Surface Modification Approach Research Articles

Fungal and enzymatic pretreatments of bamboo lignocellulose towards high-strength biocomposites: Biological macromolecule/enzyme interaction and bonding enhancement

An energy-intensive and chemical-consuming pretreatment of bamboo is often required to develop its high-performance composites. This study is to evaluate a fungal and enzymatic pretreatment as a sustainable surface modification approach towards high-strength bamboo biocomposites based on D. sinicus. Extracellular enzyme activity analysis suggested that the lignin oxidative enzyme and pectinase secreted by the white-rot fungus T. versicolor achieved higher reaction than the hydrolytic enzymes throughout the pretreatment. Chemical structure analysis revealed that lignin and hemicellulose were partially depolymerised and/or removed during the pretreatment, leading to a relatively higher cellulose content in D. sinicus. The analysis of physical property and microstructure suggested that the surface wettability and porosity of pretreated D. sinicus were significantly improved, facilitating the spreading and penetration of adhesive resins, which subsequently contributed to the superior interfacial bonding of the biocomposites. The tensile strength of the biocomposites increased from 195.8 MPa to 245.8 MPa and the bonding strength increased from 4.9 MPa to 6.3 MPa after the pretreatment, which were 1.26 times and 1.28 times those of the untreated biocomposite respectively. The results proved that the fungal and enzymatic pretreatment is a promising, eco-friendly and efficient surface modification approach for the preparation of high-strength lignocellulosic biocomposites.

Natural and bio-engineered stem cell-derived extracellular vesicles for spinal cord injury repair: A meta-analysis with trial sequential analysis

BackgroundStem-cell derived extracellular vesicles (EVs) have shown promise in preclinical spinal cord injury (SCI) models but lack a comprehensive literature review for clinical translation guidance. MethodsThis meta-analysis with trial sequential analysis systematically search PubMed, Web of Science, Embase, and Cochrane Library databases. Prespecified inclusion criteria were studies reporting on measurable outcomes relevant to SCI repair. Risk of bias and quality of reporting were assessed. Random-effects meta-analyses and subgroup analyses comparing natural and bio-engineered EVs were performed. The study was registered with PROSPERO (CRD42024512122). FindingsThe search identified 3935 records, of which 39 studies were included, totaling 1801 animals. Administration of EVs significantly improved locomotor function as measured by Basso-Beattie-Bresnahan or Basso-Mouse-Scale scores at 1 week (natural EVs: SMD 1.50, 95 % CI 1.06–1.95; bio-engineered EVs: SMD 1.93, 95 % CI 1.34–2.52) and 3 weeks (natural EVs: SMD 2.57, 95 % CI 1.96–3.17; bio-engineered EVs: SMD 3.16, 95 % CI 2.29–4.02) post-injury. Subgroup analyses indicated surface modification approaches were most effective among bio-engineered EV strategies. EVs also promoted nerve growth (SMD 2.95, 95 % CI 2.12–3.78), enhanced neuron conductivity (MD 0.75, 95 %CI 0.59–0.90), alleviated inflammation (SMD −3.12, 95 % CI −4.15--2.10), and reduced lesion size (SMD −2.90, 95 % CI −3.87--1.93). ConclusionsBoth natural and bio-engineered EVs improve functional and pathological outcomes in animal models of SCI. The enhanced benefits observed with bio-engineered EVs, particularly those utilizing surface modification approaches, highlight the importance of continued exploration into bio-engineering techniques to optimize EVs’ therapeutic efficacy for SCI repair.Protocol RegistrationCRD42024512122.

Synergistic effects of calcium and zinc on bio-functionalized 3D Ti cancellous bone scaffold with enhanced osseointegration capacity in rabbit model

The present research aims to develop a Ca-Zn ion-incorporated surface functionalized 3D Ti cancellous bone scaffold for bone defect repair. The scaffold is designed to mimic human cancellous bone architecture through selective laser melting-based additive manufacturing. The chemical-based surface modification approach employed here created a Ca and Zn ions incorporated nano-porous surface layer with enhanced surface roughness and hydrophilicity. The modified biomimetic scaffold improved the corrosion resistance behaviour with ICORR and ECORR values of 0.174 mA and 0.0097 V respectively. It is learned that incorporating Zn as ZnO over the scaffold has antibacterial activity against Staphylococcus aureus and Escherichia coli. The cellular response of MG-63 to the modified scaffold was evaluated through in-vitro studies which focus on the cytocompatible properties. The intra-osseous biomimetic Ti-Na-Ca:Zn 3D scaffold revealed significant improvement in the osseointegration capabilities in terms of bone mineral density (BMD) and bone volume/total volume (BV/TV) in the rabbit model. The osseointegration potential at the Ti-Na-Ca:Zn interface was evidenced by histological analysis and micro-CT imaging. In addition to this, the remarkable upregulation of osteogenic genes such as OCN, COL1A1, OPN, ALP, RUNX2, and OSX evidences the dynamics of the osseointegration process at each surgical period. This Ca and Zn surface functionalised porous architecture of the 3D Ti cancellous bone scaffold with enhanced biological response and bone integration can potentially give insights into implant customisation along with improved clinical outcomes.

A novel water‐based mechanochemical approach for surface modification of graphene platelets and their epoxy nanocomposites

AbstractGraphene (nano) platelets (GPs) are cost‐effective and possess high structural integrity, but their limited surface functional groups hinder their compatibility with polymers. In this study, an eco‐friendly, water‐based mechanochemical approach was developed to modify GPs with polyacrylamide (PAM), creating PAM graphene platelets (PAM‐GPs) with a grafting ratio of approximately 15%. The platelet was measured to be a few nanometers in thickness, and the grafted PAM provides abundant functional groups, including amide groups, which enhance compatibility with polymers. A typical polymer, bisphenol‐A epoxy, was compounded with PAM‐GPs, resulting in a high degree of exfoliation and dispersion of PAM‐GPs within the matrix. The resulting epoxy/PAM‐GP composites exhibited significantly improved mechanical properties, including an 18% increase in Young's modulus and a substantial enhancement in fracture toughness, with a 71% increase at a low filler fraction of 0.5 wt%. These improvements are attributed to the effective interfacial interaction between the PAM‐GPs and the epoxy matrix, facilitated by the grafted functional groups. This study highlights the potential of PAM‐GPs as toughening fillers for epoxy composites, emphasizing their applicability in enhancing the durability and performance of structural components in industrial applications.Highlights Polyacrylamide (PAM)‐modified graphene platelets by a water‐based approach. A strong interface promoted exfoliation and dispersion of platelets. PAM‐modified platelets improved epoxy modulus and toughness. Fractographic analysis unveils toughening mechanisms.

Novel and practical fabrication of pre-seasoned Y2O3 ceramics through surface modification

In the semiconductor industry, the long “seasoning” time required after the installation of new ceramic components in etching equipment restricts the wafer production efficiency. This study proposes a novel and practical method for the fabrication of pre-seasoned ceramics through surface modification of Y2O3 ceramics. Fluorine-containing reactive vapors were produced by utilizing NH4F as the source. Further, the formation of yttrium oxyfluoride layers on the surfaces of Y2O3 ceramics was demonstrated. The modified surface comprises a single-crystalline phase near the interface with the Y2O3 substrate. The change in the composition, crystalline nature of the modified layer, and orientation relationship with the substrate were examined via transmission electron microscopy. The kinetics of the surface modification were studied for the sintered Y2O3 bulk as well as for practical coatings such as plasma-sprayed or PVD coatings. The proposed surface modification approach can be used to fabricate pre-seasoned Y2O3 coatings, which can significantly benefit the semiconductor industry.

Facile self-assembled monolayer deposition on copper foil for high-performance lithium-metal batteries

Li metal is widely acknowledged as the optimal negative electrode material for high-energy-density Li rechargeable batteries. However, challenges arise owing to the formation of Li dendrites and poor surface stability, leading to reduced cycle life and energy efficiency, thereby limiting widespread application. In this study, we introduced a novel approach of a molecular single-layer surface modification onto a Cu foil using a self-assembled monolayer with hexamethyldisilane (HMDS) to enhance the performance of Li-metal electrodes. The deposition of a single molecular layer at the Å-level was achieved by a simple combination of precursor casting and heat treatment without greatly affecting the energy and power density. Furthermore, this process was both scalable and cost-effective, making it highly suitable for large-scale battery manufacturing. The molecular deposition of HMDS effectively mitigated electrolyte decomposition and promoted uniform Li deposition by enhancing the surface stability under repeated Li plating–stripping processes. Optical microscopy revealed the homogeneous Li plating even after extended cycling; the first cycle on the modified surface depicted uniform plating without blank spots owing to the reduced gas-phase by-products from electrolyte decomposition. Thus, HMDS modification greatly improved the cycle stability of Li-metal batteries by successfully mitigating polarization due to electrolyte decomposition. Such improvement improved the Coulombic efficiencies and enhanced the energy efficiency, especially over a wide current density range of 1–5 mA cm−2. Furthermore, full cells with LiFePO4 cathodes and HMDS-modified Cu foils exhibited extended cyclability with increased energy efficiencies.

Antibacterial and mothproofing wool fabrics modified by M-Arg/PHMG and ZnO

The increasing focus on sustainable and eco-friendly materials has sparked a growing interest in wool as a natural fiber for sustainable fashion, thanks to its skin-friendly properties, warmth, breathability, renewability and biodegradability. The advancement of wool fabrics with durable antimicrobial and moth-resistant qualities could significantly enhance the utilization of wool in the production of high-quality textiles. This study investigates the synthesis of M−Arg and polyhexamethylene guanidine hydrochloride (PHMG) and their application in the surface modification of wool fibers, with an evaluation of the antimicrobial properties of the treated fabrics. Initially, plasma was used to pre-treat the wool fibers, followed by the adsorption of M−Arg and PHMG and ZnO in situ on the fibers’ surface. The antibacterial effectiveness against gram-positive (Staphylococcus aureus, S. aureus) and gram-negative (Escherichia coli, E. coli) microorganisms was assessed through antibacterial testing of the M−Arg/PHMG/ZnO-Fiber (MPN-Fiber). Results showed that the MPN-Fiber exhibited a significantly higher antimicrobial rate compared to untreated wool fiber. The prepared MPN-Fiber inhibited E. coli and S. aureus by 99.64 ± 1.04 % and 96.47 ± 2.14 %, respectively. Additionally, the MPN-fiber has good washing resistance (20 times, lose only 10 %). The experimental results clearly demonstrated that the MPN-Fiber exhibited exemplary antibacterial and moth-proof properties, confirming the success of the innovative surface modification approach.

Synthesis, characterization, and surface modification of degradable polar hydrophobic ionic polyurethane nanoparticles for the delivery of therapeutics to vascular tissue

Degradable polar hydrophobic ionic polyurethanes (D-PHI) are an emerging class of biomaterials with particular significance for blood-contacting applications due to their immunomodulatory effects and highly customizable block chemistry. In this manuscript, D-PHI polymer was formulated as a nanoparticle excipient for the first time by inverse emulsion polymerization. The nanoparticles were optimized with consideration of diameter, surface charge, size variability, and yield as a delivery vehicle for a custom vascular therapeutic peptide. A layer-by-layer (LBL) surface modification technique using poly-L-lysine was integrated within the nanoparticle design to optimize therapeutic loading efficiency. Solvent pH played a pivotal role in emulsion micelle formation, LBL polymer secondary structure, and the polymer functional group interactions critical for high therapeutic loading. The resulting nanoparticle platform met target size (200 ± 20 nm), polydispersity (<0.07), and storage stability standards, was nontoxic, and did not affect therapeutic peptide bioactivity in vitro. Surface-modified D-PHI nanoparticles can be reproducibly manufactured at low cost, generating a highly customizable excipient platform suitable for delivery of biomolecular therapeutics. These nanoparticles have potential applications in vascular drug delivery via localized infusion, drug eluting stents, and drug-coated angioplasty balloons. Statement of significanceNanoscale excipients have become critical in the delivery of many therapeutics to enhance drug stability and targeted biodistribution through careful design of nanoparticle composition, surface chemistry, and size. This manuscript describes the development of a nanoparticle excipient derived from an immunomodulatory degradable polar hydrophobic ionic polyurethane, in combination with a layer-by-layer surface modification approach utilizing poly-L-lysine, to transport a mimetic peptide targeting smooth muscle cell migration in vascular disease. The nanoparticle platform draws on the effect of pH to maximize drug loading and tailor particle properties. The low cost and easily reproducible system presents a highly customizable platform that can be adapted for therapeutic delivery across a wide range of clinical indications.

D-arginine-functionalized carbon dots with enhanced near-infrared emission and prolonged metabolism time for tumor fluorescent-guided photothermal therapy

Carbon dots (CDs) have garnered significant interest owing to their distinctive optical properties. However, their bioimaging and biomedical applications are limited by pronounced fluorescence (FL) quenching in aqueous media and low tumor accumulation efficacy associated with their ultra-small size. This study proposes a simple surface modification approach using functioning d-arginine on CDs (d-Arg@CDs) to improve their near-infrared (NIR) FL in aqueous solution and maintain their high photothermal conversion properties. Because of the low utilization rate of dextral amino acids in animals, modifying CDs with low molecular weight d-arginine did not increase particle size but extended the metabolism time in blood circulation, thereby leading to enhanced accumulation efficacy at tumor sites in the mice model. The enhanced tumor accumulation of d-Arg@CDs resulted in significantly superior tumor NIR FL imaging and photothermal therapy performance compared with pure CDs and l-arginine functionalized CDs. This dextral amino acid modification approach is expected to be an effective tool for enhancing the biomedical applications of CDs.

Electron beam induced graft polymerized anti oil-fouling biaxial polypropylene membrane with harsh environment tolerance

The intrinsic hydrophobic behavior of biaxial-oriented polypropylene microporous membrane limits its broad application area by leading serious membrane fouling. An environment-friendly, practical, and facile to large-scale prepared surface modification process is designed to enhance the membrane wettability and oil-fouling. By employing electron beam radiation, acrylic acid, and polyvinyl alcohol in the pre-irradiation-induced graft polymerization process, a micro-nano structure was developed and the surface roughness was increased from 66.5 nm to 99.3 nm. Enhancing the grafting ratio further reduces the pore size of the final modified membrane from 54 nm to 25 nm, which is significantly smaller than the size of the emulsified oil droplet. By modifying the morphological and structural characteristics of the grafted membrane, excellent oil-fouling resistance features are attained with UWOCA value 161° and separation efficiency of 99.3 %. Moreover, the theoretical explanations for hydrophilicity and oil-fouling resistance of modified membranes are also developed using DFT calculations and the Hermia model, which shows alignment with experimental data. Consequently, considerable improvements in wettability, thermal and mechanical behavior are obtained by this facial surface modification approach, which could further broaden the modified membrane's applications area in membrane separation technology while lengthening its service life.

The Effectiveness of Curcumin Nanoparticle-Coated Titanium Surfaces in Osteogenesis: A Systematic Review.

(1) Background: This systematic review critically appraises and synthesizes evidence from in vitro studies investigating the effects of curcumin nanoparticles on titanium surface modification, focusing on cell adhesion, proliferation, osteogenic differentiation, and mineralization. (2) Methods: A comprehensive electronic search was conducted in PubMed, Cochrane Central Register of Controlled Trials, and Google Scholar databases, yielding six in vitro studies that met the inclusion criteria. The search strategy and study selection process followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A qualitative methodological assessment was performed using the SciRAP (Science in Risk Assessment and Policy) method, which evaluated the reporting and methodological quality of the included studies. (3) Results: All six studies consistently demonstrated that curcumin-coated titanium surfaces inhibited osteoclastogenesis and promoted osteogenic activity, evidenced by enhanced cell adhesion, proliferation, osteogenic differentiation, and mineralization. The mean reporting quality score was 91.8 (SD = 5.7), and the mean methodological quality score was 85.8 (SD = 10.50), as assessed by the SciRAP method. Half of the studies used hydroxyapatite-coated titanium as a control, while the other half used uncoated titanium, introducing potential variability in baseline comparisons. (4) Conclusions: This systematic review provides compelling in vitro evidence supporting the osteogenic potential of curcumin nanoparticle-coated titanium surfaces. The findings suggest that this surface modification strategy may enhance titanium implants' biocompatibility and osteogenic properties, potentially improving dental and orthopedic implant outcomes. However, the review highlights significant heterogeneity in experimental designs and a concentration of studies from a single research group. Further research, particularly in vivo studies and clinical trials from diverse research teams, is essential to validate these findings and comprehensively understand the translational potential of this promising surface modification approach.

Nanostructured multilayer Cr/CrN coatings on 316L stainless steel for proton exchange membrane fuel cell bipolar plates

Nowadays, hybrid surface modification approaches offer tailored solutions for improving the corrosion resistance and electrical conductivity of the bipolar plates (BPPs) in proton exchange membrane fuel cells (PEMFCs). In the present study, a combination of plasma nitriding and physical vapor deposition (PVD) processes was used to apply a nanometric Cr/CrN multilayer coating onto 316L stainless steel (SS316L) bipolar plates. The performance of the resulting plasma nitrided, PVD-coated, and combined plasma nitriding/PVD-coated SS316L BPPs was examined by phase and morphological characterizations, surface wettability measurements, interfacial contact resistance (ICR), and electrochemical investigations. Potentiodynamic and potentiostatic polarization evaluations, electrochemical impedance spectroscopy (EIS) and Mott-Schottky asessments were conducted on the coated samples in a simulated PEMFC cathode environment at temperatures of 25 °C and 75 °C. Results indicated that the Cr/CrN multilayer coating deposited on the plasma-nitrided 316L BPP exhibited a remarkable 100-fold improvement in corrosion resistance compared to the uncoated substrate. Also, the combination of nitriding and PVD resulted in a significant reduction of the ICR from 186 mΩ cm2 for the uncoated SS316L to 10.2 mΩ cm2 for the coated sample. Multilayer coatings based on the combination of plasma nitriding and PVD treatment can identified as promise candidates for BPP applications.

Rational construction of positively charged polyamide nanofiltration membranes for precision cation separations

Nanofiltration has gained extensive attention in various energetically efficient separations towards a sustainable water–energy nexus. However, state-of-the-art polyamide nanofiltration membranes are constrained by the inherent trade-off between water permeance and solute selectivity, and a remarkable improvement in membrane permselectivity remains a big challenge. Here we conceived a density functional theory (DFT) assisted surface modification approach using triaminoguanidine hydrochloride (TGH) as the functional modifier to fabricate polyamide membranes with extremely high surface electropositivity and well-defined nanopores to overcome this challenge. Experimental data and DFT simulation results show that TGH surface modification can significantly manipulate surface charges and polarity to facilitate water permeation and enhance Donnan exclusion selectivity. Compared with the pristine benchmark membrane, the TGH-modified membrane exhibited a 4-fold increase in water permeance and a 6-fold increase in salt rejection, which successfully breaks the trade-off, excellent monovalent/divalent cation selectivity, and superior operational stability over a wide range of testing pressure, feed pH, and operation time, outperforming state-of-the-art membranes with similar chemistry. Taken together, this study demonstrates a feasible and reliable method combining DFT and experiments to rationally tailor the membrane characteristics at the molecular level, enabling the successful fabrication of effective polyamide nanofiltration membranes with precisely regulated structural and surface properties for water purification and precision ion separations.

Combining Ultrafast Laser Texturing and Laser Hardening to Enhance Surface Durability by Improving Hardness and Wear Performance

Aluminum alloy 7075 is utilized widely across marine, aerospace, and automotive sectors. However, its surface wear resistance has hindered its application in certain tribological environments. Addressing this challenge, the current study examines a hybrid laser method to increase surface wear resistance by combining two techniques: ultrafast laser texturing and laser‐based surface hardening. Ultrafast laser processing is conducted using 3 W laser power, 100 kHz pulse repetition rate, 4 mm s−1 scanning speed, and three different scan patterns. After the texturing operation, laser‐based surface hardening is then performed on these textures using a continuous wave laser. The laser heat treatment is conducted using laser powers of 400 and 500 W with three different scan speeds of 1, 2, and 3 mm s−1. Microhardness evaluations show a notable increase in hardness, with the hardest sample exhibiting a 17.8% increase compared to the pristine sample. The laser‐textured and laser heat‐treated samples exhibit a significant reduction in the average coefficient of friction and wear volumes compared to samples that were laser‐textured but not laser heat‐treated. The investigated laser processing strategy offers a promising approach for surface modification, enhancing both mechanical properties and wear resistance of aluminum alloy 7075 surfaces.

Thermal Vapor Deposition of a Hydrophobic and Gas-Permeable Membrane on Zirconium Phosphate Cation Exchanger: An Oral Sorbent for the Urea Removal of Kidney Failure.

An oral sorbent with high capacity for NH4+ is desirable in lowering the blood urea level and mitigating the dialysis burden for end-stage kidney disease (ESKD) patients. Zirconium phosphate (ZrP) is an amorphous cation ion exchanger with high NH4+ binding capacity as a sorbent material, but its selectivity to remove NH4+ is limited in the presence of other competing ions in water solution. We previously have developed a gas-permeable and hydrophobic perfluorocarbon coating on ZrP, which improves ZrP's NH4+ selectivity. However, the coating preparation procedure, a wet chemistry approach, is complicated and time-consuming, and more importantly, the large amount of usage of acetone poses a concern for the application of ZrP as an oral sorbent. In this study, we developed a solventless coating protocol that effectively coats ZrP with tetraethyl orthosilicate (TEOS) and 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FOTS) via thermal vapor deposition (TVD) in a simplified manner. X-ray photoelectron spectroscopy (XPS) and contact angle measurements verify the two coatings are successfully deposited on the ZrP surface, and the coating condition was optimized based on an in vitro static binding study. The dynamic binding study of competing ions on Na-loaded ZrP with TVD coatings yields a maximum NH4+ removal (∼3.2 mequiv/g), which can be improved to ∼4.7 mequiv/g if H-loaded ZrP under the same coating condition is used in basic stock solutions. More importantly, both materials barely remove Ca2+ and show excellent acid resistance. The significant improvement in the NH4+ binding capacity and selectivity reported here establishes a highly promising surface modification approach to optimize oral sorbents for ESKD patients.

A study on combination of alkaline treatment and PLA/f-CNTs composite coating on corrosion, biocompatibility and antibacterial activity of Mg alloy

The present study explores the effect of combined alkaline treatments (NaOH) and the incorporation of functionalized carbon nanotubes (f-CNTs) into poly(lactic acid) (PLA) composite coatings on the corrosion resistance, biocompatibility, and antibacterial efficacy of AZ31 magnesium (Mg) alloy. Various pretreatment techniques and coating layers have been found to exert considerable influence on the phase composition, morphology, thickness, wettability, as well as corrosion resistance, and biological characteristics of the Mg alloy. The formation of an Mg(OH)2 layer on alkaline-treated Mg alloy has proven to enhance hydrophilicity, corrosion resistance, and biocompatibility. Moreover, the findings highlight that incorporating f-CNTs into PLA improves the corrosion resistance, cytocompatibility, and antibacterial activity of Mg alloy in physiological solutions and the extent of these improvements is related to the quantity of f-CNTs present in the composite coating. Additionally, the outcomes have shown that the inclusion of f-CNTs promotes the formation of carbonate based precipitates during a 14-day immersion in Ringer's solution. Overall, the combination of alkaline treatments and the PLA/f-CNTs composite coating is showcased as a promising surface modification approach for orthopedic applications.

Experimental and Comparative Heat Transfer Analysis of Heat Exchanger with Surface Modification

This research aims to enhance the heat exchanger performance by a surface modification approach. The shot peening effect on the heat transfer performance of shell and tube heat exchanger (STHE) is experimentally studied with different surface modifications of stainless steel (SS) tube-like plain SS tube, grinded surface and blast with copper, sand & iron surface. The effect of shot peening on the surface morphology of the SS outer surface is analyzed by scanning electron microscope, and it was found that the iron blast surface has a coarse grain structure. The optimum flow rate for STHE was experimentally studied by base SS tube, and its values are compared with analytical results of computational fluid dynamics and heat transfer research. The underwater medium maintained the higher and lower temperatures of 80 °C and 30 °C, respectively. Based on the logarithmic mean temperature difference, number of transfer units (NTU), overall heat transfer coefficient, effectiveness and exergy efficiency of SS and its modified surface are experimentally evaluated, and iron blasted surface offered maximum heat exchanger performance like 100% for Stanton number, 89% for Nusselt number, 89% for overall heat transfer coefficient, 89% for an NTU, 57% for effectiveness, and 148% for exergy efficiency, while compared to SS surface without modification.

Effect of surface pretreatment on the polypyrrole coating of acrylonitrile butadiene styrene. Part A: Synthesis and characterization

This paper investigates the synergistic effects of a two-step surface modification approach on acrylonitrile butadiene styrene (ABS) plastics. The first step involves a mechanical grinding pretreatment followed by chemical etching in sulfuric acid and hydrogen peroxide, which increases surface roughness and enhances the wettability of the ABS surface. The second step focuses on the chemical synthesis of polypyrrole (PPy) on the pretreated ABS, demonstrating improvements in PPy surface roughness and adhesion after grinding and chemical etching. Adhesion tests reveal a significant increase from 0 % (PPy on untreated ABS) to 66 % (PPy on the grounded ABS) and ultimately to 100 % (PPy on the grounded ABS after chemical etching). This research is dedicated to a comprehensive exploration of the fundamental mechanisms, substantiated by a rigorous analysis involving X-ray photoelectron spectroscopy (XPS) examination, scanning electron microscopy (SEM) and contact angle measurements. Furthermore, the electric conductivity of PPy coatings is enhanced through electrochemical doping of PPy using dodecyl sulfate anions (DS/PPy/ABS) and the incorporation of silver particles (Ag/PPy/ABS). Raman spectroscopy demonstrates the Surface-Enhanced Raman Scattering (SERS) effect of silver particles on PPy coatings, showcasing their interaction. X-ray diffraction (XRD) confirms the enhanced crystallinity of DS/PPy/ABS, aligning with increased conductivity after electrochemical doping with DS anions.

Effect of Co-Sputtered Copper and Titanium Oxide Coatings on Bacterial Resistance and Cytocompatibility of Osteoblast Cells.

One of the primary risk factors for implant failure is thought to be implant-related infections during the early healing phase. Developing coatings with cell stimulatory behaviour and bacterial adhesion control is still difficult for bone implants. This study proposes an approach for one-step deposition of biocompatible and antimicrobial Cu-doped TiO2 coatings via glow-discharge sputtering of a mosaic target. During the deposition, the bias of the Ti6Al4V substrates was changed. Structure examination, phase analysis, and surface morphology were carried out using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The hardness values and hydrophilic and corrosion performance were also evaluated together with cytocompatible and antibacterial examinations against E. coli and S. aureus. The results show great chemical and phase control of the bias identifying rutile, anatase, CuO, or ternary oxide phases. It was found that by increasing the substrate bias from 0 to -50 V the Cu content increased from 15.3 up to 20.7 at% while at a high bias of -100 V, the copper content reduced to 3 at%. Simultaneously, apart from the Cu2+ state, Cu1+ is also found in the biased samples. Compared with the bare alloy, the hardness, the water contact angle and corrosion resistance of the biased coatings increased. According to an assessment of in vitro cytocompatibility, all coatings were found to be nontoxic to MG-63 osteoblast cells over the time studied. Copper release and cell-surface interactions generated an antibacterial effect against E. coli and S. aureus strains. The -50 V biased coating combined the most successful results in inhibiting bacterial growth and eliciting the proper responses from osteoblastic cells because of its phase composition, electrochemical stability, hydrophilicity, improved substrate adhesion, and surface roughness. Using this novel surface modification approach, we achieved multifunctionality through controlled copper content and oxide phase composition in the sputtered films.

Biotin-modified mesoporous silica nanoparticles as a delivery system for quercetin and gallic acid for bacterial biofilm eradication

The effective management of biofilm-associated infections remains a pressing concern in clinical practice, necessitating the development of efficient eradication strategies. This study introduces biotin-modified mesoporous silica nanoparticles (MSN-Biotin) designed to facilitate the delivery of phytochemical agents, including gallic acid and quercetin, for biofilm disruption. We elucidate the synthesis, characterization, and biofilm penetration ability of MSN-Biotin towards gram-negative E. coli biofilm and gram-positive S. mutans biofilms, emphasizing their potential in anti-biofilm drug delivery. Importantly, in vitro experiments demonstrate that MSN-Biotin loaded with phytochemicals achieved significantly better penetration into E. coli and S. mutans biofilms than traditional mesoporous silica nanoparticles and better biofilm eradication ability than free phytochemical molecules. These findings underscore the promise of MSN-Biotin as a potential efficient platform for delivering antimicrobial agents. This study introduces a novel surface modification approach for the development of antibiofilm nanoparticle systems and establishes their significant potential in biofilm infection management.