Characterization and induction of cementoblast cell proliferation by bioactive glass nanoparticles

Cementum is a mineralized tissue that lines the surface of the tooth root enabling attachment of the periodontal ligament to the root and surrounding alveolar bone. Studies examining the mechanisms involved in the formation of root cementum have been hindered by an inability to isolate and culture the cells required for cementum production (cementoblasts). This study isolated and characterized cementoblast cells derived from rat molar periodontal ligament. It was observed that the isolated cells expressed F-Spondin, a cementoblast marker, while F-Spondin expression was not observed in the cells of other tissues such as gingival fibroblasts and osteoblasts. As expected, the isolated cementoblast cells also expressed osteocalcin (OC), bone sialoprotein (BSP), alkaline phosphatase (ALP), and type I collagen, demonstrating the presence of mineralized tissues genes in cementoblast cells. These cells showed high ALP activity and calcified nodule formation in vitro. Since cementogenesis could be a critical event for regeneration of periodontal tissues, this study investigated whether bioactive glass particles could affect the proliferation of cementoblasts since they are known to enhance osteoblast proliferation. It was found that the ionic products from bioactive glass nanoparticles increased cementoblast viability, mitochondrial activity, and induced cell proliferation. Together, these results show the characterization of cementoblast cells from rat molar periodontal ligament. Additionally, it was shown that bioactive glass nanoparticles induced cementoblast to proliferate, indicating that they could be a potential material for use in cement regeneration through tissue engineering.