For decades, titanium implants have shown impressive advantages in bone repair. However, the preparation of implants with excellent antimicrobial properties as well as better osseointegration ability remains difficult for clinical application. In this study, black phosphorus nanosheets (BPNSs) were doped into hydroxyapatite (HA) coatings using electrophoretic deposition. The coatings' surface morphology, roughness, water contact angle, photothermal properties, and antibacterial properties were investigated. The BP/HA coating exhibited a surface roughness of 59.1 nm, providing an ideal substrate for cell attachment and growth. The water contact angle on the BP/HA coating was measured to be approximately 8.55°, indicating its hydrophilic nature. The BPNSs demonstrated efficient photothermal conversion, with a temperature increase of 42.2°C under laser irradiation. The BP/HA composite coating exhibited a significant reduction in bacterial growth, with inhibition rates of 95.6% and 96.1% against Staphylococcus aureus and Escherichia coli. In addition, the cytocompatibility of the composite coating was evaluated by cell adhesion, CCK8 and AM/PI staining; the effect of the composite coating in promoting angiogenesis was assessed by scratch assay, transwell assay, and protein blotting; and the osteoinductivity of the composite coating was evaluated by alkaline phosphatase assay, alizarin red staining, and Western blot. The results showed that the BP/HA composite coating exhibited superior performance in promoting biological functions such as cell proliferation and adhesion, antibacterial activity, osteogenic differentiation, and angiogenesis, and had potential applications in vascularized bone regeneration.
Durapatite , Titanium , Durapatite/pharmacology , Durapatite/chemistry , Titanium/pharmacology , Titanium/chemistry , Osseointegration , Osteogenesis , Coated Materials, Biocompatible/pharmacology , Coated Materials, Biocompatible/chemistry , Anti-Bacterial Agents/pharmacology , Water/pharmacology , Surface Properties
Sodium ion batteries (SIBs) attract most of the attention as alterative secondary battery systems for future large-scale energy storage and power batteries due to abundance resource and low cost. However, the lack of anode materials with high-rate performance and high cycling-stability has limited the commercial application of SIBs. In this paper, Cu7.2S4@N, S co-doped carbon (Cu7.2S4@NSC) honeycomb-like composite structure was designed and prepared by a one-step high-temperature chemical blowing process. As an anode material for SIBs, Cu7.2S4@NSC electrode exhibited an ultra-high initial Coulomb efficiency (94.9%) and an excellent electrochemical property including a high reversible capacity of 441.3 mAh g-1 after 100 cycles at 0.2 A g-1, an excellent rate performance of 380.4 mAh g-1 even at 5 A g-1, and a superior long-cycle stability with a capacity retention rate of approximately 100% after 700 cycles at 1A g-1.
Dielectric capacitors with higher working voltage and power density are favorable candidates for renewable energy systems and pulsed power applications. A polymer with high breakdown strength, low dielectric loss, great scalability, and reliability is a preferred dielectric material for dielectric capacitors. However, their low dielectric constant limits the polymer to achieve satisfying energy density. Therefore, great efforts have been made to get high-energy-density polymer dielectrics. By compositional and structural tailoring, the synergic integrations of the multiple components and optimized structural design effectively improved the energy storage properties. This review presents an overview of recent advancements in the field of high-energy-density polymer dielectrics via compositional and structural tailoring. The surface/interfacial engineering conducted on both microscale and macroscale for polymer dielectrics is the focus of this review. Challenges and the promising opportunities for the development of polymer dielectrics for capacitive energy storage applications are presented at the end of this review.
The construction of hierarchical nanostructures and the synergistic effect of bimetal compounds provide effective strategies to address the low energy density of supercapacitors. Herein, CoMo2 S4 (CMS) nanosheets anchored on homogeneous nanorods vertically distributed on nickel foam (NF) were fabricated using a two-step hydrothermal method. The hierarchical homostructure CMS materials heavily depend on the vulcanization parameter of the second step synthesis. As an electrode of supercapacitors, CoMo2 S4 exhibits a large specific capacity of 1992.85â F g-1 at 2â mA cm-2 , and specific capacity retention of 106 % through 8000 cycles when sulfurization condition was at 120 °C for 6â h (CMS/NF-120). Such excellent performances benefit from hierarchical homostructure, which can provide a large reaction surface area, fast ion/electron diffusion channels and rich active sites. Furthermore, the asymmetric pseudocapacitors device constructed with CMS/NF-120 and active carbon exhibits a maximum energy density of 39.8â Wh kg-1 , and good long-term stability (80.1 % capacitance retention after 10,000 cycles).
The increasing demand in energy consumption and the use of clean energy from sustainable energy sources have driven the research in the development of advanced materials for Li-ion and Na-ion batteries. In this work, we have developed a simple technique to synthesize a porous Sb structure through a galvanic replacement reaction between Sb3+ and Zn particles. The porous Sb structure consists of a three-dimensional-hierarchical structure with tree-like nanoscale Sb dendrites. The Sb in the nanodendrites is crystal of a rhombohedral structure. We construct Li-/Na-ion half cells and Li-/Na-ion full cells with the Sb nanodendrites as the active material in the working electrode and anode, respectively, and introduce an additive of vinylene carbonate for the Li-ion half/full cells and an additive of fluoroethylene carbonate for the Na-ion half/full cells. All the Li-/Na-ion half cells and Li-/Na-ion full cells exhibit excellent electrochemical performance and cycling stability. Such excellent performance can be attributed to the synergistic interaction between the three-dimensional-dendritic structure and electrolyte, which likely ensures fast transport of ions and electrons and the formation of a stable solid-state interphase.
There is a great need to develop sustainable and clean energy storage devices and systems of high-energy and high-capacity densities. In this work, we synthesize antimony (Sb) nanocrystal-anchored hollow carbon microspheres (Sb@HCMs) via the calcination of cultivated yeast cells and the reduction of SbCl3 in an ethylene glycol solution on the surface of hollow carbon microspheres. The Sb@HCMs possess hollow and porous structure, and the Sb is present in the form of nanocrystals. Using the Sb@HCMs as the active-electrode material, we assemble lithium (Li)-ion half cells and full cells and investigate their electrochemical performance. The Li-ion half cells possess a charge capacity of 605 mA h g-1 after 100 cycles at a current density of 100 mA g-1 and a charge capacity of 469.9 mA h g-1 at a current density up to 1600 mA g-1, which is much higher than the theoretical capacity of 372 mA h g-1 for commercial graphite electrode. The Li-ion full cells with Sb@HCMs//LiCoO2 deliver a charge capacity of 300 mA h g-1 at a current density of 0.2 A g-1 after 50 cycles, and have potential in applications of energy storage.
In this study, two viscoelastic creep expressions for the aspirated length of individual solid-like cells undergoing micropipette aspiration (MPA) were derived based on our previous studies wherein the cell size relative to the micropipette and the cell compressibility were taken into account. Next, three mechanical models of MPA, the half-space model (HSM), incompressible sphere model (ICSM), and compressible sphere model (CSM), were employed to fit the MPA data of chondrocytes. The results indicated that the elastic moduli and viscoelastic parameters of chondrocytes for the ICSM and CSM exhibited significantly higher values than those from the HSM (p < 0.001) because of the considerations of the geometric parameter (ξ) and the compressibility of the cell (ν). For the normal chondrocytes, the elastic moduli obtained from the ICSM and CSM (ν = 0.3) were 47.4 and 78.9% higher than those from the HSM. In the viscoelasticity, the parameters k1, k2, and µ for the ICSM were respectively increased by 37.8, 37.9, and 39.0% compared to those from the HSM, whereas for the CSM (ν = 0.3), the above parameters were 135, 314, and 257% higher compared to those from the HSM. And with the increase of ξ and ν, the above mechanical parameters decreased. Furthermore, the thresholds of ξ varying with ν were obtained for the given values of relative errors caused by the HSM in the elastic and viscoelastic parameters. The above findings obviously indicated that the geometric parameter of MPA and the Poisson's ratio of a cell have marked influences on the determination of cellular mechanical parameters by MPA and thus should be considered in the pursuit of more accurate investigations of the mechanical properties of cells.
Chondrocytes/cytology , Mechanical Phenomena , Microtechnology/instrumentation , Models, Biological , Biomechanical Phenomena
This study was dedicated to develop a nonenzymatic glucose sensor based on Ag&Pt hollow nanoparticles supported on TiO2 nanotubes. The Ag&Pt-TiO2/(500°C) was synthesized by a simple reduction and galvanic replacement method in an aqueous solution. The surface morphology and structure of Ag&Pt-TiO2/(500°C) could be examined by transmission electron microscopy, scanning electron microscopy and energy dispersive spectrometer. The mechanical behavior was measured by nanoindentation test and the hydropathy property was measured by contact angle test. It can be observed that Ag&Pt hollow structures with a particle size of 100nm and a wall thickness of 27nm were deposited on TiO2 nanotubes. The electrochemical properties were investigated by Electrochemical Workstation with three-electrode system. Ag&Pt(6h)-TiO2/(500°C) electrode exhibited excellent catalytic ability from cyclic voltammetry and fast electron transfer rate according to the electron transfer resistance of 330Ω from impedance spectroscopy. Differential pulse voltammetry results showed the sensitivity to glucose was 3.99µA∗cm-2∗mM-1, the linearity increased to 180mM and the detection limit was 22.6µM. The prepared nonenzyme glucose sensor with good analytical performance and simple preparation method looks promising in accurate glucose detection applications.
Metal Nanoparticles , Electrochemical Techniques , Glucose , Nanotubes , Platinum , Silver , Titanium
Fabrication of bioactive and mechanical matched bone substitutes is crucial for clinical application in bone defects repair. In this study, nano-hydroxyapatite/polyamide (nHA/PA) composite was coated on injection-moulded PA by a chemical corrosion and phase-inversion technique. The shear strength, gradient composition and pore structure of the bioactive coating were characterized. Osteoblast-like MG63 cells were cultured on pure PA and composite-coated PA samples. The cells' adhesion, spread and proliferation were determined using MTT assay and microscopy. The results confirm that the samples with the nHA/PA composite coating have better cytocompatibility and have no negative effects on cells. To investigate the in vivo biocompatibility, both pure PA and composite-coated PA cylinders were implanted in the trochlea of rabbit femurs and studied histologically, and the bonding ability with bone were determined using push-out tests. The results show that composite-coated implants exhibit better biocompatibility and the shear strength of the composite-coated implants with host bone at 12 weeks can reach 3.49±0.42 MPa, which is significantly higher than that of pure PA implants. These results indicate that composite-coated PA implants have excellent biocompatibility and bonding abilities with host bone and they have the potential to be applied in repair of bone defects.
Bone Substitutes/chemistry , Cell Adhesion/physiology , Durapatite/chemistry , Nanostructures/chemistry , Nylons/chemistry , Osteoblasts/chemistry , Animals , Materials Testing , Microscopy, Electron, Scanning , Porosity , Rabbits , Shear Strength , Spectrometry, X-Ray Emission , Surface Properties , Tetrazolium Salts , Thiazoles
A functionalized nitrogen-containing ordered mesoporous carbon (N-OMC), which shows good electrical properties, was synthesized by the carbonization of polyaniline inside a SBA-15 mesoporous silica template. Based on this, through entrapping laccase onto the N-OMC/polyvinyl alcohol (PVA) film a facilely fabricated amperometric biosensor was developed. Laccase from Trametes versicolor was assembled on a composite film of a N-OMC/PVA modified Au electrode and the electrochemical behavior was investigated. The results indicated that the N-OMC modified electrode exhibits electrical properties towards catechol. The optimum experimental conditions of a biosensor for the detection of catechol were studied in detail. Under the optimal conditions, the sensitivity of the biosensor was 0.29 A*M-1 with a detection limit of 0.31 µM and a linear detection range from 0.39 µM to 8.98 µM for catechol. The calibration curve followed the Michaelis-Menten kinetics and the apparent Michaelis-Menten [Formula: see text] was 6.28 µM. This work demonstrated that the N-OMC/PVA composite provides a suitable support for laccase immobilization and the construction of a biosensor.
A glucose biosensor was fabricated by electrodepositing chitosan (CS)-glucose oxidase(GOD) biocomposite onto the stainless steel needle electrode (SSN electrode) modified by Pt-Pb nanoparticles (Pt-Pb/SSN electrode). Firstly, Pt-Pb nanoparticles were deposited onto the SSN electrode and then CS-GOD biocomposite was co-electrodeposited onto the Pt-Pb/SSN electrode in a mixed solution containing p-benzoquinone (p-BQ), CS and GOD. The electrochemical results showed that the Pt-Pb nanoparticles can accelerate the electron transfer and improve the effective surface area of the SSN electrode. As a result, the detection range of the proposed biosensor was from 0.03 to 9 mM with a current sensitivity of 0.4485 µA/mM and a response time of 15 s. The Michaelis constant value was calculated to be 4.9837 mM. The cell test results indicated that the electrodes have a low cytotoxicity. This work provided a suitable technology for the fabrication of the needle-type glucose biosensor.
Biosensing Techniques , Chitosan/chemistry , Glucose Oxidase/chemistry , Glucose/analysis , Lead/chemistry , Metal Nanoparticles , Needles , Platinum/chemistry , Stainless Steel , Electrochemistry , Microscopy, Electron, Scanning
Recently, biodegradable magnesium alloys have been introduced in the field of cardiovascular stents to avoid the specific drawbacks of permanent metallic implants. However, the major obstacle of the clinical use of magnesium-based materials is their rapid corrosion rate. In this paper, a composite micro-arc oxidation/poly-L: -lactic acid (MAO/PLLA) coating was fabricated on the surface of the magnesium alloy WE42 to improve its corrosion resistance and the cytocompatibility of the modified materials was also investigated for safety aim. In our study, the morphology of materials was analyzed by Scanning electron microscopy. Potentiodynamic polarization was used to evaluate the corrosion behavior of the samples and corrosion weight loss was used to demonstrate their degradation rate. Furthermore, we applied cytotoxicity test in testing the cytocompatibility of the modified samples. The results showed that the PLLA coating effectively sealed the microcracks and micropores on the surface of the MAO coating by physical interlocking to interfere the corrosion ions. The corrosion rate was decreased and the cyototoxicity test showed that the MAO/PLLA composite coating WE42 had good cytocompatibility.
Alloys/chemistry , Lactic Acid/chemistry , Magnesium/chemistry , Polymers/chemistry , Biocompatible Materials , Cell Surface Extensions , Endothelial Cells/drug effects , Humans , Microscopy, Electron, Scanning , Oxidation-Reduction , Polyesters
