Biomedical titanium alloys with Young’s moduli close to that of cortical bone, i.e., low Young’s modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti–29Nb–13Ta–4.6Zr referred to as TNTZ, which is highly expected to be used as a biomaterial for implants replacing failed hard tissue. Furthermore, to satisfy the demands from both patients and surgeons, i.e., a low Young’s modulus of the whole implant and a high Young’s modulus of the deformed part of implant, titanium alloys with changeable Young’s modulus, which are also β-type titanium alloys, for instance Ti–12Cr, have been developed. In this review article, by focusing on TNTZ and Ti–12Cr, the biological and mechanical properties of the titanium alloys with low Young’s modulus and changeable Young’s modulus are described. In addition, the titanium alloys with shape memory and superelastic properties were briefly addressed. Surface modifications for tailoring the biological and anti-wear/corrosion performances of the alloys have also been briefly introduced.

Bacterial adhesion and biofilm formation are ubiquitous undesirable phenomena in the marine industry and the medical industry, usually causing economic losses and serious health problems. Numerous efforts have been made to reduce bacterial adhesion and subsequent biofilm formation, most of which are based on the release of toxic biocides from coatings or substrates. In recent years, surface topography has been found to substantially influence the interaction between bacteria and surfaces. This review summarizes previous work dedicated in searching for the relationship between bacterial adhesion and surface topography in the last eight years, as well as the proposed mechanisms by which surface topographic features interact with bacterial cells. Next, various natural and artificial surfaces with bactericidal surface topography along with their bactericidal mechanisms and efficiency are introduced. Finally, the technologies for constructing antibacterial surfaces are briefly summarized.

Regardless of its successful clinical applications, load-bearing implant applications of hydroxyapatite (HA) remain problematic due to its intrinsic property limitations. Recent findings of the promising biocompatibility of graphene imply the possibilities of it being potentially used as additives for HA-based composites with enhanced mechanical properties. Here we report HA–reduced graphite oxide nanocomposites synthesized by a liquid precipitation approach followed by spark plasma sintering consolidation. The reduced graphite oxide (rGO) consisted of 2–6 layers of graphene. Rod-like HA grains with the dimensions of ∼9 nm in diameter and 20–45 nm in length exhibited oriented nucleation and epitaxial growth on graphene flakes. The (300) plane of HA crystals formed a coherent interfacial bond with the graphene wall and the section of the graphene sheet built a strong interface with the (002) plane of HA crystals. These structural features gave rise to enhanced densification and precluded grain growth of HA in the spark plasma sintered pellets. Fracture toughness of the HA–rGO composites reached 3.94 MPa m^1/2, showing a 203% increase compared to pure HA. Crack deflection, crack tip shielding and crack bridging at the HA–rGO interfaces were disclosed as the major strengthening regimes in the composites. The enhanced mechanical properties together with the improved proliferation and ALP activity of the human osteoblast cells suggest a great potential of the composites for biomedical applications.

There have been ever-growing demands for disinfection of water and air in recent years. Efficient, eco-friendly, and cost-effective methods of disinfection for pathogens are vital to the health of human beings. The photocatalysis route has attracted worldwide attention due to its highly efficient oxidative capabilities and sustainable recycling, which can be used to realize the disinfection purposes without secondary pollution. Though many studies have comprehensively reviewed the work about photocatalytic disinfection, including design and fabrication of photocatalytic coatings, inactivation mechanisms, or practical applications, systematic reviews about the disinfection photocatalysis coatings from fabrication to effort for practical use are still rare. Among different ways of fabricating photocatalytic materials, thermal spray is a versatile surface coating technique and competitive in constructing large-scale functional coatings, which is a most promising way for the future environmental purification, biomedical and life health applications. In this review, we briefly introduced various photocatalytic materials and corresponding inactivation mechanisms for virus, bacteria and fungus. We summarized the thermal-sprayed photocatalysts and their antimicrobial performances. Finally, we discussed the future perspectives of the photocatalytic disinfection coatings for potential applications. This review would shed light on the development and implementation of sustainable disinfection strategies that is applicable for extensive use for controlling pathogens in the near future.