Potential induction of bone regeneration by nacre: An in vitro study

Abstract

PURPOSE: Because of limitations of autogenous grafts, alternative bone substitute material was investigated for its capacity in promoting bone formation. This study compared the osteogenic effects of nacre (mother of pearl) and beta-tricalcium phosphate (β-TCP). MATERIALS AND METHODS: Human bone cells (HBCs) were obtained from the culture of bone tissues after orthognathic surgery. The HBCs were cocultured with nacre chips of the giant oyster Pinctada maxima and with β-TCP particles for 1, 2, 3, and 4 weeks. Cells of each week specimens were used to study alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC) gene expression by noncompetitive reverse-transcriptase polymerase chain reaction and to study BSP synthesis by means of an immunocytochemical technique in conjunction with fluorescent microscopy. RESULTS: Reverse-transcriptase polymerase chain reaction demonstrated stronger expression levels of ALP mRNA in HBCs cocultured with the nacre chips than those with β-TCP at weeks 2 and 4. BSP gene expression levels in HBCs with nacre were more intense compared with β-TCP at weeks 3 and 4. Although the OC gene expression level in HBCs with β-TCP was higher than those with nacre at week 2, the expression was not different at weeks 3 to 4. Immunocytochemical study revealed that BSP synthesis were presented in the nacre and β-TCP from week 2 and decreased toward week 4. CONCLUSION: This study indicated that nacre promotes ALP, BSP, and OC gene expression. © 2011 Lippincott Williams & Wilkins, Inc.