The in vitro osteoclastic degradation of nacre

Osteoclast activity was studied on nacre, the mother of pearl (MOP) in order to assess the plasticity of bone resorbing cells and their capacity to adapt to a biomineralizcd material with a different organic and mineral composition from that of its natural substrate, bone. Pure MOP, a natural bioinineralized CaCO3 material, was obtained from Pinctada oyster shell. When implanted in the living system, nacre has proven to be a sustainable bone grafting material although a limited surface degradation process. Osteciclast stern cells and mature osteoclasts were Cultured on MOP substi ate and osteoclast precursor cells were shown to differentiate into osteoclasts capable of resorbing nacre Substrate. However, analysis of the organization of the cytoskeleton showed that both a sealing zone and a podosome Structure were observed oil the nacre substrate. Moreover, MOP resorption efficiency was consistently found to be lower than that of bone and appeared to be a limited process. (c) 2007 Elsevier Ltd. All rights reserved.