Optimization of a biomimetic model for tooth regeneration

Our goal is to create biomimetic three-dimensional (3D) tooth constructs as novel regenerative tools and models for bioengineered replacement teeth in humans. We use natural tooth development as a template to guide our biomimetic design, aiming to overcome disadvantages of artificial dental implants. Our biomimetic 3D tooth models are designed to facilitate the reciprocal interactions between the dental epithelium (DE) and dental mesenchyme (DM) that are required for dental cell differentiation and mineralized tooth formation. In this study we utilized tunable Gelatin Methacrylate (GelMA) hydrogel as a scaffold material for dental cell encapsulation. We hypothesized that GelMA formulas could be optimized to closely resemble the physiological properties of the natural tooth bud environment, thus facilitating bioengineered tooth formation. To test this, atomic force microscopy (AFM) was used to measure the elasticity of dental cell seeded GelMA constructs of three hydrogel formulas in order to identify those most closely resembling natural tooth bud tissues. Analysis of in vitro cultured DE/DM encapsulated GelMA constructs using bright field microscopy, metabolic assays, histology and immunofluorescent histochemisty, revealed distinct DE and DM cell behaviors in each GelMA formula. Subcutaneous implantation of dental cell seeded bilayered GelMA constructs resulted in mineralized tissue formation. We conclude that GelMA hydrogel formulas support dental cell differentiation, validating GelMA as a suitable platform for further development of a biomimetic tooth model.