A nanoengineered coating with dual antioxidant and immunomodulatory functions on titanium implants for osteoregeneration in osteoporosis.

The exogenous bacterial infection and formation of biofilm on the surface of titanium implants can affect the adhesion, proliferation, and differentiation of cells associated with osteogenesis, ultimately leading to surgical failure. This study focuses on two critical stages for biofilm formation: i) bacterial adhesion and aggregation, ii) growth and proliferation. The titanium with well-organized titania nanotube arrays is first modified by nitrogen dopants, then loaded with CuFeSe2 nanoparticles to form a p-n heterojunction. Such heterojunction can effectively separate the electrons and holes generated by CuFeSe2 under NIR excitation, where CuFeSe2 serves as an electron acceptor from adherent bacteria, thus disrupting the respiratory chain and eventually affecting the metabolism. Combined with the released ions in solution and photothermal effect, the formation of bacterial biofilm on the surface of titanium implants is prevented on both stages.

Osteoporosis is a major challenge to oral implants, and this study focused on improving the osseointegration ability of titanium (Ti) implants in osteoporosis environment via surface modification, including doping of strontium ion and preparation of nanoscale surface feature. Our previous studies have shown that strontium (Sr) ions can enhance osteogenic activity. Therefore, we aimed to comprehensively evaluate the effect of hydrothermal treatment of Sr-doped titanium implant coating on bone-binding properties in the microenvironment of osteoporosis in this study. We fabricated Sr-doped nanocoating (AHT-Sr) onto the surface of titanium implants via hydrothermal reaction. The rough Sr-doping had good biological functions and could apparently promote osteogenic differentiation of osteoporotic bone marrow mesenchymal stem cells (OVX-BMSCs). Most importantly, AHT-Sr significantly promoted bone integration in the osteoporosis environment. This study provides an effective approach to implant surface modification for better osseointegration in an osteoporotic environment.

This study aimed to determine the antibiofilm activity of Mentha longifolia essential oil (EO) against biofilms forming on in-vitro implant surfaces. Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans biofilms were used. Stainless steel and titanium samples were grouped as control, water diluted, no EO addition, and reducing amounts of EO doses. The six microorganisms included in the study were investigated to examine if there were differences between the doses on the implant surfaces. The eradication effect of the EO in samples investigated with electron microscope was classified as 0: none, 1: mild, 2: moderate, and 3: severe. The chemical composition of the EO was determined with gas chromatography. In terms of biofilm formation, no difference was observed between implant surfaces. While S. aureus and C. albicans were observed to be the most susceptible, P. aeruginosa was identified as the most resistant. According to gas chromatography, M. longifolia EO comprised 61.40% carvacrol and 0.28% thymol. In vitro, M. longifolia EO was shown to be effective against gram negative/positive and fungal biofilms forming on the surface of stainless steel and titanium implants.

A dual-functional anti-thrombotic hydrogel coating integrating immunomodulation and surface passivation for vascular implants under inflammatory conditions.

Tantalum and titanium are two of the most popular materials used in dental implants today. These materials are highly biocompatible, durable, and long-lasting, making them ideal for use in dental and maxillofacial implants. The ceramic oxide layer that covers the surface of titanium and tantalum implants (TiO2,TaO2) is formed through an electrochemical growth from the inside of the metal and subsequently altered through heat treatment. The aim of this retrospective study was to evaluate the long-term survival of the oxide ceramic-coated titanium dental implants. The secondary purpose was to evaluate the production process and the cost of the coated tantalum and titanium implants, and to complete these retrospective investigations with the results of our previous work concerning the titanium oxide coating. The structural, physical, and chemical properties as well as the corrosion resistance of the Ti/TiO2 surface were investigated; XPS, SIMS, and XRD techniques were used. Patients who received tantalum oxide-coated (Ta/TaO2) dental implants, titanium oxide-coated (Ti/TiO2) dental implants, or titanium oxide-coated (Ti/TiO2) osteosynthesis plates for rehabilitation at the Department of Oro-Maxillofacial Surgery and Stomatology, Semmelweis University between 1995 and 2005 were included in this retrospective study. Data collection was performed between June 2021 and December 2021. The cost of the tantalum implant was 25 times that of the titanium implant. Only 21 implants were inserted in 10 patients. The survival rate (min. 16 years) was 95%. Twelve patients with a total of sixty-four TiO2-coated implants were observed. The mean implant survival rate was 95%. Our conclusion was that, regardless of the shape of the implant, the Ti/TiO2 coating proved its excellent durability over the years. The “tantalum issue” is increasingly relevant nowadays, since instead of implants made of pure tantalum metal, implants with a porous tantalum surface have come to the fore.

A new approach to replace antibiotics with natural pigment derivatives: Surface modification on the titanium implants

Titanium and its alloys are widely used in orthopedic implant materials due to their excellent mechanical properties and good biocompatibilities. However, titanium lacks biological activity and is prone to complications, such as loosening and sinking after implantation. Modifying the surface of titanium can improve its biological activity. In this study, we prepared a cobalt–titania (Co–TiO2) coating on a titanium surface by means of micro-arc oxidation technology. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron energy spectrometry (XPS) and automatic scratch tests were used to check the bond strength of the coating. The surface morphology and structure of the modified coating were characterized; the results showed that when the micro-arc oxidation electrolyte solution contained cobalt gluconate, cobalt was successfully introduced into the titanium surface, the coating exhibited a porous morphology, the elemental cobalt was evenly distributed in the coating, and the introduced cobalt did not change the surface morphology and phase composition of the coating. The scratch tests showed that the coating was strongly bonded with the substrate. In conclusion, Co–TiO2 coatings can be prepared on the surfaces of titanium implants by micro-arc oxidation. The coatings showed good surface characteristics and potential clinical application value.

Using laser etched-array periodic structure surface to construct silver loaded titanium implants with combined efficient antibacterial and osteogenic properties

The effect of different oxidizing ions on hydrogen peroxide treatment of titanium dental implant

To improve the biological activities of titanium implant surfaces and promote efficient early bone formation, the formation of bioactive coatings that promote bone formation on titanium implant surfaces is currently an important area of research. In this study, we prepared a zinc-doped porous coating (Zn-PEO) on a titanium alloy surface via plasma electrolytic oxidation. The surface characteristics of the samples were evaluated with field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), profilometry, static contact angles and nanoscratch studies. The slow release of zinc from the coating was detected with inductively coupled plasma‒mass spectrometry (ICP‒MS). The corrosion resistances of the samples were evaluated via electrochemical studies. On this basis, we evaluated the biocompatibility and biological activity of the sample through in vitro cell experiments. The results confirmed that a Zn-PEO coating was successfully prepared on the surface of the titanium alloy; it exhibited a porous micro/nanomorphology, and the coating and the substrate were tightly bound. The coating increased the roughness of the titanium surface and improved the wear and corrosion resistance. More importantly, the coating promoted adhesion, proliferation, differentiation and mineralization of bone marrow mesenchymal stem cells and had good biological activity. Therefore, Zn-PEO coatings with porous structures were prepared on the surfaces of titanium implants through plasma electrolytic oxidation. The Zn-PEO coating exhibited good surface properties and biological activity and has good application prospects.

Bioinspired lipid droplets nanoplatform for periodontitis therapy: Integrated antibacterial, mitochondrial repair, and immunomodulatory functions.

Diabetic wounds, characterized by delayed healing and susceptibility to infection, pose a significant clinical challenge. Glabridin (GLD), a natural product, has the potential to promote wound repair, but its application is hindered by poor solubility and low photostability. This study developed a novel adhesive deep eutectic gel (eutectogel) by combining a deep eutectic solvent (DES) formed from sulfobutyl ether-β-cyclodextrin (SBE-β-CD) and levulinic acid (Lev) with chitosan (CS) for the efficient delivery of GLD. This system integrates DES with CS through supramolecular interactions, simultaneously addressing the solubility and photostability issues of GLD. The DES not only acts as a solubilizer but also serves as a dynamic crosslinker within the gel network, imparting favorable mechanical properties. The resulting GLD/CS/DES gel formed a flexible patch, enabling sustained GLD release for over 10 days and effectively protecting GLD from photodegradation. In vitro antibacterial assays demonstrated over 99% efficacy against S. aureus and E. coli, with the mechanism of action linked to disruption of bacterial cell membrane integrity. In an infected diabetic wound model, the GLD/CS/DES gel significantly accelerated wound healing, achieving a wound closure rate of 94.3% by day 21. Mechanistic studies revealed that the GLD/CS/DES gel ameliorated the immune microenvironment, promoted angiogenesis, and tissue regeneration by scavenging reactive oxygen species (ROS), inhibiting the nuclear factor kappa-B (NF-κB) signaling pathway, and facilitating macrophage polarization from the pro-inflammatory M1 phenotype to the reparative M2 phenotype. In summary, the GLD/CS/DES gel developed in this study integrates antibacterial, immunomodulatory, and pro-angiogenic functions, offering a promising therapeutic strategy for the management of infected diabetic wounds.

Capillary endothelia and pericytes form a close morphological arrangement allowing pericytes to regulate capillary blood flow, in addition to contributing to vascular development and support. Vascular changes associated with oxidative stress are implicated in important pathologies in developing whiter matter, but little is known about the vascular unit in white matter of the appropriate age or how it responds to oxidative stress. We show that the ultrastructural arrangement of post-natal day 10 (P10) capillaries involves the apposition of pericyte somata to the capillary inner basement membrane and penetration of pericyte processes onto the abluminal surface where they form close connections with endothelial cells. Some pericytes have an unusual stellate morphology, extending processes radially from the vessel. Reactive oxygen species (ROS) were monitored with the ROS-sensitive dye 2',7'-dichlorofluorescin (DCF) in the endothelial cells. Exposure to exogenous ROS (100 μm H(2) O(2) or xanthine/xanthine oxidase), evoked an elevation in intracellular ROS that declined to baseline during the ongoing challenge. A second challenge failed to evoke an intracellular ROS rise unless the nerve was rested for > 4 h or exposed to very high levels of exogenous ROS. Exposure to a first ROS challenge prior to loading with DCF also prevented the intracellular ROS rise from a second challenge, proving that dye washout during exposure to ROS is not responsible for the loss of a second response. Perfusion with 30 μm extracellular Ca(2+) or the voltage-gated Ca(2+) antagonist diltiazem partially prevented this rapid scavenging of intracellular ROS, but blocking either catalase or glutathione peroxidase did not. The phenomenon was present over a range of post-natal ages and may contribute to the high ROS-tolerance of endothelial cells and act to limit the release of harmful ROS onto neighbouring pericytes.

Osseointegration of dental implants in rabbit bone with low mineral density

The success of titanium dental implants relies on osseointegration, the load-bearing connection between bone tissue and the device that, in contact osteogenesis, comprises the deposition of bony cement line matrix onto the implant surface. Titanium dioxide nanotubes (NTs) are considered a promising surface for improved osseointegration, yet the mechanisms of cement line integration with such features remains elusive. Herein, we illustrate cement line deposition into NTs on the surface of titanium implants with two underlaying microstructures: a machined surface or a blasted/acid etched surface placed in the tibiae of Wistar rats. After retrieval, scanning electron microscopy of tissue reflected from the implant surface indicated minimal incursion of the cement line matrix into the NTs. To investigate this further, focused ion beam was utilized to prepare cross-sectional samples that could be characterized using scanning transmission electron microscopy. The cement line matrix covered NTs regardless of underlying microstructure, which was further confirmed by elemental analysis. In some instances, cement line infiltration into the NTs was noted, which reveals a mechanism of nanoscale anchorage. This study is the first to demonstrate cement line deposition into titanium NTs, suggesting nano-anchorage as a mechanism for the success of the NT modified surfaces in vivo.