Micropattern of nano-hydroxyapatite/silk fibroin composite onto Ti alloy surface via template-assisted electrostatic spray deposition

The surface topography plays an important role in bone formation, which may present specific physical cues to cells and tissues and further improve the bioactivity or osteoconduction of the implants. In this report, nano-hydroxyapatite/silk fibroin (n-HA/SF) composite were prepared via a simplified coprecipitation method. Then these nanocrystals were deposited onto Ti alloy substrates via a template-assisted electrostatic spraying deposition (ESD) technique. The output voltage and flow rate were investigated to produce a cone-jet spraying of n-HA/SF suspensions. By using different types of precisely-designed templates (stripe, grid, and ring), the Ti alloy substrates with different micropatterns (stripe, square, and ring) composed of n-HA/SF composite were created. Our results demonstrated that the precisely-designed micropatterns of n-HA/SF composite onto Ti and its alloy substrates could be easily achieved by using template-assisted ESD.