Synergic deposition route for the functionalisation of biomedical devices

Titanium has been widely used for dental implants due to its biocompatibility, corrosion resistance, and mechanical properties. In order to improve osseointegration, the Ti surface is generally functionalized. A typical methodology for surface modification is the coating of Ti substrates with bioactive layers of calcium phosphate ceramics (CPCs) [1]. However, CPC coatings on metal implants usually suffer from poor adhesion. With the aim of improving the adhesion strength, the insertion of dense and compact ceramic interlayers is reported to be useful[1]. Among various ceramics, crystalline TiO2 has been extensively used thanks to its well-known biocompatibility and bioactivity [2]. In this work, a multi-step solvent free process is proposed, with the aim of obtaining a final composite material made up of a dense, compact and crystalline titania inter-layer (obtained via Metal Organic Chemical Vapour Deposition technique) and of a homogeneously spread discontinuous CPC toplayer, with particular chemical composition, crystallinity and morphology (obtained by means of water-based spray pyrolysis technique). Finally, a thermal treatment is carried out. These synthesis approaches are relatively simple and economic, eco-compatible and consequently suitable for an easy industrial scale-up of the process. The morphology, crystalline structures and wettability of the coated surfaces is here presented. Moreover, ions release and in vitro acellular bioactivity have also been evaluated.