Pristine Ti Research Articles

Systematic Design of a Flow-Through Titanium Electrode-Based Device with Strong Oil Droplet Rejection Property for Superior Oil-in-Water Emulsion Separation Performance.

Oily wastewater treatment has been restricted by the existence of stable oil-in-water (O/W) emulsions containing micrometer-sized oil droplets. However, the strong adhesion and stacking of emulsified oil droplets on the surface of current separation media cause serious fouling of the treatment unit and the rapid decline of treatment efficiency. Herein, a novel flow-through titanium (Ti) electrode-based filtration device with remarkable oil droplet rejection property was well designed for the continuously separating O/W emulsion. In contrast to the pristine Ti foam, the permeance of the TiO2 nanoarray-coated Ti foam (NATF) increased from 2538 to 4364 L m-2 h-1 bar-1 through gravity-driven flow. Further, more than ∼70% permeability can be maintained after 6 h of O/W emulsion filtration using the current device, the value of which was markedly higher than that of conventional oil/water separation filters (less than 5%). According to the results of wettability test, the super-oil-repellent surface endowed by this nanoarray structure primarily avoided the formation of a compact oil fouling layer. When the voltage was applied, accompanied by the electrophoresis effect, redistribution of surfactant molecules on the surface of oil droplets induced by an electric field made them readily captured by the microbubbles continuously generated from the electrode, thereby rapidly migrating these bubble-adhered oil droplets far from the filtration medium.

Surface co-deposition of polypyrrole nanoparticles and tannic acid for photothermal bacterial eradication

Bacterial infections on implantable materials can cause severe complications for affected patients, posing a serious threat to human health. Therefore, the development of appropriate surface modification strategies to construct the antibacterial platforms on medical implants are urgently needed. In this work, the poly(vinyl alcohol) (PVA)-stabilized polypyrrole nanoparticles (PVA-PPy NPs) were prepared by oxidative polymerization using FeCl3 as the oxidant. Subsequent mixing of the PVA-PPy NPs solution mixture with tannic acid (TA) was facilitated by hydrogen bonding. The as-formed TA/PVA-PPy NPs can be deposited with good adhesion onto solid materials in a substrate-independent manner. The hydrophilic TA/PVA-PPy NPs-deposited titanium (Ti-TPP) surface can reduce the adhesion of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In addition, the Ti-TPP surface had photothermal property under 808 nm near-infrared (NIR) irradiation, which can kill the adhered bacteria via the hyperthermal effect. Upon exposure to NIR, the respective survival rates of S. aureus and E. coli on the Ti-TPP surfaces were only 1.66% and 2.78%, in comparison to those on the pristine Ti surfaces. Furthermore, the Ti-TPP surface could prevent the formation of early-stage biofilm under NIR irradiation. The TA/PVA-PPy NPs composites can be utilized as a contact-photoactive antibacterial coating for biomedical applications.

Morphology engineering of iridium electrodes via modifying titanium substrates with controllable pillar structures for highly efficient oxygen evolution reaction

Nowadays, Ti is the well-chosen anode substrate material for proton exchange membrane electrolyzer cells (PEMECs) and modifications of the substrate surfaces are essential for the fabrication of highly efficient electrodes. Herein, we introduce the morphology engineering of Ir/Ti electrodes with different acid treatments of hydrochloric acid (HCl) and oxalic acid (OA), and the comparative benefits of these two acid treatment methods are studied from the aspects of their impacts on the morphology, interfacial contact resistance (ICR), and oxygen evolution reaction (OER) performances of resultant electrodes. Notably, compared to the flat surface from OA treatment, Ti substrates with the pillar structure could be successfully achieved via HCl etching. The HCl and the oxalic acid (OA) treatments would reduce the interfacial contact resistance (ICR) to 15.2% and 5.5% of the pristine Ti substrate at 1.38 MPa, respectively. By iridium electrodeposition on Ti substrates, Ir/Ti electrodes with different catalyst loadings are fabricated. With similar low-loadings of about 0.05 mgIr cm−2, an Ir/Ti electrode with HCl treated substrate exhibits a lower overpotential of ∼283 mV at 10 mA cm−2 current density than 305 mV from OA treatment, due to the boosted reaction areas from HCl treatment.

Transparently Passivating Catalyst of Hydrated Manganese Phosphate for Photoelectrochemical O2 Generation

A transparently hydrated manganese phosphate (“Mn–Pi”) catalyst is coated onto a Ti-doped hematite (Ti:Fe2O3) photoanode by the photo-assisted electrochemical deposition. Under a visible light illumination of 100 mW cm–2, the photocurrent density of Ti:Fe2O3/Mn–Pi reaches 0.28 mA cm–2 at 1.2 VRHE, which is around two times higher than that obtained with the pristine Ti:Fe2O3 electrode in a neutral electrolyte, and the “onset” potential reduces by 100 mV. The passivating role of the Mn–Pi catalyst is revealed experimentally. The surface states of hematite are significantly passivated after Mn–Pi deposition, which relieves the degree of Fermi level pinning of hematite and enhances the surface band bending of hematite. Therefore, the photovoltage and the charge separation are improved. Moreover, due to the valence change of the Mn element in Mn–Pi, the charge transfer through the Mn–Pi layer is favorable, which has a low charge transfer resistance for photogenerated holes. The suitability of this transparently passivating catalyst for concentrating light is also identified. This work demonstrates that Mn–Pi can be applied for photoelectrochemical water splitting as a transparently passivating catalyst.

A micro/nano-biomimetic coating on titanium orchestrates osteo/angio-genesis and osteoimmunomodulation for advanced osseointegration

Osseointegration is a sophisticated bone and implant healing process comprising of initial hematoma formation, immediate osteoimmunomodulation, angiogenesis, and osteogenesis. To fulfill rapid and satisfying osseointegration, this study developed a biomimetic implant coating that could confer the intraosseous implants a systematical regulation of the participatory processes. Herein, we shaped dissimilar nano-scale (NS) to form highly biomimetic structures of natural extracellular matrix (ECM) of the host bone and bone healing hematoma with micro/nano-scale (MNS) titania fiber-like network on the surface of titanium (Ti) implants. In vitro experiments revealed that the MNS not only facilitated osteogenic and angiogenic differentiation of bone marrow stromal cells (BMSCs) and endothelial cells, respectively, but also suppressed M1 macrophages (MΦs), whereas, stimulated pro-healing M2 phenotype. Notably, BMSCs on MNS surfaces enabled a significant immunomodulatory effect on MΦs resulting in the downregulation of inflammation-related cell signaling pathways. The favorable osteoimmune microenvironment manipulated by MNS further facilitated osteo-/angio-genesis via the crosstalk of multi-signaling pathways. In vivo evaluation mirrored the aforementioned results, and depicted that MNS induced ameliorative osseointegration when compared with the NS as well as the pristine Ti implant. The study demonstrated the modulatory effect of the multifaceted biomimetic structure on spatiotemporal regulation of the participatory processes during osseointegration.

Surface modification of titanium implant with hBMP-2/hIGF-1 for promoting biocompatibility and osteogenesis

To prepare the human bone morphogenetic protein-2(hBMP-2)/human insulin-like growth factor-1(hIGF-1)coating titanium(Ti)and assess its performance as a dental implant material. hBMP-2 and hIGF-1 were coated to the smooth surface of a Ti plate, and its efficacy for promoting bone formation and bone integration was compared with a pristine Ti plate.The surface characteristics of the metal samples were evaluated using scanning electron microscope (SEM) and by contact angle measurement.MG63 cells were seeded on the surface of the Ti plates, and MTT assay and alizarin red staining was used to examine the cell proliferation and formation of calcified nodules, respectively.Alkaline phosphatase (ALP)secretion of the cells was examined with ELISA, and cellular expressions of osteocalcin and osteopontin were detected with Western blotting for assessing osteogenesis. SEM examination showed that the surface of Ti with hBMP-2 and hIGF-1 coating presented with a radial pattern resembling snowflakes.The contact angles of non-coated Ti, hBMP-2-coated Ti, hIGF-1-coated, and hBMP-2/-hIGF-1-coated Ti samples were 83.2°, 54°, 56° and 54°, respectively.Compared with the non-coated Ti plate, the surface-modified Ti samples showed a significantly smaller contact angle (P=0.032, 0.029, and 0.028), indicating a good hydrophilicity of the samples.MTT assay showed that MG63 cells grew well on the surface of the coated Ti plates.The hBMP-2/IGF-1 coating significantly induced cellular secretion of ALP(P=0.021, 0.014)and obviously promoted osteogenesis of MG63 cells (P < 0.05).Western blotting results showed that hBMP-2/IGF-1 coating significantly enhanced the expressions of osteocalcin and osteopontin in the seeded cells (P < 0.05). hBMP-2 and hIGF-1 coating of Ti material can promote osteogenesis of the cells seeded on its surface to improve the performance of such Ti material as dental implants.

Activating Titanium Metal with H2 Plasma for the Hydrogen Evolution Reaction.

Developing a high-performance nonprecious metal electrocatalyst for water splitting is a strong demand for the large-scale application of electrochemical H2 production. In this work, we design a facile and scalable strategy to activate titanium metal for the hydrogen evolution reaction (HER) in alkaline media through incorporating hydrogen into the α-Ti crystal lattice by H2 plasma bombardment. Benefiting from the accelerated charge transfer and enlarged electrochemical surface area after H2 plasma treatment, the H-incorporated Ti shows remarkably enhanced HER activity with a much lower overpotential at -10 mA cm-2 by 276 mV when compared to the pristine Ti. It is revealed that the retention of the incorporated H(D) atoms in the Ti crystal lattice during HER accounts for the durable feature of the catalyst. Density functional theory calculations demonstrate the effectiveness of hydrogen incorporation in tuning the adsorption energy of reaction species via charge redistribution. Our work offers a novel route to activate titanium or other metals by H incorporation through a controllable H2 plasma treatment to tune the electronic structure for water splitting reactions.

Screening the Optimal Patterned Surfaces Consisting of Cell Morphology Mimicking Micro-pillars and Nanotube Arrays for the Design of Titanium Implants

Micron/nano scale topographic modification has been a significant focus of interest in current titanium (Ti) surface design. However, the influence of micron/nano structured surface on cell or bacterium behavior on the Ti implant has rarely been systematically evaluated. Moreover, except for popular microgrooves, little work has been carried out on the reaction of cells to the bionic structure. In this study, several micro-pillars mimicking cell morphology were prepared on Ti surfaces by lithography and contact printing (ICP) method, and they were further decorated with nanotube arrays by anodization technology. These surface modifications remarkablly increased the surface roughness of pristine Ti surface from 91.17 nm ± 5.57 nm to be more than 1000 nm, and reduced their water contact angles from 68.3° ± 0.7° to be 16.9° ± 2.4°. Then, the effects of these hierarchical micron/nano scale patterns on the behaviors of MG63 osteoblasts, L929 fibroblasts, SCC epithelial cells and P. gingivalis were studied, aiming to evaluate their performance in osseointegration, gingival epithelial sealing and antibacterial ability. Through an innovative scoring strategy, our findings showed that square micro-pillars with 6 µm width and 2 µm height combined with 85 nm diameter nanotubes was suitable for implant neck design, while square micro-pillars with 3 µm width and 3.6 µm height combined with 55 nm diameter nanotubes was the best for implant body design. Our study reveals the synergistic effect of the hierarchical micron/nano scale patterns on MG63 osteoblasts, L929 fibroblasts, SCC epithelial cells and P. gingivalis functions. It provides insight into the design of biomedical implant surfaces.

Advanced synthesis of MXene-derived nanoflower-shaped TiO2@Ti3C2 heterojunction to enhance photocatalytic degradation of Rhodamine B

Advanced synthesis of nanoflower structures consisting of TiO 2 @Ti 3 C 2 nanoflowers with three-dimensional (3D) porous frameworks from two-dimensional (2D) Ti 3 C 2 MXene was done and applied for degradation of organic pollutant. The special structure of material was created by the in situ transformation, starting from Ti 3 C 2 T x MXene as provision of Ti source. The basis properties of material were characterized by SEM, TEM, XRD and XPS. The Ti 3 C 2 T x MXene showed layered structure and then this morphology was replaced by nanoflower spheres with rapid growth of TiO 2 @Ti 3 C 2 nanowhiskers. In terms of application, the TiO 2 @Ti 3 C 2 heterojunction showed an extraordinary photocatalytic efficiency toward Rhodamine B (RhB) compared to performances of pristine Ti 3 C 2 , and commercial TiO 2 . In addition, the TiO 2 @Ti 3 C 2 composite also displays the good recyclability even after 5th degradation cycles. Based on the finding, it gains a deeper insight into practical applications of 2D transition metal carbide for treatment of organic pollutants in wastewater.

Simple application of adipose-derived stem cell-derived extracellular vesicles coating enhances cytocompatibility and osteoinductivity of titanium implant.

Surface modification using bioactive molecules is frequently performed to improve the biological properties of medical metal biomaterial titanium (Ti) implants. Developmental evidence suggests that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) served as potent bioactive component. As a subset of MSC-EV, adipose-derived stem cell-derived extracellular vesicles (ADSC-EVs) could be obtained from abundant adipose tissue. Meanwhile, it possesses multiple regenerative properties and might be used to endow biological activities to medical Ti implant. Here, we present a simple ADSC-EV coating strategy based on physisorption of fibronectin. This ADSC-EV functionalized Ti implants (EV-Ti) revealed enhanced osteoblast compatibility and osteoinductive activity. Cell spreading area of EV-Ti group was 1.62- and 1.48-fold larger than that of Ti group after 6 and 12 h of cell seeding, respectively. Moreover, EV-Ti promoted alkaline phosphatase, collagen 1 and osteocalcin gene expression in osteoblast by 1.51-, 1.68- and 1.82-fold compared with pristine Ti, respectively. Thus, the MSC-EVs modification method reported here provide a clinically translatable strategy to promote the bioactivity of Ti implants.

Adsorption and electrochemical regeneration of intercalated Ti3C2Tx MXene for the removal of ciprofloxacin from wastewater

Two-dimensional Ti 3 C 2 T x MXene nanosheets intercalated with sodium ions (SI-Ti 3 C 2 T x ) was synthesized by a facile batch fabrication method and applied for Ciprofloxacin (CPX) removal in the adsorption and electrochemical regeneration process. The successful synthesis and properties of the synthesized nanosheets were evaluated with X-ray diffraction (XRD), FE-scanning electron microscopy (SEM), FE-transmission electron spectroscopy, Zeta-potential analyses, and X-ray photoelectron spectroscopy. After intercalation, the surface terminations and the spacing between the layers of SI-Ti 3 C 2 T x MXene were increased which enhanced the adsorption capacity of nanosheets in terms of fast kinetics and higher removal rates. As a result, 10 mg L −1 CPX was reduced to approximately 1 mg L −1 in just 15–20 min, which is an extraordinary kinetic behavior in CPX adsorption. Elovich kinetic model and the Redlich-Peterson isotherm model fitted the experimental data with the highest correlation coefficient. SI-Ti 3 C 2 T x could be completely regenerated through an electrochemical regeneration approach within 5 min. Even after the subsequent adsorption and regeneration cycles, the removal rate enhanced up to ~99.7%. After the electrochemical treatment, the results of XRD and SEM indicated the stability of the material. Results obtained herein suggest that this type of nanoadsorbent will be useful in practical water treatment applications. • Sodium intercalated Ti 3 C 2 T x (SI-Ti 3 C 2 T x ) MXene nanosheets were fabricated using a simple batch reaction method. • The SI-Ti 3 C 2 T x MXene provided better CPX adsorption performance than pristine Ti 3 C 2 T x MXene. • An increase in spacing between layers and higher surface terminations collectively enhanced the adsorption capacity. • The electrochemical technique along with complete regeneration improved the adsorption capacity. • SI-Ti 3 C 2 T x was found to be stable for five regeneration cycles.

Ag-modified hydrogen titanate nanowire arrays for stable lithium metal anode in a carbonate-based electrolyte

Abstract In the investigation of the next-generation battery anode, Li metal has attracted increasing attention owing to its ultrahigh specific capacity and low reduction potential. However, its low columbic efficiency, limited cycling life, and serious safety hazards have hindered the practical application of rechargeable Li metal batteries. Although several strategies have been proposed to enhance the electrochemical performance of Li metal anodes, most are centered around ether-based electrolytes, which are volatile and do not provide a sufficiently large voltage window. Therefore, we aimed to attain stable Li deposition/stripping in a commercial carbonate-based electrolyte. Herein, we have successfully synthesized hydrogen titanate (HTO) nanowire arrays decorated with homogenous Ag nanoparticles (NPs) (Ag@HTO) via simple hydrothermal and silver mirror reactions. The 3D cross-linked array structure with Ag NPs provides preferable nucleation sites for uniform Li deposition, and most importantly, when assembled with the commercial LiNi0.5Co0.2Mn0.3O2 cathode material, the Ag@HTO could maintain a capacity retention ratio of 81.2% at 1 C after 200 cycles, however the pristine Ti foil failed to do so after only 60 cycles. Our research therefore reveals a new way of designing current collectors paired with commercial high voltage cathodes that can create high energy density Li metal batteries.

Interfacial/intragranular reinforcement of titanium-matrix composites produced by a novel process involving core-shell structured powder

Powder metallurgy (P/M) route is commonly adopted to fabricate titanium-matrix composites (TMCs). However, majority of the reinforcements are distributed along the grain boundaries, but are absent within the grains, such that the desired mechanical properties are rarely obtained. We have developed a novel process of interfacial/intragranular reinforcement of TMC involving core-shell structured carbon nanotubes (CNTs)/amorphous-C coated Ti–6Al–4V composite powder. In comparison to pristine Ti–6Al–4V alloy, the addition of 0.25 wt% C led to more than 500 MPa increase in compressive yield strength. This is ascribed to the synergistic strengthening effect of interfacial-distributed CNTs/TiC nanoparticles and intragranular-distributed TiC nanoplatelets. The friction coefficient was effectively reduced by more than 30% because of the pinning effect of uniform TiC nanoplatelets that were deeply embedded inside the Ti–6Al–4V matrix.

Development of titanium metal matrix composites reinforced with coated powders

This paper evaluates the feasibility of using SiC and TiC as reinforcement particulates for titanium metal matrix composites (Ti-MMC). The SiC and TiC particles were coated with titanium using a chemical coating technology in order to achieve a homogeneous mixing when they were mixed with pristine Ti. The Ti-MMC with these specially prepared reinforcements were fabricated by a conventional press and sinter route. The effects of sintering temperature in Ti matrix were investigated with respect to phase constituents, microstructure and tribology properties. No in situ phases were observed during sintering and the reinforcement and matrix show sufficient bonding, which acts as a major parameter to enhance hardness and wear resistance compared to pure Ti. All the composite samples had a high sintered density. The hardness of the composites increased with an increase in the sintering temperature. It was also noticed that with the increase in the temperature ranging from [Formula: see text]C to [Formula: see text]C, improvement in the mechanical and tribological properties of the developed titanium matrix composites could be observed. The highest hardness value [Formula: see text] was recorded for Ti-2 wt.% Ti-coated SiC composite when sintered at [Formula: see text]C for 3 h.

Assessment of synergistic effects of LP-MOCVD TiO2 and Ti surface finish for dental implant purposes

Three differently treated titanium substrates to be used in dental implant applications and with different surficial morphology were coated with titanium dioxide (TiO 2 ) films by using Low-Pressure Metal Organic Chemical Vapor Deposition (MOCVD). No literature references were found on the performance evaluation of the TiO 2 MOCVD coatings on substrates with different pristine morphology; in this work the influence of the pristine Ti surface characteristics on TiO 2 crystalline structure, morphology, wettability as well as on ion release, electrochemical behavior, tribocorrosion performance, and nano-mechanical properties were studied and discussed. It was shown that the pristine substrate influenced both the crystalline phases' formation and crystallite size. Scanning electron microscopy analyses and roughness evaluation showed the optimal conformal coverage of all the MOCVD coatings for all substrates, with grain size depending on the substrate morphology and topography. The wettability of the TiO 2 coated Ti substrates highlighted a superhydrophilic behavior and, if stored in air, decreased as a function of the time aging. Ions release tests, nanoindentation measurements, tribocorrosion, and potentiodynamic polarization experiments suggest the enhancement of functional properties of the coated samples. Titania sandblasted/acid etched coated Ti substrates generally showed the best performance of the functional properties for their use in dental implant fabrications. • TiO 2 coated samples allow better wettability in aqueous media. • Titania surface functionalization is a good strategy to reduce ion release. • Tribocorrosion studies indicate better behavior for TiO 2 coated samples. • TiO 2 surface functionalization improves the mechanical properties of bulk titanium.

Hierarchical architecture of Ti3C2@PDA/NiCo2S4 composite electrode as high-performance supercapacitors

Abstract A novel Ti 3 C 2 @PDA/NiCo 2 S 4 composites as high performance supercapacitor electrodes were synthesized by the hydrothermal treatment process. The chemical modification and uniformly coating of Ti 3 C 2 surface by polydopamine (PDA) can prevent the structural collapse and over-oxidation of Ti 3 C 2 during the hydrothermal synthesis of NiCo 2 S 4 . Furthermore, the confined-synthesis of smaller NiCo 2 S 4 particles between the Ti 3 C 2 layers, not only prevent the restacking of Ti 3 C 2 that between the adjacent monolayers during cycling, but also afford high surface areas accessible to charge transfer and ion diffusion. Thereby, enhance the electrochemical cycling stability of the Ti 3 C 2 @PDA/NiCo 2 S 4 composite. It is significant to explore how NiCo 2 S 4 alters the microstructure, morphology as well as supercapacitors performance of Ti 3 C 2 to tune the microstructure and performance of Ti 3 C 2 by appropriate hydrothermal synthesis strategy. The experimental results exhibit a prominent improvement in the supercapacitor performance, the gravimetric capacitance of Ti 3 C 2 @PDA/NiCo 2 S 4 composites achieve as high as 495 F g -1 at 2 mV s -1 , which increase the 10 times as compared to the pristine Ti 3 C 2 . Furthermore, the cycling stability of the Ti 3 C 2 @PDA/NiCo 2 S 4 composites electrode was enhanced significantly by the hierarchical architecture, and showed exceptional capacitance retention (81.16%) even after 3000 cycles. The dramatic improvement in the supercapacitors performance of Ti 3 C 2 @PDA/NiCo 2 S 4 electrodes is attributed to impressive conductive matrix Ti 3 C 2 , the effective modification of small size Ni 2 Co 2 S 4 , and the strong interfacial interaction between Ti 3 C 2 @PDA and NiCo 2 S 4 . This study demonstrating its attractive application prospect of Ti 3 C 2 Mxenes modified with bimetallic sulfide as electrode materials for high-performance supercapacitors.

Surface Immobilization of TiO2 Nanotubes with Bone Morphogenetic Protein-2 Synergistically Enhances Initial Preosteoblast Adhesion and Osseointegration.

Although titanium (Ti) alloys have been widely used as implant materials, the bioinertness of pristine Ti impairs their bioactivity and early osseointegration. In the present work, we prepared TiO2 nanotubes (TNT) layer on the titanium (Ti) surface by anodic oxidation. The anodized surface was functionalized with human bone morphogenetic protein-2 coating to form the hBMP-2/TNT surface. The release behavior of hBMP-2 on the hBMP-2/TNT surface displayed a controlled and sustained pattern, compared to that on the hBMP-2/Ti surface, which showed a rapid release. In vitro cellular activity tests demonstrated that both TNT and hBMP-2/Ti surfaces, particularly the hBMP-2/TNT surface, enhanced adhesion, proliferation, and differentiation of osteoblast cells. Increased cell adhesion, improved cytoskeleton organization, and immunofluorescence staining of vinculin were observed on the modified surfaces. The TNT, hBMP-2/Ti, and hBMP-2/TNT surfaces, especially the hBMP-2/TNT surface, further displayed an upregulated gene expression of adhesion and osteogenic markers vinculin, collagen type 1, osteopontin, and osteocalcin, compared to the pristine Ti surface. In vivo experiments using a rat model demonstrated that the TNT and hBMP-2/Ti surfaces, in particular the hBMP-2/TNT surface, improved osseointegration and showed a superior bone bonding ability compared to Ti. Our study revealed a synergistic role played by TiO2 nanotubes nanotopography and hBMP-2 in promoting initial osteoblast adhesion, proliferation, differentiation, and osseointegration, thus suggesting a promising method for better modifying the implant surface.

Bulk titanium–graphene nanocomposites fabricated by selective laser melting

Abstract

Bioinspired polydopamine and polyphenol tannic acid functionalized titanium suppress osteoclast differentiation: a facile and efficient strategy to regulate osteoclast activity at bone-implant interface.

Osseointegration of metallic implants in porous osteoporotic bone remains a challenge. Surface modification of implants to reduce peri-implant osteoclastic bone resorption was explored in the study. Bioinspired polydopamine (pDOP) and polyphenol tannic acid (pTAN) are nature-derived universal coating systems that have emerged either as a sole coating or ad-layer for biomolecular conjugation on different biomaterials. The effects pDOP and pTAN on osteoclast development have not been reported before. In this study, osteoclast development was investigated on titanium (Ti) substrates coated with pDOP (Ti-pDOP) and pTAN (Ti-pTAN). The results showed that Ti-pDOP and Ti-pTAN coating reduced tartrate-resistant acid phosphatase activity and osteoclast cell number as compared with pristine Ti. Intriguingly, the reduction was higher on Ti-pTAN than on Ti-pDOP. Economical and biocompatible tannic acid serves as a superior coating in decreasing osteoclast activity when compared with that of pDOP coating and could be used to modulate osteoclast activity at bone-implant interfaces.

Loading icariin on titanium surfaces by phase-transited lysozyme priming and layer-by-layer self-assembly of hyaluronic acid/chitosan to improve surface osteogenesis ability.

PurposeIcariin (ICA) is one of the main active constituents of Herba Epimedii for improving osteogenesis. It is necessary to create a simple and efficient method to load ICA onto the surface of titanium (Ti) implant. The purpose of this study was to establish a local ICA delivery system via a layer-by-layer (LbL) self-assembly system on phase-transited lysozyme (PTL)-primed Ti surface.Materials and methodsA PTL nanofilm was first firmly coated on the pristine Ti. Then, the ICA-loaded hyaluronic acid/chitosan (HA/CS) multilayer was applied via the LbL system to form the HA/CS-ICA surface. This established HA/CS-ICA surface was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle measurement. The ICA release pattern of the HA/CS-ICA surface was also examined. MC3T3-E1 osteoblast culture test and a rat model were used to evaluate the effects of the HA/CS-ICA surface in vitro and in vivo.ResultsSEM, XPS and contact angle measurement demonstrated successful fabrication of the HA/CS-ICA surface. The HA/CS-ICA surfaces with different ICA concentrations revealed a controlled release profile of ICA during a 2-week monitoring span. Osteoblasts grown on the coated substrates displayed higher adhesion, viability, proliferation and ALP activity than those on the polished Ti surface. Furthermore, in vivo histological evaluation revealed much obvious bone formation in the ICA-coated group by histological staining and double fluorescent labeling at 2 weeks after implantation.ConclusionThe present study demonstrated that ICA-immobilized HA/CS multilayer on the PTL-primed Ti surface had a sustained release pattern of ICA which could promote the osteogenesis of osteoblasts in vitro and improve early osseointegration in vivo. This study provides a novel method for creating a sustained ICA delivery system to improve osteoblast response and osseointegration.