Modification of porous calcium phosphate surfaces with different geometries of bioactive glass nanoparticles

In this study, the effects of bioactive glass nanoparticles' (nBGs) size and shape incorporated into hydroxyapatite/beta-tricalcium phosphate (BCP) scaffolds were investigated. We prepared a highly porous (>85%) BCP scaffold and coated its surface with a nanocomposite layer consisted of polycaprolactone (PCL) and rod (similar to 153 nm in height and similar to 29 nm in width) or spherical (similar to 33 nm and 64 nm in diameter) nBGs. Osteogenic gene expression by primary human osteoblast-like cells (HOB) was investigated using quantitative real time polymerase chain reaction (q-RT-PCR). We demonstrated for the first time that in vitro osteogenesis is dramatically affected by the shape of the nBGs, whereby rod shaped nBGs showed the most significant osteogenic induction, compared to spherical particles (regardless of their size). Importantly, the good biological effect observed for the rod shaped nBGs was coupled by a marked increase in the modulus (similar to 48 MPa), compressive strength (similar to 1 MPa) and failure strain (similar to 6%), compared to those for the BCP scaffolds (similar to 4 MPa, similar to 1 MPa and similar to 1 respectively). The findings of this study demonstrated that the shape of the nBGs is of significant importance when considering bone regeneration. (c) 2012 Elsevier B.V. All rights reserved.