NIR-Reflective and Hydrophobic Bio-Inspired Nano-Holed Configurations on Titanium Alloy

BELÉN, FEDERICO; A. NOEL GRAVINA; MARCELO FABIAN PISTONESI; JUAN M. RUSO; NICOLÁS A. GARCÍA; FERNANDO DANIEL PRADO; PAULA V. MESSINA

ACS APPLIED MATERIALS & INTERFACES

AMER CHEMICAL SOC

Lugar: Washington; Año: 2022 vol. 14 p. 5843 - 5855

1944-8244

Near infrared radiation (NIR) plays an important role in guided external stimulus therapies; its application in bone-related treatments is becoming more and more frequent. Therefore, metallic biomaterials that exhibit skills activated by NIR become a promise for further orthopaedic procedures. In this work, we present an adapted electroforming approach to attain a biomorphic nano-holed TiO2 coating on Ti6Al4V alloy. Throughout a precise control of the anodization conditions, structures revealed the formation of localized nano-pores arranged in a periodic assembly. This specific organization provoked higher stability against thermal oxidation and precise hydrophobic wettability behaviour according to Cassie?Baxter?s model; both characteristics are a prerequisite to ensure a favourable biological response in an implantable structure for guided bone regeneration. In addition, the periodically arranged sub-wavelength-sized unit cell on the metallic-dielectric structure exhibits a peculiar optical response which results in higher NIR reflectivity. Accordingly, we have proved that this effect enhances the efficiency of the scattering processes and provokes a significant improvement of light confinement producing a spontaneous NIR fluorescence emission. The combination of the already favourable mechanical and biocompatibility properties of Ti6Al4V, along with a suitable thermal stability, wetting and electro-optical behaviour opens a promising path towards strategic bone therapeutic procedures.