Adhesion Of Bacteria Research Articles

Biomimetic gaseous plastron for blocking fouling-associated biological colonization

Surface micro-/nanostructures and wettability play important roles in gaseous plastron stability. Inspired by the structure and function of Salvinia and lotus leaf, the microstructure-silicon dioxide-graphene-silicone rubber (MS-SiO2-GN-SR) composites with bubble trapping ability were synthesized. MS-SiO2-GN-SR can rapidly adsorb a large number of air bubbles under water to form a large gaseous plastron, which can be used as an antifouling barrier to prevent microbial invasion. MS-SiO2-GN-SR has a strong bubble adsorption function due to its superhydrophobicity and surface roughness. Under dynamic conditions, compared with GN-SR, the adhesion of Gram-negative bacteria, Gram-positive bacteria, and marine algae attachment on the surface of MS-SiO2-GN-SR decreased by 50.51%, 63.89%, and 60.8%, respectively. After 48h incubation, MS-SiO2-GN-SR still maintained the best antifouling performance. These results suggest that physical antifouling strategies based on macroscopic gaseous plastron are promising for the marine industry and maritime transport.

Development of chitosan/hydrolyzed collagen interaction product-based microparticles for the treatment of respiratory tract infections.

Respiratory tract infections (RTIs) represent a significant global health issue, particularly for vulnerable population, such as children, the elderly, or patients with immunosuppression. In this context, the aim of the present work was the development of Chitosan/Hydrolyzed Collagen-based microparticles (Mps) as a pulmonary drug delivery system (PDDS) for the treatment of RTIs. Mps were produced via spray-drying and composed of chitosan (Cs), one of the most widely used polysaccharides in PDDS, and hydrolyzed collagen (HC), another promising material for the development of PDDS that has not yet been fully explored. The formation of an interaction product between Cs and HC occurred during the spray-drying process and was confirmed by infrared spectroscopy and thermal analysis. Mps were characterized in terms of morphology, particle size, zeta potential, aerodynamic performance, swelling behavior and biodegradation profile in simulated lung fluid. Mps biocompatibility was also assessed on adenocarcinomic human alveolar basal epithelial (A549) cells. Finally, Mps were characterized in vitro for antibacterial properties and their ability to inhibit bacterial adhesion to S. aureus and P. aeruginosa. An enhanced antibacterial effect was observed for Mps with respect to the pristine materials (Cs and HC) and their physical mixture. Moreover, Mps were also able to inhibit bacteria adhesion to epithelial cells.

In Vitro Infection of Human Macrophages with Porphyromonas gingivalis W83

This study aimed to investigate the innate immune response of human macrophages to Porphyromonas gingivalis W83 using a novel in vitro infection model. The growth kinetics of P. gingivalis W83 were analyzed, revealing an exponential growth phase at 8 h (optical density = 0.70). To establish a reliable macrophage model, the differentiation of THP-1 monocytes into macrophages was optimized using low concentrations of phorbol 12-myristate 13-acetate (PMA). This approach induced enhanced adherence and morphological changes, with full differentiation achieved after 48 h of PMA treatment followed by 24 h of rest. Polarization towards the pro-inflammatory M1 phenotype was successfully induced with interferon-γ (IFN-γ) and lipopolysaccharide (LPS), as confirmed using cytokine profiling. Cytokine analysis using Luminex® technology demonstrated significant increases in interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and IL-6, indicating the effective activation of macrophages towards a pro-inflammatory phenotype. Building upon this macrophage model, this study investigated the interactions between macrophages and P. gingivalis W83 during its exponential growth phase. After a one-hour infection period, bacterial DNA quantification in supernatants and lysed macrophages revealed minimal levels of internalized or adherent bacteria, supporting the hypothesis that P. gingivalis effectively evades immune detection. These findings emphasize the utility of this model in uncovering the sophisticated immune evasion strategies employed by P. gingivalis, with significant implications for the development of targeted therapeutic interventions.

Lubricating Copolymer Brushes Achieving Excellent Antiadhesion and Antibacterial Performance through Hydration and Electrostatic Repulsion Effects.

Interventional catheters have been widely applied in diagnostics, therapeutics, and other biomedical areas. The complications caused by catheter-related bacterial infection, venous thrombosis, and vascular abrasion have become the main reasons for the failure of interventional therapy. In this study, polyacrylamide/poly(acrylic acid) lubricating copolymer brushes were constructed on the surface of catheters and efficiently resisted the adhesion of blood components and bacteria through hydration and electrostatic repulsion effects. The copolymer brushes are surface-independently constructed on various substrates through a three-step method. The brushes achieve effective lubricating, antiadhesion, and antibacterial properties. Particularly, the 2PAM/6PAA brushes exhibited the most excellent overall performance with a 94% reduction in coefficient of friction, 87.2 and 78.3% reduction in adhesion levels of bovine serum albumin and bovine blood fibrin, and 92.3, 97.1, and 93.5% reduction in adhesion levels of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The 2PAM/6PAA brushes significantly reduced the adhesion of blood components in the in vitro blood circulation test, demonstrating its practical application efficacy. Additionally, experiments and molecular dynamics simulations were used to reveal the antiadhesion mechanism of the brushes. Thus, the copolymer brushes in this work show great potential in the antithrombotic, antibacterial, and lubrication modification for medical devices contacting with blood.

High-Efficiency Electrochemiluminescence Biosensor with Antifouling and Antibacterial Functions for Sensitive and Accurate Analysis of Chloramphenicol in Seawater.

In marine environmental monitoring, due to the presence of a large number of interfering proteins and bacteria in seawater, it is of great significance to construct an efficient sensing interface with antifouling and antibacterial functions to avoid the aforementioned interferences. On this basis, the zwitterionic hydrogel based on sulfobetaine methacrylate (SBMA) and bovine serum albumin (BSA) was developed as an antifouling and antibacterial coating. The combination of hydration of zwitterions and hydrophilicity of hydrogels endows BSA@PSBMA with good antiadsorption ability, which effectively hinders the adhesion of proteins and bacteria, thereby improving the detection sensitivity of the biosensor. At the same time, the covalent grafting of SBMA and BSA solves the defect of poor stability of individual BSA in complex matrices, improving the stability and service life of the biosensor. In addition, Au@luminol was encapsulated in the zwitterionic hydrogel as an internal standard to realize a one-step integration of antifouling and ratio strategies, which simplifies the construction process of the biosensor. The developed electrochemiluminescence biosensor exhibited good sensitivity and accuracy for chloramphenicol detection, with a wide linear range of 1 pM to 100 nM and a low detection limit of 0.39 pM (S/N = 3), which is suitable for trace detection of antibiotics in seawater.

PH-sensitive polyglycerol nanogels for periodontitis treatment through antibacterial and pro-angiogenesis action.

Periodontitis is a microbe-driven inflammatory disease leading to bone resorption and tissue destruction. We propose a dual-functional nanogel complex armed with the antimicrobial drug triclosan (TCS) and the pro-angiogenesis medication deferoxamine (DFO) for combating microbial pathogens and promoting tissue regeneration. The nanogel system (NG-TCS-DFO) that we fabricated from linear polyglycerol exhibits well-defined spherical morphology and a positively charged surface for bacteria adhesion. The rapid and sustained degradation of NG-TCS-DFO in the acidic environment of an infection site induces the on-demand release of TCS and DFO. The NG-TCS-DFO shows potent bacteria elimination of the gingivitis-causing bacteria Porphyromonas gingivalis in both planktonic (99.9%) and biofilm (99%) states. Furthermore, the NG-TCS-DFO can promote vascularization and migration of human umbilical vein endothelial cells (HUVECs). Contributing to the synergistic effect of TCS and DFO, the NG-TCS-DFO demonstrates significant bone tissue regeneration and accelerated healing of periodontitis in vivo. This polyglycerol-based nanogel may therefore offer smart combined delivery of multiple therapeutics against bacteria-driven diseases.

PH‐sensitive polyglycerol nanogels for periodontitis treatment through antibacterial and pro‐angiogenesis action

Periodontitis is a microbe‐driven inflammatory disease leading to bone resorption and tissue destruction. We propose a dual‐functional nanogel complex armed with the antimicrobial drug triclosan (TCS) and the pro‐angiogenesis medication deferoxamine (DFO) for combating microbial pathogens and promoting tissue regeneration. The nanogel system (NG‐TCS‐DFO) that we fabricated from linear polyglycerol exhibits well‐defined spherical morphology and a positively charged surface for bacteria adhesion. The rapid and sustained degradation of NG‐TCS‐DFO in the acidic environment of an infection site induces the on‐demand release of TCS and DFO. The NG‐TCS‐DFO shows potent bacteria elimination of the gingivitis‐causing bacteria Porphyromonas gingivalis in both planktonic (99.9%) and biofilm (99%) states. Furthermore, the NG‐TCS‐DFO can promote vascularization and migration of human umbilical vein endothelial cells (HUVECs). Contributing to the synergistic effect of TCS and DFO, the NG‐TCS‐DFO demonstrates significant bone tissue regeneration and accelerated healing of periodontitis in vivo. This polyglycerol‐based nanogel may therefore offer smart combined delivery of multiple therapeutics against bacteria‐driven diseases.

Potential effects of prebiotic fibers on dental caries: a systematic review.

Certain dietary fibers exhibit prebiotic effects on gut microbiota, but their influence on oral health remains unclear. This study conducted a systematic review across four databases to examine the potential effects of dietary fibers on dental caries. Data selection and extraction were conducted independently and in duplicate. From 962 found titles, twenty studies were included, of which 13 were in vitro. The substances identified as prebiotics included fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), inulin, pectin, raffinose, polydextrose, sialyllactose, and short-chain fatty acids. Outcomes were assessed at biofilm (n = 14), saliva (n = 5), and tooth (n = 1) levels, with only six studiesevaluating pH changes. Fifteen studies (75%) reported potential benefits, primarily attributed to the capacity of prebiotic fibers to limit the growth or adhesion of bacteria. Only two studies (10%) reported an increase in pH. Overall, the quality of the evidence was judged as moderate. In conclusion, certain dietary fibers may help limit caries development by modulating biofilm and pH levels. However, further clinical studies are needed to confirm the protective role of dietary fibers in dental caries. © 2025 Society of Chemical Industry.

Anti-Inflammatory and Prebiotic Potential of Ethanol Extracts and Mucilage Polysaccharides from Korean Yams (Dioscorea polystachya and Dioscorea bulbifera).

Korean yams are abundant in bioactive compounds with significant health-promoting properties. This study evaluated the anti-inflammatory potential of ethanol and water extracts from Dioscorea polystachya and Dioscorea bulbifera in RAW 264.7 macrophage cells. Among the extracts, the 95% ethanol extract exhibited the most potent inhibition of reactive oxygen species (ROS) and nitric oxide (NO) production, warranting further exploration of its mechanisms of action. Further analysis revealed that the ethanol extract modulated key inflammatory signaling pathways, including MAPK and NF-κB, contributing to its anti-inflammatory activity. Additionally, mucilage polysaccharides, a key bioactive component of Korean yams, were extracted and characterized for their structural and functional properties. These polysaccharides demonstrated immune-enhancing effects by reducing ROS and NO production while increasing phagocytic activity in the RAW 264.7 cells. Their prebiotic potential was also assessed through microbial growth assays, which showed an enhanced proliferation of beneficial bacteria such as Lactobacillus and Bifidobacterium. Furthermore, the adhesion assays using Caco-2 intestinal epithelial cells revealed that these polysaccharides promoted probiotic adhesion while inhibiting the adhesion of pathogenic bacteria. These findings highlight the bioactive potential of ethanol extracts and mucilage polysaccharides from Korean yams, emphasizing their promising applications as anti-inflammatory, immune-modulating, and prebiotic agents for functional food and nutraceutical development.

Antimicrobial Resistance and Biofilm-Forming Ability in ESBL-Producing and Non-ESBL-Producing Escherichia coli and Klebsiella pneumoniae Isolated from Canine Urinary Samples from Italy.

Background: In dogs, bacterial urinary tract infections are a frequent cause of antimicrobial prescription, increasing the risk of selecting antibiotic-resistant bacteria. This study analyzed resistance patterns, the presence of extended-spectrum β-lactamases (ESBLs) and biofilm-forming capacity in E. coli and K. pneumoniae previously isolated from urine samples collected from 133 selected dogs admitted to the Veterinary Teaching Hospital of Milan, Italy, in 2021 and 2023. Methods: The E. coli and K. pneumoniae isolates were bacteriologically and genetically analyzed. Results: Overall, 53/133 (39.8%) samples had a positive microbiological culture. Thirty-four E. coli/K. pneumoniae isolates were detected, accounting for 26.5% of the examined samples. The 34 isolates included 28 E. coli and 6 K. pneumoniae. Four (11.8%) were ESBL-producing bacteria, all supported by blaCTX-M gene belonging to group 1. The K. pneumoniae isolates were significantly associated with ESBL production (p < 0.05). MIC analysis showed 11 (32.4%) multidrug-resistant isolates. Biofilm-forming capacity was observed in 23 (67.6%) isolates, regardless of bacterial species, including 20 weakly and 3 moderately adherent bacteria. All moderate biofilm producers were K. pneumoniae. Multidrug resistance (MDR) was significantly more present in strains with moderate biofilm-forming ability compared to strains with weak ability to form biofilm (p < 0.05). E. coli was confirmed as the most commonly identified urinary isolate in dogs. Conclusions: The high presence of ESBL producers and MDR in K. pneumoniae suggests mandatory in vitro susceptibility testing in the presence of this bacterium in dogs with UTI. The association of moderate biofilm production with MDR highlights the need for monitoring and surveillance of bacterial prevalence and resistance patterns of urinary isolates in dogs.

Construction of Loop Polyzwitterion Brushes on PET Sheets via the Chain-End Closure Strategy To Improve Antifouling and Hemocompatible Properties.

Steric stabilization and lubrication give loop polymer brushes enhanced antifouling properties. In the study, linear zwitterionic poly(NMASMCMS) brushes were first constructed on a poly(ethylene terephthalate) (PET) surface through surface-initiated reversible addition-fragmentation chain-transfer (SI-RAFT) polymerization. The tethered linear brushes on sheets were then thiolated with ethanolamine, followed by oxidation to form loop brushes. The chain-end closure strategy to form loop brushes is facile, with a high transformation rate. The physical and chemical structures were characterized by the water contact angle (WCA), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Loop brush grafted sheets (PET-L) exhibited better lubricity than linear brush grafted sheets (PET-B) due to the rigidity of loop brush structures. The two brushes exhibited good antifouling and hemocompatible properties on low protein adsorption, bacteria adhesion, platelet adhesion, and hemolysis. In comparison, loop brushes performed with antifouling properties superior to those of linear brushes.

Invasion of Chicken Intestinal Cells Is Higher for Enterococcus cecorum Lesion Strains Compared to Cloacal Strains in an Organoid Model.

Some strains of Enterococcus cecorum can cause spondylitis and bacterial osteomyelitis. Translocation and bacteremia are pivotal to the pathogenesis and clinical disease. Virulence typing to distinguish extra-intestinal disease of lesion from cloacal strains remains difficult. We investigated if organoids can be applied to differentiate between E. cecorum strains that are more or less virulent. Floating chicken intestinal organoids combine the complex cell system of the gut with an easily accessible apical-out orientation. The organoids were treated with four E. cecorum strains that differ in original isolation, lesion, or cloacal, and bacterial load was determined after 3 and 6 h by quantitative PCR and bacterial plating. Independent of the inoculum dose or time post inoculation, DNA levels of E. cecorum marginally differed between the strains. To determine if this was caused by adherence of bacteria to the epithelial cells, an invasion assay was developed. The organoids were inoculated with the different E. cecorum strains and after 3 or 6 h treated with an antimicrobial mixture, lysed, and quantified by bacterial plate counting. Significantly higher (p < 0.0001) numbers of bacteria isolated from lesions invaded the organoids compared to cloacal strains in a dose-dependent manner. Higher numbers of bacteria isolated from lesions invaded the organoids compared to cloacal strains in a dose-dependent manner. This study is a major step in the development of a model to study the interaction between E. cecorum and the chicken host and a model to test novel intervention strategies to prevent translocation of bacteria.

Photoelectron Therapy Preventing the Formation of Bacterial Biofilm on Titanium Implants.

The exogenous bacterial infection and formation of biofilm on the surface of titanium implants can affect the adhesion, proliferation, and differentiation of cells associated with osteogenesis, ultimately leading to surgical failure. This study focuses on two critical stages for biofilm formation: i) bacterial adhesion and aggregation, ii) growth and proliferation. The titanium with well-organized titania nanotube arrays is first modified by nitrogen dopants, then loaded with CuFeSe2 nanoparticles to form a p-n heterojunction. Such heterojunction can effectively separate the electrons and holes generated by CuFeSe2 under NIR excitation, where CuFeSe2 serves as an electron acceptor from adherent bacteria, thus disrupting the respiratory chain and eventually affecting the metabolism. Combined with the released ions in solution and photothermal effect, the formation of bacterial biofilm on the surface of titanium implants is prevented on both stages.

Hybrid Cell Membrane-Engineered Nanocarrier for Triple-Action Strategy to Address Pseudomonas aeruginosa Infection.

Bacterial infections resistant to antimicrobial treatments, particularly those caused by Pseudomonas aeruginosa (P. aeruginosa), frequently lead to elevated mortality rates. Tackling this resistance using therapeutic combinations with varied mechanisms has shown considerable promise. In this study, a bioinspired nanocarrier is successfully designed and engineered for targeted antibiotic delivery and toxin/bacteria clearance. This is achieved by encapsulating antibiotic-loaded framework nucleic acids with hybrid cell membranes acquired from neutrophils and platelets. By coating the hybrid membrane outside the shell, nanocarriers are endowed with the function of neutrophil-like chemotaxis and platelet-like bacteria adhesion to achieve the first stage of inflammation targeting. Based on the specific binding of bacteria toxin to thehybrid membrane, the release of antibiotic-loaded framework nucleic acids is triggered by toxin-mediated membrane lysis to fulfill the second stage of toxin neutralization and bacteria killing. Meanwhile, the immunomodulation potential of framework nucleic acids enables nanocarriers to accomplish the third stage of reversing the immunosuppressive microenvironment. In mouse models of acute and chronic P. aeruginosa pneumonia, the nanocarriers can reduce bacterial burden at a low dosage and decrease mortality with negligible toxicity. In sum, these findings have illustrated the remarkable capability of nanocarriers in treating recalcitrant bacterial infections.

Amphiphilic Marine Antifouling Coatings Based on Zwitterion-Modified Silicone Polymers.

Silicone coatings are widely employed in marine antifouling applications due to their low surface energy. However, in static marine environments, pure silicone coatings are ineffective in preventing the adhesion of marine biofilms, which consist of proteins, marine bacteria, and extracellular matrices, ultimately promoting the attachment of macrofouling organisms. To address the limitations in antifouling performance under static conditions, this study introduces a silicone-based antifouling coating modified with zwitterionic polymers. Sulfobetaine (SB) zwitterionic segments were grafted onto the side chains of poly(dimethylsiloxane) (PDMS) to synthesize the amphiphilic polymer P(DMS-SB), which was incorporated into the PDMS network to create an interpenetrating network-structured silicone coating. The zwitterionic segments effectively inhibited the adhesion of proteins, bacteria, and algae through hydration effects. Compared to pure PDMS coatings, the adhesion of proteins, bacteria, and algae was reduced by 88%, 98.9%, and 99.3%, respectively. Additionally, the coating demonstrated excellent fouling-release properties, achieving a 91.3% removal rate for settled algae under water flow conditions and reducing the simulated barnacle adhesion strength by 68.4%. This coating presents a promising antifouling solution for ships, offshore structures, and aquaculture facilities in static marine environments with significant potential for widespread application.

Biocompatibility of light responsive materials prepared for accommodative intraocular lenses manufacturing.

To investigate the biocompatibility and bacterial adhesion properties of light responsive materials (LRM) and analyze the feasibility and biosafety of employing LRM in the preparation of accommodative intraocular lenses (AIOLs). Employing fundamental experimental research techniques, LRM with human lens epithelial cells (hLECs) and human retinal pigment epithelium cells (ARPE-19 cells) were co-cultured. Commercially available intraocular lenses (IOLs) were used as controls to perform cell counting kit-8 (CCK-8), cell staining under varying light intensities, cell adhesion and bacterial adhesion experiments. LRM exhibited a stronger inhibitory effect on the proliferation of ARPE19 cells than commercially available IOLs when co-cultured with the undiluted extract for 96h (P<0.05). Under other culturing conditions, the effects on the proliferation of hLECs and ARPE-19 cells were not significantly different between the two materials. Under the influence of light irradiation at intensities of 200 and 300 mW/cm2, LRM demonstrated a markedly higher inhibitory effect on the survival of hLECs compared to commercially available IOLs (P<0.0001). They also showed a stronger suppressive effect on the survival rate of ARPE-19 cells, with significant differences observed at 200 mW/cm2 (P<0.001) and extremely significant differences at 300 mW/cm2 (P<0.0001). Additionally, compared to commercially available IOLs, LRM had a higher number of cells adhering to their surface (P<0.05), as well as a significantly greater number of adherent bacterium (P<0.0001). LRM, characterized by their excellent non-contact tunable deformability and low cytotoxicity to ocular tissues, show considerable potential for use in the fabrication of AIOLs. These materials demonstrate strong cell adhesion; however, during photothermal conversion processes involving shape deformation under various light intensities, the resultant temperature rise may harm surrounding cells. These factors suggest that while the material plays a positive role in reducing the incidence of posterior capsule opacification (PCO), it also poses potential risks for retinal damage. Additionally, the strong bacterial adhesion of these materials indicates an increased risk of endophthalmitis.

Combination of Ultrasonic Cavitation and Sanitizing Agents to Reduce Bacterial Biofilm on Stainless Steel

Pathogenic bacteria can contaminate in food products and line productions that causing foods spoilage and foodborne diseases. Biofilm is the important structure to support the survival and adherence of bacteria on materials from cleaning practices. Therefore, this research aimed to investigate the combination of sanitizing agents and ultrasonic cavitation for elimination of bacterial biofilm stained on stainless steels grade 316 L. Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli were proliferated by UHT milk, palm juice, and LB broth including the construction of their biofilm on stainless steel. Growth characteristics of all bacteria cultured with LB broth exhibited 9.60 log cfu/mL that greater than UHT milk, and palm juice after incubation at 37°C for 24 hours. Particularly, E.coli that cultured with every liquid culture medium has highly constructed biofilm on stainless steel, compared to other strains. The highest reducing biofilm value of P.aeruginosa, S.aureus, and E.coli after the elimination processes with sanitizing agents and ultrasonic cavitation have been discovered 89.34%, 88.46%, 81.13%, respectively.

TiO2 nanotubes incorporated into a glaze-coating ceramic: surface roughness, color, and antibiofilm activity.

This study evaluated the surface roughness, color change, and antibacterial effect of a ceramic glaze enhanced with TiO2 nanotubes (n-TiO2). n-TiO2 (0, 2, 2.5, and 5 wt%) was added to a ceramic glaze powder, applied to the surface of forty feldspathic ceramic specimens, and sintered. The surface roughness average (Ra) before glaze application (T0) and after glaze crystallization (T1) was measured using a profilometer. The colorimetric alteration was determined by CIEDE2000 (ΔE00) and CIELab (ΔEab), and the whiteness index for dentistry (ΔWID). The antibacterial effect against S. mutans and S. sanguinis was evaluated (CFU/mL). Data were analyzed by two-way repeated-measures ANOVA, followed by the Bonferroni test (α = 0.05). No differences in ΔEab and ΔE00 were observed among groups (p > 0.05), and ΔWID was only affected by 5% n-TiO2. All groups surpassed the perception thresholds of 1.8 (ΔE00) and 2.3 (ΔEab). At T0, no Ra differences were detected among groups (p > 0.05). In T1, Ra decreased (p < 005) compared to T0, but 5% n-TiO2 increased roughness compared to the control group (without n-TiO2). The incorporation of n-TiO2 into the glaze powder did not impair bacteria adhesion, and no differences in biofilm formation were found among the concentrations (p < 0.05). The ceramic covered with a glaze containing 5% n-TiO2 caused minimal interference in the color and roughness with no effect on biofilm formation.

`Evaluation of the antimicrobial corrosion properties of electropolymerized poly(aniline-co-o-toluidine) films on carbon steel surfaces

Microbiologically influenced corrosion (MIC) can lead to structural weakening and shortened service life of carbon steel, resulting in serious economic losses and safety hazards. In particular, sulfate-reducing bacteria (SRB) produce hydrogen sulfide and sulfide during their growth and metabolism, which accelerates the corrosion of carbon steel. Thin films of poly(aniline-co-o-toluidine) (PA-co-POT) were electrodeposited on the surface of carbon steel using cyclic voltammetry in an electrolyte consisting of oxalic acid, aniline and o-toluidine monomers. The mechanical properties of the polymer films were analyzed by a micro-Vickers hardness tester. The corrosion resistance of the polymer films was evaluated by an electrochemical corrosion test and immersion test of the polymer films in a solution containing SRB and 3.5% NaCl. The results showed that PA-co-POT films have superior SRB corrosion resistance than single polymer films. The corrosion rate of PA-co-POT film was 0.0171mm/year, and the protection efficiency was 83% after 14 days of immersion in solution. In addition, due to the antibacterial properties of the PA-co-POT film, the adhesion of bacteria on its surface is significantly reduced, and local corrosion is also effectively inhibited. This study demonstrates the potential of electropolymerized aniline derivative copolymer films in preventing MIC of carbon steel and provides valuable insights for the development of new corrosion protection materials.

Fabrication of multifunctional antibacterial polypropylene via layer-by-layer assembly for potential application in reusable protective suits

The spread of the global epidemic continues to pose a serious threat, and the vast consumption of disposable polypropylene (PP) nonwoven medical protective suits presents significant environmental challenges. Therefore, the development of reusable, antibacterial PP nonwovens holds significant importance. This research presents a multifunctional PP exhibiting bacteria-killing, bacteria-releasing, and anti-bacteria adhesion, fabricated through layer-by-layer assembly utilizing modified sodium carboxymethylcellulose (CMC) and chitosan quaternary ammonium (CTS-QAS). Evaluations demonstrate that the modified PP nonwoven eliminated 99.33 % of Staphylococcus aureus (S. aureus) and 99.95 % of Escherichia coli (E. coli) in 0.5 h. Remarkably, near complete eradication of both S. aureus and E. coli within was observed in 1 h, indicating rapid antibacterial ability. Simultaneously, the material effectively inhibited bacterial attachment and facilitated the release of adhered bacteria through the thermal responsiveness of PNIPAM molecular chains. Furthermore, the modified PP nonwoven demonstrated excellent storage and wash stability, biocompatibility, and rechargeability. Therefore, the modified PP nonwoven holds considerable promise for application in reusable medical protective suits.