Carbon nanotubes induce mineralization of human cementoblasts

Abstract

IntroductionCarbon nanotubes (CNT) are one of the allotropes of carbon with unique properties. CNT shows good bone-tissue compatibility and has been reported to induce osteogenesis regarded as an ideal material in wide range of applications. However, the therapeutic effect of CNT-containing materials in the healing of apical periodontal tissue is unknown. The purpose of this study was to clarify the effect of CNT on proliferation and mineralization of the human cementoblast cell line (HCEM). MethodsProliferation of HCEM cells with CNT stimulation was assessed by MTS assay performed from 24-72 hours. Calcium deposition levels were evaluated by alizarin red S staining on day 7 and 10 and mineralization-related gene expression was examined by quantitative real-time PCR on day 3,7 and 10. Scanning electron microscopy was used to observe the culture with CNT on day 14. ResultsCNT showed no cytotoxicity to HCEM cell proliferation. Treatment with mineralization medium, CNT induced HCEM mineralization on day 7 and increased calcium deposition on day 7 and 14. mRNA expression of alkaline phosphatase was significantly increased throughout the experimental period and bone sialoprotein on day 3 by CNT. Whereas no effect was found on mRNA expression of type I collagen. CNT was observed in attachment to the cell surface on day 14. ConclusionsCNT promotes mineralization of HCEM cells indicating the potential as a new bioactive component for apical periodontal tissue regeneration materials through the regulation of cementoblast mineralization.