Gene expression profiling by DNA microarray and histomorphometric analyses of healing bone around nanotextured implants

INTRODUCTION The geometry and surface characteristics of an implant generate a biomechanical environment that can greatly influence its relationships with the tissues. Varying surface topography was identified as a key element to influence cell morphology and function. However, little is known on how these surface characteristics modulate the biological response and bone healing events at the implant interface. It is increasingly recognized that biological events such as cell/matrix/substrate interactions are controlled by nanoscale features but the exact molecular mechanisms implicated in the cell response remain unknown. Nanopatterned surfaces created using an oxidative solution consisting in a mixture of sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) have been demonstrated to significantly influence the very early stages of in vitro osteogenesis. Since successful osseointegration depends on cell fate decisions (i.e. osteogenic vs. fibroblastic pathway), understanding the biological cascade that normally occurs locally at the bone-implant interface at early stages is of paramount importance to optimize bone healing. Our objective was to examine the effect of implant surface nanotopography on bone healing using gene expression profiling by DNA microarray, histology and histomorphometric analyses.