In Situ Construction of Black Titanium Oxide with a Multilevel Structure on a Titanium Alloy for Photothermal Antibacterial Therapy

Abstract

Postsurgical infection of orthopedic fixation materials is considered to be the main cause of fixation failure. To address the problem, clinical treatment often relies on long-term antibiotics, secondary surgery, and so forth, which cause pain and suffering to patients. Constructing a light-responsive surface structure on the implant has attracted widespread attention for the management of postsurgical infections because of its noninvasiveness and controllability. Nevertheless, the application of light-responsive structures on implants is still limited by their unsafety and instability. In this work, a black titanium oxide layer with a multilevel structure and lattice defects was in situ constructed on a titanium alloy through pulsed laser ablation treatment. Under the synergistic effect of the multilevel structure and crystal defects, the surface of the titanium alloy exhibited good near-infrared light-responsive photothermal ability. The black titanium oxide multilevel structure reached high antibacterial efficiencies of about 99.37 and 99.29% against Staphylococcus aureus and Escherichia coli under 10 min near-infrared light irradiation. Furthermore, the black titanium oxide layer possessed similar biocompatibility compared with the titanium alloy. This near-infrared light-responsive photothermal therapy based on the construction of a multilevel structure and introduction of lattice defects provides an effective strategy for clinical postsurgical infections of orthopedic fixation.

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

“…Further, amorphous black TiO 2 can also be synthesized and used for photocatalysis [ 201 ], which is important for applications such as for bone implants. Black TiO 2 was shown to exhibit biocompatibility [ 213 ], regenerative properties [ 214 ], photothermal properties [ 213 , 214 , 215 ], and microbicidal action [ 213 , 215 , 216 , 217 ], among others. As such, black TiO 2 shows promise for cancer treatment [ 214 , 215 ], as a bone implant coating, and for disinfection purposes [ 213 , 215 , 216 , 217 ].…”

“…Black TiO 2 was shown to exhibit biocompatibility [ 213 ], regenerative properties [ 214 ], photothermal properties [ 213 , 214 , 215 ], and microbicidal action [ 213 , 215 , 216 , 217 ], among others. As such, black TiO 2 shows promise for cancer treatment [ 214 , 215 ], as a bone implant coating, and for disinfection purposes [ 213 , 215 , 216 , 217 ]. Similar to TiO 2 , the photo(electro)catalytic disinfection with black TiO 2 nanomaterials is also claimed to occur due to ROS, in particular, superoxide and/or hydroxyl radicals [ 216 , 217 ].…”

“…Black TiO 2 , on the other hand, shows an electrochemical (EC) microbicidal effect which could be of the same disinfection rate as the photocatalytic effect [ 213 ]. Though radicals were not seen in ESR in the dark on black TiO 2 , in comparison to PEC treatment, the EC microbicidal result indicates that light is not necessary for black TiO 2 to display microbicidal action.…”

Iodine-Doped 3D Print Ti Alloy for Antibacterial Therapy on Orthopedic Implants

“…A large body of literature indicates that bacterial infection is one of the main causes of the clinical failure of titanium and titanium alloys as orthopedic implants. , Once bacterial adhesion occurs on the implant surface, bacterial colonies and biofilms will gradually form and disrupt the function of the implant. , Previous studies have shown that the early 4–6 h of bacterial adhesion is essential for long-term resistance to bacterial-associated infections and is particularly important. , …”

Defect Engineering in Biomedical Sciences

“…In the same milieu, Yang and co‐workers developed photoresponsive biomedical grade titanium alloy (Ti 6 Al 4 V) substrates with cauliflower‐like black titanium oxide layer with multilevel structures and lattice defects (contributed by oxygen vacancies and amorphous lattice) for orthopedic applications using pulsed laser ablation treatment. [ 129 ] Such structural aspects and defects allowed for better NIR absorption and promoted the photothermal abilities of the engineered substrates. Besides, these substrates were able to impart efficient bactericidal effects on S. aureus (99.37%) and E. coli (99.29%) via NIR‐induced photothermal effects.…”