Abstract
In this study, we aimed to construct an injectable hydrogel composed of gelatin methacryloyl/hyaluronic acid (GelMA-HA) and combine it with lyophilized concentrated growth factors (CGF) and dental pulp stem cells (DPSC) to promote the process of periodontal regeneration. We confirmed that bioactive lyophilized CGF can be anchored to hydrogels by Schiff base imine bonding, thereby achieving effective sustained release of various growth factors in the inflammatory microenvironment of periodontal bone destruction. Meanwhile, this hydrogel can provide a 3D cell growth microenvironment to improve the survival rate of dental pulp stem cells. GelMA-HA-CGF-DPSCs exhibit remarkable ability to promote cell proliferation and differentiation as well as excellent biocompatibility. In vitro experiments demonstrated that this system can increase alkaline phosphatase activity, enhance osteogenic mineralization capacity, and significantly upregulate the expression of osteogenesis-related genes and proteins. In the rat alveolar bone defect model, the experimental group significantly facilitated regeneration of periodontal bone. These findings suggest that this injectable composite material has the potential to overcome the limitations of CGF applications and stem cell injections. Specifically, through the chemotactic effects of growth factors and intercellular interactions, endogenous stem cells can also attract endogenous stem cells. Serving as a scaffold structure, it creates an osteogenic microenvironment and provides a space for bone regeneration. Moreover, its injectability and fluidity can achieve minimally invasive periodontal treatment in a noninvasive manner. The findings of this study are expected to provide valuable insights and references for the clinical translational repair treatment of periodontal bone defects caused by periodontitis.