A multifaceted coating for hard tissue implants, with favorable osteogenesis, angiogenesis, and osteoimmunomodulation abilities, would be of great value since it could improve osseointegration and ...alleviate prosthesis loosening. However, to date there are few coatings that fully satisfy these criteria. Herein we describe a microporous TiO2 coating decorated with hydroxyapatite (HA) nanoparticles that is generated by micro-arc oxidation of pure titanium (Ti) and followed annealing. By altering the annealing temperature, it is possible to simultaneously tune the coating's physical (morphology and wettability) and chemical (composites and crystallinity) properties. A coating produced with micro-arc oxidization (MAO) with an annealing temperature of 650 °C (MAO-650) exhibits numerous favorable physicochemical properties, such as hybrid micro-nano morphology, superhydrophilicity, and highly crystalline HA nanoparticles. In vitro experiments reveal that the MAO-650 coating not only supports proliferation and differentiation of both osteoblasts and endothelial cells, but also inhibits the inflammatory response of macrophages and enables a favorable osteoimmunomodulation to facilitate osteo/angio-genesis. In vivo evaluation mirrors these results, and shows that the MAO-650 coating results in ameliorative osseointegration when compared with the pristine MAO coating. These data highlight the profound effect of surface physicochemical properties on the regulation of osteo/angio-genesis and osteoimmunomodulation in the enhancement of osseointegration.
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Nanofiber materials, with their porous nature and high specific surface area, can effectively adsorb and capture bacteria. Additionally, their antibacterial properties can be enhanced by ...incorporating substances with antibacterial effects and by surface modification with special chemical functional groups. Therefore, this study uses the electrospinning method to prepare polyurethane (PU) nanofiber antimicrobial membranes. Silver nanoparticles (AgNPs) will be incorporated into the PU nanofiber membranes through a green reduction method, followed by atmospheric plasma treatment to graft the zwitterionic material (2-methacryloyloxyethyl phosphorylcholine, MPC) with quaternary ammonium functional groups onto the surface. This process will result in the production of PMPC@PU/AgNPs nanofiber antimicrobial membranes. The results show that MPC grafted onto the surface of PU/AgNPs nanofiber membranes exhibits better antibacterial capability against Escherichia coli than the pristine PU/AgNPs nanofiber antimicrobial membranes, with an antibacterial efficiency reaching 99.68 ± 0.07 %. This is attributed to the synergistic effect provided by the combination of AgNPs within the PU nanofibers and the surface grafting of zwitterionic materials, leading to an antibacterial effectiveness close to 100 %. Therefore, the prepared PMPC@PU/AgNPs nanofiber antimicrobial membrane demonstrates the potential for applications in public health, specifically in areas such as food packaging materials, membrane filters and the biomedical field.
•Nanofiber antimicrobial membranes are prepared by using the electrospinning method.•Grafting MPC onto nanofiber membranes enhanced antibacterial efficiency.•The antibacterial effectiveness of nanofiber membranes is close to 100 %.
Finishing of structured surfaces is a challenging task in the manufacturing of functional surfaces. This is due to the aim of reducing the overlaying surface roughness while preserving the general ...surface structure. Therefore, there is the need for tailored tool concepts concerning the abrasive finishing. In this case, diamond-coated foams are used for the application of finishing surfaces, structured by high-feed milling. The quantitative evaluation by means of area-based roughness parameters and the qualitative observation of the changes in the surface profiles emphasise the capability to smoothen the surface without affecting the functional structure.
Hydrogen is considered as one of the most important clean and renewable energy sources for a sustainable energy future. However, its efficient and cost-effective purification still remains ...challenging. In this work, we report the development of novel zeolite@metal–organic framework (MOF) composites comprised of MOF-74 and zeolite-5A with core–shell structure for efficient purification of H2. The composites were synthesized hydrothermally through the addition of zeolite particles with and without carboxyl functional groups to the MOF synthesis solution. The zeolite/MOF weight ratio was varied systematically to find the optimum composition based on the adsorption performance. The formation of zeolite@MOF composites was confirmed by various characterization techniques. Single-component adsorption isotherms of CO2, CO, CH4, N2, and H2 over composites were measured at 25 °C to determine their equilibrium adsorption capacity. It was found that the zeolite-5A@MOF-74 with weight ratio of 5:95 exhibited a similar morphology to that of pristine MOF-74, but with higher surface area and total pore volume. Moreover, this composite showed 20–30% increase in CO2, CO, CH4, and N2 uptake than the bare MOF, which could be attributed to the formation of new mesopores at the MOF–zeolite interface. The estimated selectivity values for CO2/H2, CO/H2, CH4/H2, and N2/H2 were higher than those of the zeolite and/or MOF. Our results also indicated that surface modification of zeolite prior to composite formation does not enhance the adsorption capacities of the composites. Overall, the findings of this study suggest that the zeolite-5A@MOF-74 composites with core–shell structure are promising candidates for industrial H2 purification processes.
Nanoparticle-based therapies are found to be effective due to the unique mechanisms-of-action to engineered nanoparticles. These nanoparticles are programmed to be target specific and they can hold ...drugs along with imaging agents for simultaneous diagnostic and therapeutic purposes. They are making their way into the clinical realm. In this work we propose to develop Cadmium sulphide (CdS) nanoparticles with reduced toxicity that could function as a theranostic nanoparticle for bio- imaging applications. The work focuses on the toxicological investigation of surface modified cadmium sulphide nanoparticles. Uncoated and Chitosan coated CdS nanoparticles were synthesized by wet chemical method. The physico-chemical properties of the nanoparticles were characterized by X-ray diffraction, UV–Vis absorption, Fourier transform infrared, photoluminescence, X-ray photoelectron spectroscopy, dynamic light scattering, zeta potential and transmission electron microscopy. MTT assay was performed for toxicity profiling of the synthesized CdS nanoparticles in Human Jurkat cell and erythrocytes cell lines. The results showed a significant reduction in toxicity when the CdS nanoparticles surface was modified with Chitosan. Flow cytometer studies were performed to assess the incorporation of the synthesized nanoparticles into the cells. Photoluminescence studies showed that the surface modified CdS nanoparticles retained their fluorescence intensity regardless of their surface modification with Chitosan. Chitosan modified surface of the nanoparticles served as an effective barricade against the degradation of cadmium core. Surface modification with Chitosan, reduced the toxicity of cadmium sulphide nanoparticles retaining their fluorescent property in the cells. Thus by intentionally attaching bio-conjugates can be efficiently used for drug delivery to target specific cells as well as enable the imaging for cells.
•Chitosan coating preserves the integrity and stability of the CdS NPs.•Surface modification with chitosan showed a significant reduction in the toxicity of CdS NPs.•Chitosan modified surface served as an effective safeguard against the degradation of cadmium ions.•Chitosan coated CdS NPs can serve as an effective theranostics probe for bio-imaging.
Presented are the synthesis, characterizations, and reactive surface modification (RSM) of a novel nine atomic layered V4C3T
x MXene. With the advantages of the multilayered V4C3T
x MXene that can ...simultaneously support the RSM reaction and keep the inner skeleton stable, a series of amorphous Ni/Fe/V‐ternary oxide hydroxides thin layer can be successfully modified on the surface of the V4C3T
x MXene (denoted as MOOH @V4C3T
x, M = Ni, Fe, and V) without disrupting its original structure. Attributed to the in situ reconstruction of highly active oxide hydroxide layer, the nanohybrids exhibited an enhanced oxygen evolution reaction (OER) activity and excellent long‐time stability over 70 hours. In particular, a current density of 10 mA cm−2 can be reached by the nanohybrid with the optimized Ni/Fe ratio at an overpotential (η) as low as 275.2 mV, which is comparable to most of the state‐of‐the‐art OER catalysts and better than other MXene‐based derivatives. Demonstrated by the tunable physicochemical properties and excellent structural stability of these nanohybrids, we may envision the promising role of the M4X3‐based MXenes as substrates for a wide range of energy conversion and storage materials.
Presented are the novel nine atomic layered V4C3T
x MXene and its ternary metal oxide hydroxides modified derivatives (denoted as MOOH@V4C3T
x, M = Ni, Fe, and V). The nanohybrids present good OER activity and excellent long‐time stability, which demonstrates the promising future of multilayered M4X3 MXenes as substrates for the reactive synthesis of advanced energy conversion and storage materials.
Cellulose is a linear biopolymer which is composed of nanofibrils, thus having a large surface area. This low-cost, low-density, high-specific-surface-area, easily processable polymer is found in ...nature in the form of plants, bacteria and tunicates. Cellulose has outstanding characteristics including low cytotoxicity, biocompatibility, good mechanical properties, high chemical stability, and cost effectiveness which make them suitable candidates for biomedical applications. The manipulation of cellulose at nanoscale resulted in nanocellulose having exceptional physicochemical properties. Therefore, cellulose nanocomposite is a fascinating area of research which has applications in biomedical fields like wound healing, bone tissue engineering, three dimensional printing, drug carriers, medical implants etc. This review is mainly focused on the developments in the generation of cellulose nanocomposites and their potential applications in the biomedical field.
The dispersibility of silica sol particles modified by γ-methacryloxy propyl trimethoxyl silane (γ-MPS) in an ethanol–water mixed solvent was investigated. In the modification process, the ...hydrolysate of γ-MPS condensed to form oligomers, which further formed hydrogen bonds with the hydroxyl groups on the surface of the silica sol particles to cause agglomeration. Increasing the ethanol concentration inhibited the hydrolysis of γ-MPS and the formation of oligomers, thus inhibiting the agglomeration of silica sol particles. When the ethanol concentration was above 74 wt%, the γ-MPS-modified silica sol slurry was transparent and with a TEM image in a single-particle dispersed state. The dispersibility of the silica sol particles was determined by a double electric layer repulsion mechanism before modification and a steric hindrance mechanism by organic molecules grafted on the surface of the particles after modification. The grafting density of γ-MPS on the surface of silica sol particles affected the hydrophobicity of the modified particles, which can be effectively controlled.
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•High ethanol concentration facilitates high dispersibility of particles.•High ethanol concentration inhibits γ-MPS hydrolysis and particle agglomeration.•Modified particles are single-particle dispersed by steric-hindrance.•Particle hydrophobicity has a positive correlation with γ-MPS grafting density.
The preparation of a series of dispersible nano-SiO
2 by surface-modification in situ was described in this paper. It is found that some silane coupling agents can be combined with nano-SiO
2 by ...covalent bonds, which change the nanoparticle's surface properties and make nano-SiO
2 disperse well and steadily in many organic mediums. The structure of nanoparticles was characterized by transmission electron microscopy (TEM), infrared spectrum (IR), X-ray photoelectron spectra (XPS) and thermogravimetric analysis (TG). The dispersivity of these nanoparticles in organic solvents was measured by light transmittance. Considering such superior dispersion in oily solvents and very small size, we primarily investigated their tribological behaviors as additive in lubricant on wear testers. The results show that they can evidently increase anti-wear ability and reduce the friction coefficient of lubricant.
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•The MPC-decorated anti-fouling SIS based bio-patch has been prepared via Michael addition.•The MPC-decorated SIS bio-patch shows excellent foul resistance than commercial ...patches.•The MPC-decorated SIS bio-patch is capable of promoting vascularization and inflammation modulation.•The MPC-decorated SIS bio-patch achieves superior wound regeneration in diabetes via activating TGF-β and MAPK pathways.
Chronic wounds in diabetes take a lifetime risk of developing into diabetic foot ulcers (DFUs). Conventional wound dressings and commercial products fail for ideal tissue regeneration in DFUs due to the incapacity to promote vascularization and prevent bacterial infections during wound repair. In this study, the small intestinal submucosa (SIS) with enriched vascularized bioactive factors, was chemically decorated by 2-methacryloyloxy ethyl phosphorylcholine (MPC) through Michael-type addition to be endowed anti-fouling ability, in order to treat chronic wound regeneration in diabetes. In the diabetic skin injury experiment, we established the animal model by 5-mm diameter defects in the SD rats and implanted the bio-patches to the located sites. The SIS-MPC bio-patch showed superior advantages in bacterial anti-adhesion (100-fold foul resistance than commercial patches), while maintained affinity for fibroblast growth and collagen formation, as demonstrated by immunohistochemical staining from the local tissues, outperforming commercial wound dressings in tissue regeneration, which was attributed to acceleration in neovascularization and inflammation modulation through TGF-β and MAPK pathway. This novel SIS-MPC bio-patch would be a promising candidate for medical translations into diabetes and chronic wound treatments.
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