Building biointegration of Fe<sub>2</sub>O<sub>3</sub>-FeOOH coated titanium implant by regulating NIR irradiation in an infected model.

Xue, Yang; Chen, Jun; Ding, Tiexin; Mao, Mengting; Zhu, Shengbo; Zhou, Jianhong; Zhang, Lan; Han, Yong · Bioact Mater · 2022

basic_science · Level V

Where this comes from

Abstract

Killing bacteria, eliminating biofilm and building soft tissue integration are very important for percutaneous implants which service in a complicated environment. In order to endow Ti implants with above abilities, multifunctional coatings consisted of Fe<sub>2</sub>O<sub>3</sub>-FeOOH nanograins as an outer layer and Zn doped microporous TiO<sub>2</sub> as an inner layer were fabricated by micro-arc oxidation, hydrothermal treatment and annealing treatment. The microstructures, physicochemical properties and photothermal response of the coatings were observed; their antibacterial efficiencies and cell response <i>in vitro</i> as well as biofilm elimination and soft tissue integration <i>in vivo</i> were evaluated. The results show that with the increased annealing temperature, coating morphologies didn't change obviously, but lattices of β-FeOOH gradually disorganized into amorphous state and rearranged to form Fe<sub>2</sub>O<sub>3.</sub> The coating annealed at 450 °C (MA450) had nanocrystallized Fe<sub>2</sub>O<sub>3</sub> and β-FeOOH. With a proper NIR irradiation strategy, MA450 killed adhered bacteria efficiently and increased fibroblast behaviors via up-regulating fibrogenic-related genes <i>in vitro</i>; in an infected model, MA450 eliminated biofilm, reduced inflammatory response and improved biointegration with soft tissue. The good performance of MA450 was due to a synergic effect of photothermal response and released ions (Zn<sup>2+</sup> and Fe<sup>3+</sup>).