Tissue engineering is a field of many diverse research groups, each specializing in just a few types of tissue or organ structures. There is a great deal going on, and some of it is out of the public eye simply due to language barriers and the fact that more obscure or less important tissues are involved. It all still needs to be done, however: all of the body fails with age, and thus all tissues are a target for regenerative treatments. Take the work of this Japanese research group, for example:
Salivary gland hypofunction, or xerostomia (dry mouth syndrome), induces various clinical problems, such as dental decay, bacterial infection, and swallowing dysfunction. Xerostomia caused by autoimmune disease and aging affects an increasing number of patients. The development of novel functional treatments for xerostomia is needed, as currently available therapies are only palliative in nature. Tissue stem cell transplantation and gene therapy are currently being investigated as potential approaches to the restoration of salivary gland function. The final goal of regenerative therapy is fully functional regenerative organ replacement for dysfunctional organs.
Previously, we developed a technology to reconstitute the organ germ (Organ Germ Method) using epithelial and mesenchymal stem cells. We have recently reported the regeneration of fully functional organs, such as teeth, hair and lacrimal glands, can be achieved by the transplantation of bioengineered organ germs. In this review, we describe the regeneration of the salivary gland as part of a feasibility study of a next-generation regenerative therapy.