Nanosurface Modification Research Articles

Artificial neural networks (ANNs) and response surface methodology (RSM) for optimizing wetting and anti-bacterial properties of woven fabric

This study aims to enhance woven fabric’s antibacterial properties by coating with betel leaf extract using immersion and plasma pre-treatment techniques. It explores nano surface modification and develops mathematical models for inhibition zone values using response surface methodology (RSM) and artificial neural networks (ANNs). We divided the RSM into two groups based on the inputs, model A and model H, and then used artificial neural networks to compare the models. We analyzed fabric treatments using SEM, wetting tests, FT-IR spectrometry, and disc diffusion (Kirby-Bauer) with Staphylococcus aureus to assess nano surface modification and antibacterial properties of fabric-treated with discharged plasma. We compared the optimal inhibition zone values for polyester fabrics with plasma treatment, anti-bacterial coatings, and anti-bacterial and plasma treatment. Fabrics treated with antibacterial coating, plasma treatment, or both exhibited inhibition zones of 2.30 ± 0.50 mm, 3.00 ± 0.50 mm, and 6.40 ± 0.50 mm, respectively. Using RSM model A, wetting properties were predicted with SSE, R-squared, and RMSE values of 0.2402, 0.9999, and 0.2451, respectively. Model A also forecasted inhibition zones for different fabric treatments with R-squared values of 0.899 and 0.9579, and SSE values of 0.8038 and 0.0782, respectively. Additionally, inhibition zones were modeled using RSM model H and ANNs, yielding R-squared values of 0.9128 and 0.97724, respectively. We found that the inhibition zone value using the ANNs model had a better predictive ability than RSM. The new technique can, therefore, be used to enhance the anti-bacterial properties and absorbency of 100% polyester fabrics.

Titania (TiO2) nanotube surfaces doped with zinc and strontium for improved cell compatibility.

Titanium-based orthopedic implants are gaining popularity in recent years due to their excellent biocompatibility, superior corrosion resistance and lightweight properties. However, these implants often fail to perform effectively due to poor osseointegration. Nanosurface modification approaches may help to resolve this problem. In this work, TiO2 nanotube (NT) arrays were fabricated on commercially available pure titanium (Ti) surfaces by anodization and annealing. Then, zinc (Zn) and strontium (Sr), important for cell signaling, were doped on the NT surface by hydrothermal treatment. This very simple method of Zn and Sr doping takes less time and energy compared to other complicated techniques. Different surface characterization tools such as scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), static water contact angle, X-ray diffraction (XRD) and nanoindentation techniques were used to evaluate the modified surfaces. Then, adipose derived stem cells (ADSCs) were cultured with the surfaces to evaluate cell adhesion, proliferation, and growth on the surfaces. After that, the cells were differentiated towards osteogenic lineage to evaluate alkaline phosphatase (ALP) activity, osteocalcin expression, and calcium phosphate mineralization. Results indicate that NT surfaces doped with Zn and Sr had significantly enhanced ADSC adhesion, proliferation, growth, and osteogenic differentiation compared to an unmodified surface, thus confirming the enhanced performance of these surfaces.

Barrier Graphene Oxide on a CoCr Alloy via Silane/GO Covalent Bonding and Its Electrochemical Behavior in a Simulated Synovial Fluid Electrolyte

In this work, impermeable and ultrathin surface nanomodifications for joint applications based on graphene oxide (GO) are assembled on CoCr surfaces via covalent immobilization between GO nanosheets and silane monolayers. Two silane curing temperatures, 45 °C for 24 h and 75 °C for 30 min, on CoCr surfaces and two incubation times for GO suspension, 12 h and 24 h, on silanized CoCr surfaces are prepared. Electrochemical characterization is performed using electrochemical impedance spectroscopy (EIS) in a 3 g/L hyaluronic acid solution. Results show that GO nanosheets immobilized with silane covalent bonding confer impermeability of sp2 networks on GO and strong interfacial adhesion of GO sheets anchored to silanized CoCr via organosilane chemistry, which prevents the permeation of oxidant species at the metal interface. At short GO incubation times (12 h), the Rs values decrease with the immersion time, indicating that small species, such as metal ions, are able to diffuse through the interlayer gaps of nanolayers. Longer GO incubation times (24 h) favor the formation of bonds between the GO and the silane, thus slowing downdiffusion and metal ion release into the medium. EIS data confirm the impermeability of GO nanocoatings with lengthening GO incubation time for medical application of metallic implants.

Carbon fiber surface nano-modification and enhanced mechanical properties of fiber reinforced cementitious composites

It has been widely recognized that fiber–matrix interface has great significance on the performance of fiber-reinforced cementitious composites. In this research, an effective fiber modification method is proposed and its enhanced mechanical properties are observed. Through the condensation and polymerization of the tetraethyl orthosilicate under alkaline conditions, a thin SiO2 layer was formed on carbon fiber surface, which can react with Ca(OH)2 thus form calcium silicate hydrate to condense the fiber–matrix interface. In this paper, nano-SiO2 modified carbon fibers are produced and the mechanical properties of modified carbon fiber reinforced cementitious composites are investigated. Modified material exhibited 24.7% enhancement in flexural strength and up to 25.1% enhancement in tensile strength with the fiber volume fraction of 0.5%. Better post-crack behavior and toughness properties were also estimated, which were attributed to nano-modification strengthening the ITZ through the reaction of surface nano-SiO2 with Ca(OH)2 resulting in much more amount of CSH gel and a denser microstructure of fiber–matrix interface. The microstructure of denser interface and porosity can be found through SEM and BSEM analysis. The porosity on the observation surface of interface transition zone of unmodified fiber and modified fiber was 4.03% and 2.43%, respectively. The change of chemical elements in the interface transition zone was analyzed by line scanning, and the Ca/Si of the modified carbon fiber was significantly lower than that of the unmodified carbon fiber.

Surface modification of 316L stainless steel with multifunctional locust gum/polyethylene glycol-silver nanoparticles using different coating methods

316 L stainless steel (SS316L) has attracted significant attention in both implantable and non-implantable medical devices for its biocompatibility. However, bacterial adhesion on the surface of SS316L and corrosion after contact with body fluids challenge its usability as a bioimplant. It is therefore necessary to improve the antibacterial and anticorrosion properties of SS316L. One of the most effective ways to achieve this is to deposit a protective metal nanoparticles-based coating on the surface of SS316L. In this study, organic Locust Gum/polyethylene glycol‑silver nanoparticles (Loc/PEG-Ag NPs) were synthesized with sonochemical method, and characterized to determine their morphology, crystal structure, chemical functional groups, and antioxidant capacity. The synthesized Ag NPs were coated on SS316L with drop casting and airbrush spray coating methods. The morphological characteristics, superficial properties, antibacterial activity, and corrosion resistivity of the surface modified SS316L were evaluated. A multifaceted investigation was performed to understand the surface characteristics and to improve the productivity of the Ag NPs coating on the metallic surface. The antioxidant capacities of the spherical-shaped Loc/PEG-Ag NPs with an average size of 10 to 50 nm were found to be 17.90 ± 0.50 and 20.47 ± 0.19 mmol Trolox equivalent (TE)g−1, respectively. The airbrush spray coating treatment significantly improved the surface properties of the substrate due to the formation of a thin layer (8.47 μm), affecting interactions between Ag NPs and substrates. The Ag NPs coated SS316L demonstrated high antibacterial activity against E. coli and S. aureus at a diameter of 28 mm and 19 mm, respectively. Compared with the bare substrate, the corrosion resistance of the surface modified SS316L is improved. The results illustrated the importance of surface nano-modification in attaining favorable antibacterial and anticorrosive performance. It is believed that the Loc/PEG-Ag NPs coated SS316L could be a promising multifunctional (i.e., uniform coating +biological activity +corrosion resistance) nanoplatforms in biomedical applications.

Coupled benefits of nanotopography and titania surface chemistry in fostering endothelialization and reducing in-stent restenosis in coronary stents

Recent advances in coronary stents have all been distinctively focused towards directing re-endothelialization with minimal in-stent restenosis, potentially via alterations in surface topographical cues, for augmenting the efficacy of vascular implants. This perspective was proven by our group utilizing a simple and easily scalable nanosurface modification strategy on metallic stents devoid of any drugs or polymers. In the present work, we explore the impact of surface characteristics in modulating this cell response in-vitro and in-vivo, using titania coated cobalt-chromium (CC) stents, with and without nanotopography, in comparison to commercial controls. Interestingly, titania nanotopography facilitated a preferential cell response in-vitro as against the titania coated and bare CC surfaces, which can be attributed to surface topography, hydrophilicity, and roughness. This in turn altered the cellular adhesion, proliferation and focal contact formations of endothelial and smooth muscle cells. We also demonstrate that titania nanotexturing plays a pivotal role in fostering rapid re-endothelialization with minimal neointimal hyperplasia, leading to excellent in-vivo patency of CC stents post 8 weeks implantation in rabbit iliac arteries, in comparison to bare CC, nano-less titania coated CC, and commercial drug-eluting stents (CC DES), without administering antiplatelet agents. This exciting result for the drug and polymer-free titania nanotextured stents, in the absence of platelet therapy, reveals the possibility of proposing an alternative to clinical DES for coronary stenting.

Nanosurface modification of Ti64 implant by anodic fluorine-doped alumina/titania for orthopedic application

Given that titanium (Ti)-based alloys have been paid more attention for various biomedical applications, the formation of the nanostructured coatings on Ti-based alloys may be a promising strategy for further preclinical developments. Therefore, the present study reports a new hybrid approach that integrates the engineering and scientific aspects into a single operational framework, in which a highly efficient fluorine-doped alumina/titania coating was developed on the Ti64 implant to improve its performance in long-term operation. Besides, due to the effect of surface tuning on the biomineralization of the system, the in-situ doping mechanism and its impacts on the in-vitro bioactivity of the implant were evaluated. From the microstructural observations, a homogeneous mixed oxide nanoporous structure with a pore size between 18 and 29 nm was developed following one-step mild anodization (2 h) of the magnetron sputtered aluminum (Al) thin film on Ti64 substrate in 0.5 wt% NH4F with 4 ml de-ionized water in ethylene glycol at 20 °C using the applied potential of 60 V. The Rietveld refinement technique not only confirmed the formation of these mixed oxide phases but also provided promising refined data on the structural properties of the samples. In addition, improvements in mechanical performance, wettability and in vitro bioactivity of the system were obtained by the proposed nanosurface modification.

Enhanced initial biodegradation resistance of the biomedical Mg-Cu alloy by surface nanomodification

Mg-Cu alloys are promising antibacterial implant materials. However, their clinical applications have been impeded by their high initial biodegradation rate, which can be alleviated using nanotechnology by for example surface nanomodification to obtain a gradient nanostructured surface layer. The present work (i) produced a gradient nanostructured surface layer with a ∼500 µm thickness on a Mg-0.2 Cu alloy by a surface mechanical grinding treatment (SMGT), and (ii) studied the biodegradation behavior in Hank's solution. The initial biodegradation rate of the SMGTed samples was significantly lower than that of the unSMGTed original counterparts, which was attributed to the surface nanocrystallization, and the fragmentation and re-dissolution of Mg2Cu particles in the surface of the SMGTed Mg-0.2 Cu alloy. Furthermore, the SMGTed Mg-0.2 Cu alloy had good antibacterial efficacy. This work creatively used SMGT technology to produce a high-performance Mg alloy implant material.

Nano ZNO and surface modification ZNO with graphite oxide deposition to enhance the catalytic activity

Preparation of ZnO nanoparticles and surface modification ZnO with the carbon material graphite oxide, were synthesized. The synthesized materials were characterized by PXRD, FT-IR, and UV-visible analysis. The materials show better optical and structural properties, which are beneficial in the photocatalytic degradation studies. Under light, zinc oxide and graphite oxide were used to degrade the methyl orange solution. The prepared materials by sol-gel preparation showed enhanced catalytic activity in the photocatalytic activity of methyl orange. An optimal loading content of graphite oxide was investigated. The enhanced photocatalysis was studied in detail. The study provides a promising application for the photocatalytic degradation of organic pollutants in photocatalysis. In the present work, the authors included the new novel materials of ZnO. The ZnO is modified with the surface deposits of rGO. The combined materials of semiconductor materials show a better response to light for the degradation studies. The use of such a combination is a new study and the results reflect the modification of semiconductor materials in the p-block elements such as C, N, F, P and so on for the enhanced photocatalytic applications of semiconductor mediated materials, which are widely used in photocatalysis. The PXRD analysis of ZnO and rGO shows better crystallinity in the case of ZnO, whereas after the deposition of rGO, crystallinity is lost due to the overlap of the main base material semiconductors, which explains the new catalytic and recombination effects of the materials used.

Investigation of the physical and mechanical characteristics of the applied corrosion-resistant powder coating

This article presents the results of experimental work on the development of a laser complex for micro-and nanomodification of metal surfaces using hybrid technologies. As an alloying material, a corrosion-resistant composite powder of the national brand was chosen, which is used in industry to prevent the occurrence of corrosion formations on the working surfaces of the executive parts of machines. One of the most used national grades of structural carbon steels was chosen as the substrate. The parameters of the laser radiation varied in two parameters: scanning speeds in the range of 12-15 mm/sec and radiation power in the range of 3-5 kW. As a result of the work carried out under various power modes, prototypes were obtained. On their basis, tabular data on the obtained values of microhardness, wear resistance and friction coefficients are compiled. The description of the obtained results is given and the direction of further work is indicated.

Biological effects, applications and strategies of nanomodification of dental metal surfaces

Metals and their alloys have been applied widely in the field of stomatology due to their good properties. However, as the oral environment and oral therapeutic schemes are complex, most dental metals have the problems oflow biocompatibilityand insufficient efficacy. With the development of nanotechnology, nanomodification has provided new opportunities for the surface modification of dental metals. Materials with nanoscale morphology and nanocoatings endow dental metal surfaces with nanoproperties that stimulate and guide various biological processes, providing potential solutions to clinical problems. This review characterizes current applications of nanotechnology for dental metal surface modification, with discussion of the resulting materials’ biocompatibility, interactions with cells and antibacterial activity. We also summarize the available information on the main preparation programs and key parameters of surface nanomodification, with discussion of the special advantages and difficulties associated with the nanomodification of metals employed in the oral cavity. We provide suggestions and references for improvement of the surface performance of dental metals and facilitation of their broad application.

Nano surface modification of poly(ethylene terephthalate) fabrics for enhanced comfort properties for activewear

Moisture absorption and transport properties of fabrics determine the thermo-physiological comfort of the apparel. The study aims to investigate the application of hydrophilic metal oxide nanostructures on poly(ethylene terephthalate) (PET) fabrics and their influence on the comfort properties of PET. Both, the sol-gel synthesized nano sols and commercially available nanoparticles (NPs) of SiO2 and TiO2 with different concentrations were applied on PET fabric alone or in combination with a hydrophilic resin. The composite of nanoparticles and resin exhibited radical improvement in the moisture management behavior of PET substrate, which is crucial for its industrial viability for activewear. At add-on of < 2wt%, this nano-finishing agent led to remarkable enhancement in wettability, wickability, and evaporation of moisture. Based on the surface morphology and chemical characteristics of the treated fabrics, a mechanism has been proposed to explain the role of nanoparticles in the enhancement of moisture management properties. It has been shown that in the presence of resin, the nanoparticles form a durable network on the surface of PET fibers and play a synergistic role in moisture and heat management of the finished fabric. Infrared thermography has been used to demonstrate the potential of such combination to attain enhanced comfort properties.

Nano-Modified Titanium Implant Materials: A Way Toward Improved Antibacterial Properties.

Titanium and its alloys have superb biocompatibility, low elastic modulus, and favorable corrosion resistance. These exceptional properties lead to its wide use as a medical implant material. Titanium itself does not have antibacterial properties, so bacteria can gather and adhere to its surface resulting in infection issues. The infection is among the main reasons for implant failure in orthopedic surgeries. Nano-modification, as one of the good options, has the potential to induce different degrees of antibacterial effect on the surface of implant materials. At the same time, the nano-modification procedure and the produced nanostructures should not adversely affect the osteogenic activity, and it should simultaneously lead to favorable antibacterial properties on the surface of the implant. This article scrutinizes and deals with the surface nano-modification of titanium implant materials from three aspects: nanostructures formation procedures, nanomaterials loading, and nano-morphology. In this regard, the research progress on the antibacterial properties of various surface nano-modification of titanium implant materials and the related procedures are introduced, and the new trends will be discussed in order to improve the related materials and methods.

Next-Generation Antibiotics, Bacteriophage Endolysins, and Nanomaterials for Combating Pathogens.

This review presents various strategies to fight causative agents of infectious diseases. Species-specific programmable RNA-containing antibiotics open up new possibilities for creating next-generation of personalized drugs based on microbiome editing and can serve as a new tool for selective elimination of pathogenic bacterial species while keeping intact the rest of microbiota. Another promising approach in combating bacterial infections is genome editing using the CRISPR-Cas systems. Expanding knowledge on the molecular mechanisms of innate immunity has been actively used for developing new antimicrobials. However, obvious risks of using antibiotic adjuvants aimed at activation of the host immune system include development of the autoimmune response with subsequent organ damage. To avoid these risks, it is essential to elucidate action mechanisms of the specific ligands and signal molecules used as components of the hybrid antibiotics. Bacteriophage endolysins are also considered as effective antimicrobials against antibiotic-resistant bacteria, metabolically inactive persisters, and microbial biofilms. Despite significant advances in the design of implants with antibacterial properties, the problem of postoperative infections still remains. Different nanomodifications of the implant surface have been designed to reduce bacterial contamination. Here, we review bactericidal, fungicidal, and immunomodulating properties of compounds used for the implant surface nanomodifications, such as silver, boron nitride nanomaterials, nanofibers, and nanogalvanic materials.

Biological Response to Nanosurface Modification on Metallic Biomaterials.

New biomaterials for biomedical applications have been developed over the past few years. This work summarizes the current cell lines investigations regarding nanosurface modifications to improve biocompatibility and osseointegration. Material surfaces presenting biomimetic morphology that provides nanoscale architectures have been shown to alter cell/biomaterial interactions. Topographical and biofunctional surface modifications present a positive effect between material and host response. Nanoscale surfaces on titanium have the potential to provide a successful interface for implantable biomedical devices. Future studies need to directly evaluate how the titanium nanoscale materials will perform in in vivo experiments. Biocompatibility should be determined to identify titanium nanoscale as an excellent option for implant procedures.

English

English

Synthesis and modification of graphene nanofluid surface in terms of wettability alteration of carbonate reservoir rock

ABSTRACT One of the advanced proceedings in the petroleum industry is the use of nanotechnology for better oil recovery. Therefore, in this study, Nano-Graphene (NG) was firstly synthesized by the Hummer’s method and then modified its surface by using a new type of compound called NEA, which is an abbreviation for N-(1-Naphthyl)ethylenediamine. Then, the effect of Nano-surface modification in graphene materials on the wettability alteration at a Carbonate Reservoir Rock scale under reservoir conditions was investigated. The results of these experiments show that the use of modified graphene Nanofluids reduces the contact angle. X-ray diffraction spectroscopy methods (XRD), Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscope (FESEM) and Fourier-transform infrared spectroscopy (FTIR) were used to identify the synthesized nanomaterials and to determine the microstructure of the samples. According to the results of the contact angle experiments, nanofluids with concentrations of 0.0095, 0.025, 0.075 and 0.1 wt% have been prepared in these experiments. The results of these experiments indicate that the G-NEA nanofluid has an effective feedback on the wettability alteration from oil-wet to water-wet state of carbonate reservoir rock.

Cytotoxicity, Oxidative Stress, and Autophagy Effects of Tantalum Nanoparticles on MC3T3-E1 Mouse Osteoblasts.

As a bone implant material, porous tantalum (Ta) has better corrosion resistance and more suitable elastic modulus than titanium. Surface nanomodification can accelerate the integration of Ta implants with bone tissue, which has broad application prospects in the field of dental implantology. Due to mechanical stress and load wear, nanoscale Ta fragments are inevitably exfoliated from the implant surface and brought into direct contact with osteoblasts surrounding the implant. These wear fragments may affect the biological characteristics of osteoblasts and thus the stability of implants. To date, the interaction of nanoscale Ta fragments with osteoblasts has not been clearly investigated. In the current study, we used the mouse osteoblast cell line MC3T3-E1 to explore the effects of Ta nanoparticles (Ta-NPs) on the cytotoxicity, oxidative stress and autophagy of osteoblasts. We found that a low concentration (12.5 μg/mL) of Ta-NPs can promote the proliferation of osteoblasts, while the Ta-NPs began to induce a decrease in cell viability at concentrations ≥25 μg/mL. Increased cell mortality, reactive oxygen species (ROS) production and decreased mitochondrial membrane potential (MMP) occurred in a dose-dependent manner after Ta-NP treatment. Moreover, with Ta-NP stimulation, the ratio of LC3-II/LC3-I increased, and the level of p62 protein was reduced. However, the degradation of p62 was not continuously increased when the concentration of Ta-NPs was ≥25 μg/mL. These results indicate that Ta-NPs induced osteoblast damage via oxidative stress. Autophagy activation may be a key factor in the cellular response to Ta-NP toxicity and could have an important impact on determining the survival or death of osteoblasts.

Surface nano-modification by ion beam-assisted deposition alters the expression of osteogenic genes in osteoblasts.

Biomaterials with enhanced biocompatibility are favored in implant studies to improve the outcomes of total joint replacement surgeries. This study tested the hypothesis that nano-structured surfaces for orthopedic applications, produced by the ion beam-assisted deposition method, would enhance osteointegration by altering the expression of bone-associated genes in osteoblasts. The ion beam-assisted deposition technique was employed to deposit nano-films on glass or titanium substrates. The effects of the ion beam-assisted deposition produced surfaces on the human osteosarcoma cell line SAOS-2 at the molecular level were investigated by assays of adhesion, proliferation, differentiation, and apoptosis on coated surfaces versus uncoated cobalt-chrome, as the control. Ion beam-assisted deposition nano-coatings enhanced bone-associated gene expression at initial cell adhesion, proliferation, and differentiation compared to cobalt-chrome surfaces as assessed by polymerase chain reaction techniques. Increased cell proliferation was observed using a nuclear cell proliferation-associated antigen. Moreover, enhanced cell differentiation was determined by alkaline phosphatase activity, an indicator of bone formation. In addition, programmed cell death assessed by annexin V staining and flow cytometry was lower on nano-surfaces compared to cobalt-chrome surfaces. Overall, the results indicate that nano-coated surfaces produced by the ion beam-assisted deposition technique for use on implants were superior to orthopedic grade cobalt-chrome in supporting bone cell adhesion, proliferation, and differentiation and reducing apoptosis. Thus, surface properties altered by the ion beam-assisted deposition technique should enhance bone formation and increase the biocompatibility of bone cell-associated surfaces.

Hydrothermal treatment of etched titanium: A potential surface nano-modification technique for enhanced biocompatibility

Nanoengineering the topology of titanium (Ti) implants has the potential to enhance cytocompability and biocompatibility properties as implant surfaces play a decisive role in determining clinical success. Despite developments in various surface engineering strategies, antibacterial properties of Ti still need to be enhanced. Here a facile, cost-effective hydrothermal route was used to develop nano-patterned structures on a Ti surface. Changing hydrothermal treatment parameters such as temperature, pressure, and time, resulted in various topographies, crystal phases, and hydrophobicity. Specifically, hydrothermal treatment performed at 225 °C for 5 h, presented a novel topography with nanoflower features, exhibited no mammalian cell cytotoxicity for a time period of 14 days, and increased calcium deposition from osteoblasts. Treated samples also demonstrated antibacterial properties (without resorting to the use of antibiotics) against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. In conclusion, hydrothermal oxidation on an etched Ti surface can generate surface properties that have excellent prospects for the biomedical field.