Surface Modification Of Titanium Implants Research Articles

Surface modification of biomedical titanium alloy for hard tissue repair and reconstruction

In biomedical applications, various materials are used, including metals and their alloys, polymers and ceramics. Among them, titanium (Ti) and titanium alloys are widely utilised in implant materials due to their excellent corrosion resistance and high mechanical strength. However, despite these advantages, titanium is biologically inert and does not integrate well with human cells. Therefore, surface modification of titanium implants plays a crucial role in determining the rate of osseointegration and the overall success of the implants. The primary objective of this review is to provide a detailed introduction to surface modification technologies for titanium alloy implants. The aim is to enhance the biological activity, wear resistance, corrosion resistance and antibacterial properties and reduce the release of ions from the implants. By modifying the surface of titanium implants, it is possible to create a more favourable environment for cell adhesion, proliferation and differentiation. Various techniques, such as physical methods (e.g. sandblasting, acid etching) and chemical methods (e.g. surface oxidation, plasma treatment) can be employed to modify the surface properties of titanium implants. These surface modification techniques can enhance the interaction between the implant and the surrounding biological environment, promoting osseointegration and improving the long-term stability of the implant. Additionally, surface modifications can help reduce the release of potentially harmful ions from the implant, minimise bacterial adhesion and improve the overall biocompatibility of the implant. In conclusion, surface modification of titanium alloy implants is a critical aspect of biomedical engineering. By improving the biocompatibility of titanium implants, these modifications contribute to the success and longevity of implants used in hard tissue repair and reconstruction.

Multifunctional Prosthesis Surface: Modification of Titanium with Cinnamaldehyde-Loaded Hierarchical Titanium Dioxide Nanotubes.

Orthopedic prostheses are the ultimate therapeutic solution for various end-stage orthopedic conditions. However, aseptic loosening and pyogenic infections remain as primary complications associated with these devices. In this study, a hierarchical titanium dioxide (TiO2 ) nanotube drug delivery system loaded with cinnamaldehyde for the surface modification of titanium implants, is constructed. These specially designed dual-layer TiO2 nanotubes enhance material reactivity and provide an extensive drug-loading platform within a short time. The introduction of cinnamaldehyde enhances the bone integration performance of the scaffold (simultaneously promoting bone formation and inhibiting bone resorption), anti-inflammatory capacity, and antibacterial properties. In vitro experiments have demonstrated that this system promoted osteogenesis by upregulating both Wnt/β-catenin and MAPK signaling pathways. Furthermore, it inhibits osteoclast formation, suppresses macrophage-mediated inflammatory responses, and impedes the proliferation of Staphylococcus aureus and Escherichia coli. In vivo experiments shows that this material enhances bone integration in a rat model of femoral defects. In addition, it effectively enhances the antibacterial and anti-inflammatory properties in a subcutaneous implant in a rat model. This study provides a straightforward and highly effective surface modification strategy for orthopedic Ti implants.

Preparation of a novel antibacterial magnesium carbonate coating on a titanium surface and its in vitro biocompatibility.

Magnesium-based coatings have attracted great attention in surface modification of titanium implants due to their superior angiogenic and osteogenic properties. However, their biological effects as a carbonate-based constituent remain unrevealed. In this study, magnesium carbonate coatings were prepared on titanium surfaces under hydrothermal conditions and subsequently treated with hydrogen peroxide. Also, their antibacterial activity and in vitro cell biocompatibility were evaluated. The obtained coatings consisted of nanoparticles without cracks and exhibited excellent adhesion to the substrate. X-ray diffraction (XRD) results indicated pure magnesium carbonate coatings formed on the Ti surface after hydrothermal treatment. After hydrogen peroxide treatment, the phase composition of the coatings had no obvious change. Compared to the untreated coatings, the hydrogen peroxide-treated coatings showed increased surface roughness and hydrophilicity. Co-culture with Staphylococcus aureus (S. aureus) demonstrated that the obtained coatings had good antibacterial activity. In vitro cell culture results showed that the hydrogen peroxide-treated coatings enhanced the viability, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). These findings suggest that this MgCO3-based coating exhibits excellent antibacterial performance and osteogenic potential. Based on the above, this study provides a simple method for preparing titanium implants with dual antibacterial and osteogenic capabilities, holding great promise in clinical applications.

Effect of Electrocautery and Laser Treatment on the Composition and Morphology of Surface-Modified Titanium Implants.

The purpose of this study was to investigate the effects of different peri-implantitis treatment methods (Er,Cr:YSGG laser, diode laser, and electrocautery) on various titanium implant surfaces: machined; sandblasted, large-grit, and acid-etched; and femtosecond laser-treated surfaces. Grade 4 titanium (Ti) disks, with a diameter of 10 mm and a thickness of 1 mm, were fabricated and treated using the aforementioned techniques. Subsequently, each treated group of disks underwent different peri-implantitis treatment methods: Er,Cr:YSGG laser (Biolase, Inc., Foothill Ranch, CA, USA), diode laser (Biolase, Inc., Foothill Ranch, CA, USA), and electrocautery (Ellman, Hicksville, NY, USA). Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and wettability were used to characterize the chemical compositions and surfaces of the treated titanium surfaces. Significant changes in surface roughness were observed in both the electrocautery (Sa value of machined surface = 0.469, SLA surface = 1.569, femtosecond laser surface = 1.741, and p = 0.025) and Er,Cr:YSGG laser (Ra value of machined surface = 1.034, SLA surface = 1.380, femtosecond laser surface = 1.437, and p = 0.025) groups. On femtosecond laser-treated titanium implant surfaces, all three treatment methods significantly reduced the surface contact angle (control = 82.2°, diode laser = 74.3°, Er,Cr:YSGG laser = 73.8°, electrocautery = 76.2°, and p = 0.039). Overall, Er,Cr:YSGG laser and electrocautery treatments significantly altered the surface roughness of titanium implant surfaces. As a result of surface composition after different peri-implantitis treatment methods, relative to the diode laser and electrocautery, the Er,Cr:YSGG laser increased oxygen concentration. The most dramatic change was observed after Er:Cr;YSGG laser treatment, urging caution for clinical applications. Changes in surface composition and wettability were observed but were not statistically significant. Further research is needed to understand the biological implications of these peri-implantitis treatment methods.

Surface modification of titanium implants with Mg-containing coatings to promote osseointegration.

Titanium (Ti) and Ti alloys are commonly used in dental implants, which have good biocompatibility, mechanical strength, processability, and corrosion resistance. However, the surface inertia of Ti implants leads to delayed integration of Ti and new bone, as well as problems such as aseptic loosening and inadequate osseointegration. Magnesium ions (Mg) can promote bone regeneration, and many studies have used Mg-containing materials to modify the Ti implant surface. This systematic review summarizes the methods, effects, and clinical applications of surface modification of Ti implants with Mg-containing coatings. Database collection was completed on Janury 1, 2023, and a total of 29 relevant studies were ultimately included. Mg can be compounded with different materials and coated to the surface of Ti implants using different methods. On the one hand, the surface roughness of implants increases with the addition of Mg-containing coatings, which is thought to have an impact on the osseointegration of the implant. On the other hand, Mg ions promote cell attachment through binding interactions between the integrin family and FAK-related signaling pathways. And Mg ions could induce osseointegration by activating PI3K, Notch, ERK/c-Fos, BMP-4-related signaling pathways and TRPM7 protein channels. In vitro and in vivo experiments have shown that Mg-containing coatings promote cell adhesion and osteogenic differentiation. In addition, Mg-containing implants have been used in clinical trials to assess various outcomes, and the results have shown that there is no synergistic effect between blasting and Mg incorporation, which may be due to the short observation periods. STATEMENT OF SIGNIFICANCE: : As a commonly used dental implant material, the surface inertia of titanium (Ti) implants leads to delayed osseointegration, which may result in aseptic loosening or insufficient osseointegration. Magnesium ions (Mg), known for promoting bone regeneration, have been extensively studied to modify the surface of Ti implants. This paper provides a systematic review of the literature on the surface modification of Ti implants with Mg-containing compounds, highlighting the effects of Mg-containing coatings on the surface properties of Ti implants and associated mechanisms. Furthermore, this study presents the clinical prospects of Mg-modified implants and discusses the challenges that need to be addressed for successful application.

Silane-coupled chitosan-cyclodextrin/rosmarinic acid-zinc complex coating improves the osseointegration of titanium implants in high-glucose environments

The osseointegration of titanium implants in a diabetic microenvironment is greatly limited by mitochondrial dysfunction, increased reactive oxygen species, and reduced osteoblastic activity. Rosmarinic acid (RA), a polyphenolic molecule with powerful antioxidant and anti-inflammatory properties, can chelate Zn ions to form the RA-Zn complex. This study aimed to develop a local drug delivery system on the titanium surface using this complex. Carboxymethyl-β-cyclodextrin and chitosan were used to encapsulate the complex, and the coupling agent silane triethoxysilylpropyl succinic anhydride was used to covalently immobilize the chitosan molecules after binding to the alkali-heat treated titanium surface. A coating with good hydrophilic properties, adhesive strength, and frictional resistance, which allowed for the controlled and sustained release of RA-Zn, was successfully constructed. The coating had good biocompatibility and promoted the adhesion and proliferation of mouse preosteoblasts (MC3T3-E1) under high-glucose conditions. It upregulated the expression levels of osteogenic genes, increased the secretion of osteogenic-related proteins, and promoted cell mineralization. Furthermore, it improved the mitochondrial dynamics and restored mitochondrial dysfunction under high-glucose conditions. This study proposes a new titanium implant surface modification strategy to deliver biological components with antioxidant and osteogenic activities to target sites.

Progress in Surface Modification of Titanium Implants by Hydrogel Coatings.

Although titanium and titanium alloys have become the preferred materials for various medical implants, surface modification technology still needs to be strengthened in order to adapt to the complex physiological environment of the human body. Compared with physical or chemical modification methods, biochemical modification, such as the introduction of functional hydrogel coating on implants, can fix biomolecules such as proteins, peptides, growth factors, polysaccharides, or nucleotides on the surface of the implants, so that they can directly participate in biological processes; regulate cell adhesion, proliferation, migration, and differentiation; and improve the biological activity on the surface of the implants. This review begins with a look at common substrate materials for hydrogel coatings on implant surfaces, including natural polymers such as collagen, gelatin, chitosan, and alginate, and synthetic materials such as polyvinyl alcohol, polyacrylamide, polyethylene glycol, and polyacrylic acid. Then, the common construction methods of hydrogel coating (electrochemical method, sol-gel method and layer-by-layer self-assembly method) are introduced. Finally, five aspects of the enhancement effect of hydrogel coating on the surface bioactivity of titanium and titanium alloy implants are described: osseointegration, angiogenesis, macrophage polarization, antibacterial effects, and drug delivery. In this paper, we also summarize the latest research progress and point out the future research direction. After searching, no previous relevant literature reporting this information was found.

Surface Modification of Titanium Implants by Metal Ions and Nanoparticles for Biomedical Application.

Implant surface modification can improve osseointegration and reduce peri-implant inflammation. Implant surfaces are modified with metals because of their excellent mechanical properties and significant functions. Metal surface modification is divided into metal ions and nanoparticle surface modification. These two methods function by adding a finishing metal to the surface of the implant, and both play a role in promoting osteogenic, angiogenic, and antibacterial properties. Based on this, the nanostructural surface changes confer stronger antibacterial and cellular affinity to the implant surface. The current paper reviews the forms, mechanisms, and applications of nanoparticles and metal ion modifications to provide a foundation for the surface modification of implants.

Ti6Al4V coatings on titanium samples by sputtering techniques: Microstructural and mechanical characterization

Although titanium is widely used as biomaterial, the control of the interface properties between its surface and the surrounding physiological environment (like bone, other tissues or biofluids) results crucial to achieve a successful osseointegration and good biomechanical and functional performance. In this work, commercially pure titanium (Grade IV) discs obtained by conventional powder metallurgy were coated with 1–3 µm of Ti6Al4V (Grade V) alloy using DC-pulsed or high-power impulse magnetron sputtering (HiPIMS) technique with the aim of improving their biomedical performance. SEM, confocal microscopy, X-ray diffraction, nanoindentation and wetting measurements are used to evaluate the bio-interface role of the titanium-coated implants. Conformal Ti6Al4V coatings with controlled nano-roughness can be deposited with enhanced mechanical (H = 5–8 GPa; E = 140–160 GPa) and hydrophobic properties thanks to a dense columnar structure. The increased Ti-O bonding at the interface helps to prevent the corrosion due to the formation of a surface passivation layer. Particularly in the case of the HiPIMS process, the surface modification of titanium implants (chemistry, morphology and structure) appears as an effective strategy for satisfying the biomedical requirements and functionality, with enhanced mechanical properties and nanostructuration for prevention of bacteria colonization.

Novel Strategy for Surface Modification of Titanium Implants towards the Improvement of Osseointegration Property and Antibiotic Local Delivery

The topography and chemical composition modification of titanium (Ti) implants play a decisive role in improving biocompatibility and bioactivity, accelerating osseointegration, and, thus, determining clinical success. In spite of the development of surface modification strategies, bacterial contamination is a common cause of failure. The use of systemic antibiotic therapy does not guarantee action at the contaminated site. In this work, we proposed a surface treatment for Ti implants that aim to improve their osseointegration and reduce bacterial colonization in surgery sites due to the local release of antibiotic. The Ti discs were hydrothermally treated with 3M NaOH solution to form a nanostructured layer of titanate on the Ti surface. Metronidazole was impregnated on these nanostructured surfaces to enable its local release. The samples were coated with poly(vinyl alcohol)-PVA films with different thickness to evaluate a possible control of drug release. Gamma irradiation was used to crosslink the polymer chains to achieve hydrogel layer formation and to sterilize the samples. The samples were characterized by XRD, SEM, FTIR, contact angle measurements, "in vitro" bioactivity, and drug release analysis. The alkaline hydrothermal treatment successfully produced intertwined, web-like nanostructures on the Ti surface, providing wettability and bioactivity to the Ti samples (Ti + TTNT samples). Metronidazole was successfully loaded and released from the Ti + TTNT samples coated or not with PVA. Although the polymeric film acted as a physical barrier to drug delivery, all groups reached the minimum inhibitory concentration for anaerobic bacteria. Thus, the surface modification method presented is a potential approach to improve the osseointegration of Ti implants and to associate local drug delivery with dental implants, preventing early infections and bone failure.

Antibacterial Coatings for Titanium Implants: Recent Trends and Future Perspectives.

Titanium and its alloys are widely used as implant materials for biomedical devices owing to their high mechanical strength, biocompatibility, and corrosion resistance. However, there is a significant rise in implant-associated infections (IAIs) leading to revision surgeries, which are more complicated than the original replacement surgery. To reduce the risk of infections, numerous antibacterial agents, e.g., bioactive compounds, metal ions, nanoparticles, antimicrobial peptides, polymers, etc., have been incorporated on the surface of the titanium implant. Various coating methods and surface modification techniques, e.g., micro-arc oxidation (MAO), layer-by-layer (LbL) assembly, plasma electrolytic oxidation (PEO), anodization, magnetron sputtering, and spin coating, are exploited in the race to create a biocompatible, antibacterial titanium implant surface that can simultaneously promote tissue integration around the implant. The nature and surface morphology of implant coatings play an important role in bacterial inhibition and drug delivery. Surface modification of titanium implants with nanostructured materials, such as titanium nanotubes, enhances bone regeneration. Antimicrobial peptides loaded with antibiotics help to achieve sustained drug release and reduce the risk of antibiotic resistance. Additive manufacturing of patient-specific porous titanium implants will have a clear future direction in the development of antimicrobial titanium implants. In this review, a brief overview of the different types of coatings that are used to prevent implant-associated infections and the applications of 3D printing in the development of antibacterial titanium implants is presented.

Micro-arc oxidation preparation of a ZnO-Se composite coating on titanium with anti-oxidation and anti-bacterial potentials for osteomyelitis control

• ZnO-Se composite coating was fabricated on titanium surface via MAO processing. • Presence of Se in coating can scavenge ROS by three times as compared to control. • ZnO-Se composite coating could inhibit S. aureus adherence by 81.02%. Osteomyelitis is a severe bone infection with a high rate of relapse. Given the fact that occurrence/relapse of osteomyelitis is associated with the presence of foreign bodies, it is highly desired to develop orthopedic implant with long-term anti-infection and anti-inflammation properties. In current work, zinc oxide-selenium (ZnO-Se) composite coatings were fabricated on titanium surface via micro-arc oxidation (MAO) processing purposed to generate integrated functional surface for osteomyelitis control. On one hand, the combination of ZnO and Se could inhibit the adherence of S. aureus , which accounts for majority of osteomyelitis occurrence. On the other hand, the anti-oxidation significance of Se was purposed to reduce inflammation severity. The subsequent material characterizations, DPPH radicals scavenge test, cell culture and anti-bacterial test confirmed the potential of ZnO-Se MAO coating in osteomyelitis control, thereby providing a facile option for titanium implant surface modification.

Bi-functionalization of titanium with a mixture of peptides for improving its osteogenic and antibacterial activity

Poor osteointegration and implant infection are two of the main causes that hinder the success of clinical implants. In order to enhance the osteogenesis and antibacterial activity of titanium, BFP-1 and GL13K peptides were immobilized on the surface of micro/nanostructured titanium using dopamine as a coupling mechanism. Successful construction of BFP-1 and GL13K peptides on the micro/nanostructured titanium surfaces was demonstrated by several material characterization methods including scanning electron microscopy (SEM), atomic force microscope (AFM), water contact angle measurements and X-ray photoelectron spectroscopy (XPS). The micro/nanostructured titanium modified with BFP-1 and GL13K peptides promoted osteoblast differentiation as demonstrated by cell staining, cell viability, alkaline phosphatase activity, mineralization detection and qRT-PCR of osteogenesis-related genes. The in vitro study exhibited antibacterial properties after culturing S. aureus and E. coli on micro/nanostructured titanium modified with BFP-1 and GL13K peptides for 6 h and 24 h. This study demonstrates that surface-modified titanium implants can simultaneously promote bone growth and provide antibacterial capabilities.

MOF-derived CuO@ZnO modified titanium implant for synergistic antibacterial ability, osteogenesis and angiogenesis

Surface modification of titanium implants with antibacterial, osteogenic and even angiogenic capabilities are essential to enhance their clinical applicability. Herein, metal-organic framework (MOF) derived CuO@ZnO composite was grafted onto the polydopamine (PDA) modified titanium alloy to achieve vascularized bone regeneration. The CuO@ZnO-coated titanium effectively inhibits the formation of bacterial biofilms and the sterilization rate of Staphylococcus aureus (S. aureus) reaches 99%. Benefitting from the intrinsic porous architecture of MOFs, the Zn2+ and Cu2+ could be controllably released to facilitate the production of excess intracellular reactive oxygen species (ROS) inside the bacteria, which ensures the excellent antibacterial performance of the composite coating. The CuO@ZnO-coated titanium also exhibits good cytocompatibility, effectively promotes the adhesion and proliferation of the human bone marrow mesenchymal stem cells (hBMSCs) and reduces the level of the cell apoptosis. The up-regulated expression of the osteogenesis-related genes and the superior extracellular matrix mineralization reveals that the CuO@ZnO coating possesses fantastic osteoinductive properties. In addition, the transwell and tube formation assays of the human umbilical vein endothelial cells (HUVECs) suggest the superior angiogenesis ability of the CuO@ZnO-coated titanium. The released Cu2+ stimulated the angiogenesis of the HUVECs in vitro by up-regulating the expression of the vascular endothelial growth factor (VEGF). These findings will provide new insight into the development of multifunctional titanium implants for clinical applications.

199. A novel and scalable antimicrobial surface modification technology to prevent and mitigate implant related surgical site infections: an in-vivo safety and efficacy study

<h3>BACKGROUND CONTEXT</h3> Despite significant technological advancements in material science, a high level of hand-hygiene and systematic use of antiseptics and antibiotics, surgical site infections (SSI) are still to date the number one complication seen after surgery in the United States. Methicillin-resistant Staphylococcus aureus (MRSA) is the largest purveyor of health care-acquired infections (HCAI) and is responsible for significant morbidity and mortality. <h3>PURPOSE</h3> This study aimed to demonstrate the in-vivo safety and antibacterial efficacy of non-eluting titanium implants covalently bound with a novel broad-spectrum biocidal quaternary ammonium compound (DBG21) against MRSA biofilm. <h3>STUDY DESIGN/SETTING</h3> Subcutaneous MRSA infection mouse model comparing the antimicrobial efficacy of untreatedversusDBG21-treated titanium alloy discs. A separate comparative safety study was performed in the absence of infection. <h3>PATIENT SAMPLE</h3> Sixty-five 11-week-old balb/c mice. <h3>OUTCOME MEASURES</h3> Efficacy study: Number of adherent bacteria on implants (CFU) and in the surrounding tissue (CFU/g) at days 7 and 14. Safety study: systemic and subacute toxicity (clinical tolerance, blood tests and histology). <h3>METHODS</h3> Efficacy Study: TiAl6V4 discs, 6mm ø, 0.5 mm thick, were activated, dip-coated in a polymer solution, and baked to produce covalently bound DBG21-treated discs. Untreated TiAl6V4 discs were used as controls. All discs underwent subsequent sterilization by 25kGy gamma-irradiation, were implanted either untreated for control mice or DBG21-treated for treated mice, and were challenged with a high-bacterial inoculum of MRSA (ATCC43300) in a well-established subcutaneous infection mouse model (11-week-old balb/c) in the absence of antibiotics. A veterinary ethics committee validated the protocol. Sixty-five mice (33 controls, 32 treated) were included in an antibacterial efficacy study. After implantation of one disc in a posterior subcutaneous pocket and closure of the skin for each mouse, 7 log10CFU (colony forming units) of MRSA were injected through a catheter into the operating site. Mice were sacrificed after either 7 days (18 treated, 18 controls) or 14 days (15 controls, 14 treated) to determine the number of adherent bacteria (biofilm) on implants and in the peri-implant surrounding tissues. Results were expressed respectively as median log10CFU reduction on implants and median log10CFU/g reduction in tissue compared with untreated control mice. The statistical significance (p) was determined using Mann-Whitney tests. Safety Study: Ten mice implanted with either control (5 mice) or DBG-21 treated (5 mice) discs were assessed in a safety study in the absence of infection (ISO 10993-11:2017 for systemic and subacute toxicity including clinical tolerance, blood tests and local histology). <h3>RESULTS</h3> Efficacy Study: At both 7 and 14 days, DBG21-treated implants yielded a significant decrease in MRSA biofilm (respectively 3.6 median log10CFU (99.97%) reduction (p < 0.001) and 1.9 median log10CFU (98.7%) reduction (p = 0.037)) and peri-implant surrounding tissues (respectively 2.7 median log10CFU/g (99.8%) reduction (p < 0.001) and 5.6 median log10CFU/g (99.9997%) reduction (p < 0.001)). At day 7, three treated mice (16.6%) were completely sterilized on both tissue and implant. At day 14, 10 treated mice (71.4%) had sterile peri-implant tissue. Safety Study: There were no significant differences between control and treated mice in terms of clinical scores, blood tests and local histology after up to 11 days from implantation. <h3>CONCLUSIONS</h3> Preventing biofilm formation has been recognized as a key element of SSI prevention. Yet, no biofilm-resistant titanium implants are available in clinical practice to prevent and mitigate the burden of SSIs. This small animal safety and efficacy trial suggests that DBG-21 is a promising candidate for antimicrobial surface modification of titanium implants. <h3>FDA DEVICE/DRUG STATUS</h3> DBG21 antimicrobial surface modification (Not approved for this indication).

Facile fabrication of nanoporous structure on β titanium alloy to eliminate stress shielding for bone implant

A TiNb nanoporous structure on the surface of Ti2448 (Ti24Nb4Zr8Sn, wt. %) alloy substrate was successfully fabricated by a combination method of magnetron sputtering and chemical dealloying. Such a nanoporous structure has the characteristics of bicontinuous opening. The elastic modulus of the obtained nanoporous film reached 24 GPa, which is consistent with the elastic modulus of human bone (10–30 GPa). Such a nanoporous structure reduces the modulus of the surface while ensuring the high strength of the alloy. It will effectively eliminate the stress shielding effect of the bone on the implant. This method has promising applications in the surface modification of titanium implants to enhance osseointegration.

Chitosan/poly(4-vinylpyridine) coatings formed on AgNPs-decorated titanium

Electrophoretic deposition (EPD) of chitosan/poly(4-vinylpyridine) (chit/P4VP) coatings on titanium substrates previously decorated with silver nanoparticles (AgNPs) was performed at different content of P4VP in the suspension and different voltage values. The results revealed that the composite coatings were formed, well-adjacent to the titanium substrate, of suitable roughness, hydrophilicity, and corrosion resistance. The voltage value and P4VP content had complex effects on coating properties, due to the effects of process parameters on microstructure and adhesion. The best coatings of both chitosan and P4VP were formed at 10 V at 0.1% (w/w) during a one-minute deposition. These pH-sensitive antibacterial coatings may, based on the present results, be recommended for surface modification of titanium implants.

Surface modification of titanium implants by pH-Responsive coating designed for Self-Adaptive antibacterial and promoted osseointegration

The development of responsive antibacterial implants is of high significance for the treatment of implant-associated infections. In this study, a self-adaptive antibacterial Ti-based implant with pH-sensitive coating was flexibly designed and constructed, with the dual functions of antibacterial and promoted osseointegration. The pH-sensitive antibacterial copolymer containing cationic quaternary ammonium salts (QAs) and carboxyl groups was firstly synthesized. Then, the prepared copolymer was coated on the surface of Ti metal by a simple layer-by-layer (LBL) self-assembly method to construct an antibacterial coating. The surface charge reversal was caused by the acidic microenvironment induced by the infected bacteria. The positively charged QAs possessed excellent antibacterial property against E. coli and S. aureus in vitro. The negatively charged carboxyl groups promoted the adhesion, proliferation and osteogenic differentiation of MC3T3-E1 cells in vitro. And the results of a S. aureus infection rat model further confirmed that the coated screws possessed good abilities of antibacterial and anti-inflammatory of implantation, and showed good osteointegration performance compared with the control ones. This strategy of self-adaptive antibacterial coating will provide a potential application for the prevention of Ti implant-associated bacterial infections.

Surface modification of titanium implants with micro–nano-topography and NIR photothermal property for treating bacterial infection and promoting osseointegration

Surface modification of titanium implants with micro–nano-topography and NIR photothermal property for treating bacterial infection and promoting osseointegration

Controlled release of dopamine coatings on titanium bidirectionally regulate osteoclastic and osteogenic response behaviors

Bone diseases, for example, osteoporosis, cause excessive differentiation of osteoclasts and decreased bone formation, resulting in imbalance of bone remodeling and poor osseointegration, which can be considered a relative contraindication for titanium implants. Dopamine (DA) might provide a solution to this problem by inhibiting osteoclasts and promoting osteoblasts at different concentrations. However, current commercial implants cannot load bone-active molecules, such as DA. Therefore, this study aimed to develop a surface modification method for implants to achieve a controlled release of DA and enhance the resistance of titanium implants to bone resorption and bone regeneration. DA-loaded alginate-arginine-glycine-aspartic acid (RGD) (AlgR) coatings on a vaterite-modified titanium surface were successfully assembled, which continuously and steadily released DA. In vitro studies have shown that materials showing good biocompatibility can not only inhibit receptor activator of nuclear factor-kappa B (NFκB) ligand (RANKL)-induced osteoclastogenesis but also enhance the adhesion and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The optimal DA-loaded concentration of this bidirectional regulation is 100 μM. Interestingly, DA more effectively attenuated osteoclastogenesis when released in a sustained manner from titanium coatings than it did via traditional, free administration, and the alginate-RGD coating and DA clearly exhibited great synergy. This study provides a design of titanium implant surface modification to improve bone remodeling around implants.