Surface topography and chemistry have significant influences on the biological performance of biomedical implants [1,2].Chemically,the surface of implant can be modified by incorporating biocompatible trace elements which are essential for normal bone metabolism [3].Physically,the surface topography at both micro-and nano-scales plays a major role in modulating the interactions of implants and cells/tissues,thus influencing the osseointegration of the implants [4,5].Our aim is to produce an implant surface with favourable biological properties by dual modification of surface chemistry and topography in simple processes.Results demonstrated that introduction of Nb2O5 resulted in the formation of Ti0.95Nb0.95O4 solid solution and led to the generation of nanoplate network structures on the TiO2 coating surface.By contrast,the addition of SiO2 resulted in a hairy nanostructure and co-existence of rutile and quartz phases in the coating.The introduction of Nb2O5 enhanced the corrosion resistance of TiO2 coating.Nb2Os/TiO2 coating could enhance osteoblast adhesion and promoted cell proliferation,while TiO2coatings with SiO2 were inferior in their bioactivity.Further experiments were conducted to investigate the microstructures and cytocompatibility of SiO2/TiO2 coatings etched by hydrogen fluoride solution in hydrothermal conditions.Results indicated that nanoporous topographies were formed on the surface of the SiO2/TiO2 coatings and the hydrothermal parameters had important influences on the size and shape of the pores.The interconnected network pores on the coating surface could only produce at the appropriate hydrothermal conditions.Nanoporous SiO2/TiO2 coatings could enhance osteoblast adhesion and promote cell proliferation.Our results suggest that the Nb2O5/TiO2 coatings with nanoplate structures and SiO2/TiO2 coatings with nanoporous structures can enhance the biological performance of TiO2 coatings,suggesting its potential use in modification of biomedical TiO2 coatings in orthopaedic applications.