Striped, bioactive Ce-TiO₂ materials with peroxynitrite-scavenging activity

Controlling aligned fiber micro-architectures to simulate the extracellular matrix for inducing important biological functions is a key challenge with regard to successful tissue regeneration. Here we present a bottom-up microemulsion-mediated strategy to obtain highly bioactive and biocompatible, striped Ce-TiO₂ nano-crystalline superstructures with ONOO^- scavenging activity. The employment of a bulkier organic ceria precursor in the material synthesis has several concurrent effects: (I) influencing the interfacial microemulsion droplet elasticity to create an aligned distribution of prismatic anatase nanoparticles causing the final lined morphology, (II) stabilizing the anatase active phase in a fine dispersed state and improving its resistance to the thermal anatase-rutile conversion, (III) indirectly favoring the rapid formation on the material surface of a hydroxyapatite layer composed of sphere-like globules of 3-5 μm in diameter essential for bone-bonding, and finally (IV) accelerating the ONOO^- degradation into less harmful species NO₂ ^- and O₂.