Stem cells for the restoration of dental pulp
If the tooth is severely damaged as a result of deep caries or trauma, the living tissues forming the sensitive dental pulp are exposed and exposed to pathogenic bacteria. When the dental pulp is infected, it is possible to get rid of painful symptoms only by cleaning and filling the dental canals or removing the tooth.
An X-ray image of a tooth with a deep carious cavity (green arrow) and an infection attached (blue arrows).
Researchers at Tufts University, working under the guidance of Professor Pamela Yelick, have proposed an alternative way to get rid of the problem, which consists in introducing stem cells into damaged teeth using a biological material based on collagen.
According to the authors, endodontic treatment, such as depulpation of dental canals, actually kills a living tooth. Such depulpated teeth eventually become brittle and often require prosthetics. This can be avoided with the help of an approach developed by researchers that allows to restore a damaged tooth while preserving its functions.
This approach consists in encapsulating a mixture of dental pulp stem cells isolated from removed "wisdom teeth" and endothelial cells of the human umbilical vein, providing the formation of new blood vessels, in a hydrogel made of methacrylate gelatin (GelMA). This cheap material, obtained from collagen, acts as a framework that ensures the growth of new dental pulp.
As part of the experiment, a hydrogel containing a mixture of cells was injected into the channels of damaged human teeth, which were previously removed during independent clinical treatment of patients and completely cleaned of living tissue. After that, the roots were implanted in immunodeficient rats and their condition was monitored for 8 weeks.
Two weeks after implantation, pulp-like tissue was detected in the cavities of the dental canals, and four weeks later, the researchers registered increased cell growth and the formation of blood vessels. After eight weeks, the pulp-like tissue completely filled the dental canals, while it had a highly organized vascular network filled with blood. In addition, the researchers found formed protrusions of cells firmly adhered to dentin – the hard bone tissue that forms the body of the tooth. At the same time, implantation did not cause inflammation of the surrounding tissues, and no inflammatory cells were detected inside the implanted dental canals, which confirmed the biocompatibility of GelMA.
During control experiments involving implantation of empty dental canals and dental canals filled only with GelMA in animals, the formation of an insignificant number of disorganized blood vessels, as well as complete or almost complete absence of adhesion to dentin, was recorded.
The results obtained by the authors indicate that implantation of dental stem cells and umbilical vein endothelial cells encapsulated in GelMA is a promising strategy for restoring the functions of damaged teeth. However, the researchers note that the work carried out did not evaluate the formation of new nerve fibers in the dental pulp tissue. They also emphasize the need for additional safety and efficacy studies in larger animal models before clinical trials can be planned.
Article by Khayat et al. GelMA Encapsulated hDPSCs and HUVECs for Dental Pulp Regeneration is published in the Journal of Dental Research.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Tufts University: New stem cell delivery approach regenerates dental pulp-like tissue in a rodent model.
22.12.2016