Topographical control and characterization of Al/Al2O3 nanowire coatings for improved osseointegration of implant materials

摘要

Medical implants are a clinical reality and thousands of patients have been treated increasing in this way his life quality. Although many native materials have been used for bone implants, future biomaterials will include specific topographies to obtain the desired function. In this thesis, Al/Al2O3 nanowires (NWs) are suggested as possible coatings for improved osseointegration. The coatings have been fabricated by chemical vapour deposition (CVD) of the molecular precursor [tBuOAlH2]2. Depending on the deposition time four different densely coated nanostructures have been obtained. A 3D-model has been reconstructed using the Focus Ion Beam/Scanning Electron Microscopy (FIB/SEM) technique and software reconstruction tools and the surface properties have been characterised using well known techniques. Finally, the prepared Al/Al2O3 NWs have been biologically tested. The Al/Al2O3 coatings are here studied as models for a better understanding of the topographic effect of the features on the cells independently from the chemical effect. Human osteoblast cells (HOB) and normal dermal human fibroblast cells (NHDF) were cultured separately on the deposited Al/Al2O3 NWs to investigate a possible selective cell adhesion. Additionally, gene experiments have been performed in order to understand the effect of the different topographies on the osteogenic gene expression. Lastly, the cell monolayer rheology (CMR) has been used to quantify the mechanical behaviour of the cells.