27 May 2010

Teeth from stem cells in a different manner

Currently, the problem of restoring lost teeth is solved with the help of traditional dentures or intra-maxillary dental implants. Implants are superior to prostheses in a number of parameters, but the procedure for their installation is very painful, lengthy, requires multiple visits to various specialists and may end in failure. Moreover, implants are not able to change their shape following the inevitable age-related changes in the shape of the jaw bones and adjacent teeth. Methods of growing new teeth from stem cells developed in recent years (see, for example, the article Etsuko Ikeda et al. Fully functional bioengineered tooth replacement as an organ replacement therapy) are based on the use of embryonic dental rudiments, so their introduction into the clinic will certainly cause protests from the guardians of morality.

Researchers at Columbia University Medical Center, working under the guidance of Professor Jeremy Mao, offer a fundamentally new method of restoring lost teeth, which in the future will allow in a fairly short time to grow new anatomically correct teeth directly in the patient's mouth. The results of their work are published in the Journal of Dental Research in the article "Anatomically Shaped Tooth and Periodontal Regeneration by Cell Homing"

According to the technology proposed by Mao and colleagues, a skeleton obtained by three-dimensional printing from a hybrid of biocompatible polymers: caprolactone and hydroxyapatite is implanted into the jaw bone. The framework is permeated with tubules with a diameter of 200 micrometers, which are pre-filled with specific cell growth factors: stromal factor-1 (stromal-derived factor-1, SDF1) and bone morphogenic protein-7 (bone morphogenetic protein-7, BMP7). These factors attract the body's own stem cells into the framework and direct their differentiation in the right direction, eliminating the need to isolate stem cells and cultivate them in the laboratory. The resulting structure, which has the anatomical shape of a tooth, is integrated into the surrounding tissues, which is absolutely impossible to achieve when using metal or other materials.

The developers tested the described method on 22 rats implanted with skeletons shaped like human molars and rat incisors. At the same time, the incisor skeletons were implanted in place of previously removed own teeth, and the molar skeletons were implanted on the back surface of the jaw. Nine weeks after implantation, new bone tissue and a periodontal ligament were formed at the point of contact between the skeleton and the alveolar bone. A comparison of the results obtained during implantation of empty skeletons and skeletons filled with growth factors showed that the latter not only attracted a significantly larger number of endogenous stem cells, but also provided more pronounced angiogenesis (formation of new blood vessels) in the implantation zone.

Experts believe that the technique developed by the authors has a huge potential and in the future will allow growing practically "new" teeth in place of lost teeth, not only looking good and performing their functions, but also, possibly, not wearing out throughout a person's life.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru Based on the materials of Columbia University College of Dental Medicine: Body's Own Stem Cells Can Lead to Tooth Regeneration.


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