Low molecular weight molecules of oyster nacre induce mineralization of the MC3T3‐E1 cells

Abstract

The nacre layer from the pearl oyster shell is considered as a promising osteoinductive biomaterial. Nacre contains one or more signal molecules capable of stimulating bone formation. The identity and the mode of action of these molecules on the osteoblast differentiation were analyzed. Water-soluble molecules from nacre were fractionated according to dialysis, solvent extraction, and reversed-phase HPLC. The activity of a fraction composed of low molecular weight molecules in the mineralization of the MC3T3-E1 extracellular matrix was investigated. Mineralization of the preosteoblast cells was monitored according to alizarin red staining, Raman spectroscopy, scanning electron microscopy, and quantitative RT-PCR. Molecules isolated from nacre, ranging from 50 to 235 Da, induced a red alizarin staining of the preosteoblasts extracellular matrix after 16 days of culture. Raman spectroscopy demonstrated the presence of hydroxyapatite (HA) in samples treated with these molecules. Scanning electron microscopy pictures showed at the surface of the treated cells the occurrence of clusters of spherical particles resembling to HA. The treatment of cells with nacre molecules accelerated expression of collagen I and increased the mRNA expression of Runx2 and osteopontin. This study indicated that the nacre molecules efficient in bone cell differentiation are certainly different from proteins, and could be useful for in vivo bone repair.

Nacre, a Natural Biomaterial

“…Molecules isolated from nacre induced mineralization of the preosteoblasts extracellular matrix after 16 days of culture that was analyzed as hydroxyapatite by Raman spectroscopy. This study indicated that the nacre molecules efficient in bone cell differentiation are certainly different from proteins, and probably more related to peptides (Rousseau et al, 2003(Rousseau et al, , 2007. Molecules isolated from nacre, ranging from 50 to 235 Da, in induced red alizarin staining of the preosteoblasts extracellular matrix after 16 days of culture.…”

“…However, the aggregative property of these molecules during chromatography precludes the obtaining of a more purified active fraction. The presence of BMP-like molecules in WSM was supposed but not demonstrated (Rousseau et al, 2007). Molecules isolated from nacre induced mineralization of the preosteoblasts extracellular matrix after 16 days of culture that was analyzed as hydroxyapatite by Raman spectroscopy.…”

Nacre Compared to Aragonite as a Bone Substitute: Evaluation of Bioactivity and Biocompatibility

“…In mollusc shells, the aragonite and the protein matrix form a composite material (mineral matrix + organic matrix) called nacre. Taking into account that the mechanisms behind the construction of the different biomineralized tissues occur in similar fashion, it seems coherent to seek out materials that can substitute or induce the regeneration of bone tissue in other biomineralizing organisms, and this explains the attention given to corals and molluscs with shells 5,6,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] . Thus, this work has sought, through the gathering and comparison of the characteristics of clinical interest, to find in the residues from malacoculture the potential for obtaining an industrial input of low ecological/economic impact.…”

“…Nacre and biogenic aragonite are two materials of 25 , without inflammation and/or fibrous formations. In vivo and in vitro studies indicate the nacre as a biocompatible, biodegradable and osteocondutive material, which may attract and activate bone marrow stem cells and osteoblasts; the same was observed in biogenic aragonite [22][23][24][25][26][27][28][29][30][31][32][33][34][35] . The mechanical and tribological properties -as tensile, compression and bending strength, besides resistance to abrasion -of the nacre, comparatively better than that of pure aragonite, are due to its hierarchical structure of micrometric hexagonal tablets with mineral bridges and interlocking surfaces 36,[38][39][40][41][42] and cemented in organic matrix.…”

“…The mechanical and tribological properties -as tensile, compression and bending strength, besides resistance to abrasion -of the nacre, comparatively better than that of pure aragonite, are due to its hierarchical structure of micrometric hexagonal tablets with mineral bridges and interlocking surfaces 36,[38][39][40][41][42] and cemented in organic matrix. Considering that to this matrix are also attributed mineralizing and osteogenic properties 22,[30][31][32][33][34] , the hypothesis raised initially was that the nacre would present more pronounced osteogenic properties than the aragonite, disregarding this study any differences in the mechanical properties.…”