Gallic acid–coated nanolayer on mineral trioxide aggregate for regulating the inflammatory and differentiation cellular response profile of human dental pulp stem cells

Mineral trioxide aggregate (MTA) is a biomaterial used in endodontics due to its high bioactivity, antibacterial behaviors, and good biocompatibility. However, it has several disadvantages related to certain physical properties, including a long setting time and poor mechanical properties. Therefore, we hypothesized that coating MTA with gallic acid (GA) would regulate physical properties and lead to enhanced adhesion, proliferation, and secretion of angiogenic- and odontogenic-related proteins. This study examined whether MTA can be modified with GA to form GAMTA cement and evaluated its physicochemical and biological behaviors and immune suppression, angiogenesis, and odontogenesis capabilities. We soaked MTA in Tris buffer containing different concentrations of GA to coat the MTA powders. X-ray diffraction (XRD) and diametral tensile strength analyses were conducted to assess the physical characteristics of GAMTA. Then, we immersed GAMTA cement in simulated body fluid to evaluate its hydroxyapatite precipitation capabilities and silicon ion release profile. We used human dental pulp stem cells to assess the cell responses and the immunosuppressive, angiogenic, and odontogenic capabilities of GAMTA. The XRD results showed that GA was successfully coated onto MTA without the disruption or loss of MTA’s advantageous original structural properties. GAMTA demonstrated excellent physicochemical and biological properties, improving hydroxyapatite formation and angiogenic, odontogenic, and anti-inflammatory properties compared with MTA alone. Our results indicate that the GAMTA cement is a useful dental material for future tissue engineering and clinical applications.