temperature phase change carrier, after which the carrier is then placed into an insulated metal transport vessel. The thermette along with the insulated transport vessel maintains the sample in a hypothermic state during transportation. The viability of the stem cells is both time and temperature sensitive, and careful attention is required to ensure that the sample will remain viable.Time from harvesting to arrival at the processing storage facility should not exceed 40 hours.
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Can I place more than one tissue sample/tooth in the same vial? |
Up to four teeth or tissue samples can be placed in the same vial. Our staff at the processing and storage facility will assess for cell viability in all of the teeth that have been sent. When multiple extractions are planned we encourage recovering up to four teeth with healthy pulp.
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Which deciduous teeth can be sent? |
Vital anterior deciduous teeth from either the mandible or maxilla can be sent. Deciduous teeth distal to the canine are not recommended for sampling, because of anatomical considerations. For example, deciduous molars have a broader root base, and therefore, are retained in the mouth for a longer period of time than anterior teeth. Eruption of the posterior permanent teeth generally takes a longer amount of time to resorb the deciduous molar roots, which may result in an obliterated pulp chamber that contains no pulp, and thus, no stem cells. In some instances, early removal of deciduous molars for orthodontic considerations (e.g. early intervention for space maintenance) will present an opportunity to recover these teeth for stem cell banking.
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How are dental stem cells transported for storage? |
The dentist places the sealed insulated metal shipping vessel into a Styrofoam holder within a rigid cardboard box provided by StemSave. The package is then transported via UPS next day air saver to the storage facility. Upon arrival at the storage facility, the labeling of the sample and the shipping container is verified to ensure that the tissue sample matches the correct donor. The sample is then assessed for cell viability. If the cells are viable, the tissue will be further processed and prepared for freezing.
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What if the cells in the sample are not viable for use? |
All tissue samples submitted to StemSave are assessed for cell viability. If, after testing, it is determined that the cells are not viable, both the account holder and the dentist will be notified that the sample was received and that there were no viable stem cells. Because there were no viable cells to preserve, StemSave will credit the account holder their full payment and will be provided with a list of possible reasons for the lack of viability. Both the StemSave member and the dentist will be encouraged to submit a second sample, when possible, following enclosed guidelines to ensure that a proper tissue sample is recovered. Samples that are not deemed viable will not be stored.
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How are stem cells stored? |
Stem cell samples are cryogenically preserved and stored indefinitely at our FDA registered storage facility. This certified facility specializes in the cryopreservation of many tissue types, and has a continuous 25 year history of successful medical tissue banking. The state of the art cryopreservation methods used are standard to the medical industry.
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What is cryopreservation? |
Cryopreservation is the process of preserving cells or whole tissues by cooling them to sub-zero temperatures. At these freezing temperatures, biological activity is stopped, as are any cellular processes that lead to cell death. Dental stem cells can be successfully stored long-term with cryopreservation and still remain viable for use. These cells can be cryopreserved for an extended period of time, and when needed, carefully thawed to maintain their viability.
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Why should individuals “bank” their own stem cells? |
If needed, using your own stem cells (autologous donation) poses fewer risks for developing an immune reaction, “graft rejection,” following transplantation than using donated tissues. Autologous donation also avoids the risk of contracting pathogens from the transplanted tissue that may induce disease in the new host.
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Can my patients use their “banked” dental stem cells now? |
At the present time, stem cells are being used in many life-saving therapies and clinical trials. The ability for your patients to use their banked stem cells immediately will be dependent upon what their needs are and whether there are any medical therapies for their utilization available now.
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Can someone donate dental stem cells for research purposes? |
StemSave is currently for autologous “self” stem cell storage only. StemSave in the future will participate in a special initiative as a partner with multiple federally regulated government agencies to create an extensive public bio-repository of stem cells for research and clinical testing for the development of medical therapies.
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A parent may ask: why should I have my children’s dental stem cells banked if we already had their umbilical cord stem cells banked? |
The most immediate answer to this question is that dental stem cells are banked at the time children are 6-7 years of age, up to adults.Parents who chose to save their children’s cord blood already understand the value of banking stem cells. Banking stem cells from teeth still makes sense for those that have stored their umbilical cord blood. Cord blood stem cells are hematopoietic [blood related] stem cells while stem cells from teeth are mesenchymal [tissue related] stem cells. They possess different properties and characteristics and are used for different treatments – with cord blood primarily used to treat blood disorders and cancers and mesenchymal stem cells [the kind of stem cells recovered from teeth] utilized for tissue damage as well as a treatment for a variety of cancers, neurological, autoimmune, and metabolic disorders. Hence, it makes sense to bank both types of stem cells. In a demonstration of the value of both types of stem cells, cord blood banking services now offer families the opportunity to bank both their cord blood and the cord – which is rich in mesenchymal stem cells.
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