Metal release and cell biological compatibility of beta-type Ti-40Nb containing indium

A Review on Nano Ti-Based Oxides for Dark and Photocatalysis: From Photoinduced Processes to Bioimplant Applications

Catalysis on TiO₂ nanomaterials in the presence of H₂O and oxygen plays a crucial role in the advancement of many different fields, such as clean energy technologies, catalysis, disinfection, and bioimplants. Photocatalysis on TiO₂ nanomaterials is well-established and has advanced in the last decades in terms of the understanding of its underlying principles and improvement of its efficiency. Meanwhile, the increasing complexity of modern scientific challenges in disinfection and bioimplants requires a profound mechanistic understanding of both residual and dark catalysis. Here, an overview of the progress made in TiO₂ catalysis is given both in the presence and absence of light. It begins with the mechanisms involving reactive oxygen species (ROS) in TiO₂ photocatalysis. This is followed by improvements in their photocatalytic efficiency due to their nanomorphology and states by enhancing charge separation and increasing light harvesting. A subsection on black TiO₂ nanomaterials and their interesting properties and physics is also included. Progress in residual catalysis and dark catalysis on TiO₂ are then presented. Safety, microbicidal effect, and studies on Ti-oxides for bioimplants are also presented. Finally, conclusions and future perspectives in light of disinfection and bioimplant application are given.

Rolled-Up Metal Oxide Microscaffolds to Study Early Bone Formation at Single Cell Resolution

Titanium and its alloys are frequently used to replace structural components of the human body due to their high mechanical strength, low stiffness, and biocompatibility. In particular, the use of porous materials has improved implant stabilization and the promotion of bone. However, it remains unclear which material properties and geometrical cues are optimal for a proper osteoinduction and osseointegration. To that end, transparent tubular microscaffolds are fabricated, mimicking the typical pores of structural implants, with the aim of studying early bone formation and cell-material interactions at the single cell level. Here, a β-stabilized alloy Ti-45Nb (wt%) is used for the microscaffold's fabrication due to its elastic modulus close to that of natural bone. Human mesenchymal stem cell migration, adhesion, and osteogenic differentiation is thus investigated, paying particular attention to the CaP formation and cell-body crystallization, both analyzed via optical and electron microscopy. It is demonstrated that the developed platform is suited for the long-term study of living single cells in an appropriate microenvironment, obtaining in the process deeper insights on early bone formation and providing cues to improve the stability and biocompatibility of current structural implants.