Yue Dong, Lu Wang, Zifeng Zhang et al.

Science Advances • 2022

Occlusion of the T-tube (tympanostomy tube) is a common postoperative sequela related to bacterial biofilms. Confronting biofilm-related infections of T-tubes, maneuverable and effective treatments are still challenging presently. Here, we propose an endoscopy-assisted treatment procedure based on the wobbling Fe 2 O 3 helical micromachine (HMM) with peroxidase-mimicking activity. Different from the ideal corkscrew motion, the Fe 2 O 3 HMM applies a wobbling motion in the tube, inducing stronger mechanical force and fluid convections, which not only damages the biofilm occlusion into debris quickly but also enhances the catalytic generation and diffusion of reactive oxygen species (ROS) for killing bacteria cells. Moreover, the treatment procedure, which integrated the delivery, actuation, and retrieval of Fe 2 O 3 HMM, was validated in the T-tube implanted in a human cadaver ex vivo. It enables the visual operation with ease and is gentle to the tympanic membrane and ossicles, which is promising in the clinical application.

Jie Ye, Chao Wang, Chao Gao et al.

Nature Communications • 2022

Integration of methanogens with semiconductors is an effective approach to sustainable solar-driven methanogenesis. However, the H 2 production rate by semiconductors largely exceeds that of methanogen metabolism, resulting in abundant H 2 as side product. Here, we report that binary metallic active sites (namely, NiCu alloys) are incorporated into the interface between CdS semiconductors and Methanosarcina barkeri. The self-assembled Methanosarcina barkeri-NiCu@CdS exhibits nearly 100% CH 4 selectivity with a quantum yield of 12.41 ± 0.16% under light illumination, which not only exceeds the reported biotic-abiotic hybrid systems but also is superior to most photocatalytic systems. Further investigation reveal that the Ni-Cu-Cu hollow sites in NiCu alloys can directly supply hydrogen atoms and electrons through photocatalysis to the Methanosarcina barkeri for methanogenesis via both extracellular and intracellular hydrogen cycles, effectively turning down the H 2 production. This work provides important insights into the biotic-abiotic hybrid interface, and offers an avenue for engineering the methanogenesis process.

Xinlu Wang, Pengcheng Xu, Zexin Yao et al.

Frontiers in Bioengineering and Biotechnology • 2019

Wound immersion in seawater with high salt, high sodium, and a high abundance of pathogenic bacteria, especially gram-negative bacteria, can cause serious infections and difficulties in wound repair. The present study aimed to prepare a composite hydrogel composed of hyaluronic acid (HA) and quaternized chitosan (QCS) that may promote wound healing of seawater-immersed wounds and prevent bacterial infection. Based on dynamic Schiff base linkage, hydrogel was prepared by mixing oxidized hyaluronic acid (OHA) and hyaluronic acid-hydrazide (HA-ADH) under physiological conditions. With the addition of quaternized chitosan, oxidized hyaluronic acid/hyaluronic acid-hydrazide/quaternized chitosan (OHA/HA-ADH/O-HACC and OHA/HA-ADH/N-HACC) composite hydrogels with good swelling properties and mechanical properties, appropriate water vapor transmission rates (WVTR), and excellent stability were prepared. The biocompatibility of the hydrogels was demonstrated by in vitro fibroblast L929 cell culture study. The results of in vitro and in vivo studies revealed that the prepared antibacterial hydrogels could largely inhibit bacterial growth. The in vivo study further demonstrated that the antibacterial hydrogels exhibited high repair efficiencies in a seawater-immersed wound defect model. In addition, the antibacterial hydrogels decreased pro-inflammatory factors (TNF-α, IL-1β, and IL-6) but enhanced anti-inflammatory factors (TGF-β1) in wound. This work indicates that the prepared antibacterial composite hydrogels have great potential in chronic wound healing applications, such as severe wound cure and treatment of open trauma infections.

Xingyi Wan, Yunchao Zhao, Zhou Li et al.

Exploration • 2022

Electrospinning (e-spin) technique has emerged as a versatile and feasible pathway for constructing diverse polymeric fabric structures, which show potential applications in many biological and biomedical fields. Owing to the advantages of adjustable mechanics, designable structures, versatile surface multi-functionalization, and biomimetic capability to natural tissue, remarkable progress has been made in flexible bioelectronics and tissue engineering for the sensing and therapeutic purposes. In this perspective, we review recent works on design of the hierarchically structured e-spin fibers, as well as, the fabrication strategies from one-dimensional individual fiber (1D) to three-dimensional (3D) fiber arrangements adaptive to specific applications. Then, we focus on the most cutting-edge progress of their applications in flexible bioelectronics and tissue engineering. Finally, we propose future challenges and perspectives for promoting electrospun fiber-based products toward industrialized, intelligent, multifunctional, and safe applications.

Annette R. Rowe, Shuai Xu, Emily Gardel et al.

mBio • 2019

The Methanosarcinales , a lineage of cytochrome-containing methanogens, have recently been proposed to participate in direct extracellular electron transfer interactions within syntrophic communities. To shed light on this phenomenon, we applied electrochemical techniques to measure electron uptake from cathodes by Methanosarcina barkeri , which is an important model organism that is genetically tractable and utilizes a wide range of substrates for methanogenesis. Here, we confirm the ability of M. barkeri to perform electron uptake from cathodes and show that this cathodic current is linked to quantitative increases in methane production. The underlying mechanisms we identified include, but are not limited to, a recently proposed association between cathodes and methanogen-derived extracellular enzymes (e.g., hydrogenases) that can facilitate current generation through the formation of reduced and diffusible methanogenic substrates (e.g., hydrogen). However, after minimizing the contributions of such extracellular enzymes and using a mutant lacking hydrogenases, we observe a lower-potential hydrogen-independent pathway that facilitates cathodic activity coupled to methane production in M. barkeri Our electrochemical measurements of wild-type and mutant strains point to a novel and hydrogenase-free mode of electron uptake with a potential near -484 mV versus standard hydrogen electrode (SHE) (over 100 mV more reduced than the observed hydrogenase midpoint potential under these conditions). These results suggest that M. barkeri can perform multiple modes (hydrogenase-mediated and free extracellular enzyme-independent modes) of electrode interactions on cathodes, including a mechanism pointing to a direct interaction, which has significant applied and ecological implications. IMPORTANCE Methanogenic archaea are of fundamental applied and environmental relevance. This is largely due to their activities in a wide range of anaerobic environments, generating gaseous reduced carbon that can be utilized as a fuel source. While the bioenergetics of a wide variety of methanogens have been well studied with respect to soluble substrates, a mechanistic understanding of their interaction with solid-phase redox-active compounds is limited. This work provides insight into solid-phase redox interactions in Methanosarcina spp. using electrochemical methods. We highlight a previously undescribed mode of electron uptake from cathodes that is potentially informative of direct interspecies electron transfer interactions in the Methanosarcinales .

Fang Guan, Xiaofan Zhai, Jizhou Duan et al.

PLoS ONE • 2016

Certain species of sulfate-reducing bacteria (SRB) use cathodes as electron donors for metabolism, and this electron transfer process may influence the proper protection potential choice for structures. The interaction between SRB and polarized electrodes had been the focus of numerous investigations. In this paper, the impact of cathodic protection (CP) on Desulfovibrio caledoniens metabolic activity and its influence on highs trength steel EQ70 were studied by bacterial analyses and electrochemical measurements. The results showed that EQ70 under -0.85 VSCE CP had a higher corrosion rate than that without CP, while EQ70 with -1.05 VSCE had a lower corrosion rate. The enhanced SRB metabolic activity at -0.85 VSCE was most probably caused by the direct electron transfer from the electrode polarized at -0.85 VSCE. This direct electron transfer pathway was unavailable in -1.05 VSCE. In addition, the application of cathodic protection led to the transformation of sulfide rusts into carbonates rusts. These observations have been employed to provide updated recommendations for the optimum CP potential for steel structures in the presence of SRB.

Vidyasagar, Ritu Raj Patel, Sudhir Singh et al.

Materials Advances • 2023

Schematic representation of the green synthesized silver nanoparticles, its types, mode of delivery and several biological applications.

Saba Sehar, Farooq Sher, Shengfu Zhang et al.

Journal of Molecular Liquids • 2020

Carolina Angulo-Pineda, Kasama Srirussamee, Patricia Palma Fluxá et al.

Nanomaterials • 2020

Applying electrical stimulation (ES) could affect different cellular mechanisms, thereby producing a bactericidal effect and an increase in human cell viability. Despite its relevance, this bioelectric effect has been barely reported in percolated conductive biopolymers. In this context, electroactive polycaprolactone (PCL) scaffolds with conductive Thermally Reduced Graphene Oxide (TrGO) nanoparticles were obtained by a 3D printing method. Under direct current (DC) along the percolated scaffolds, a strong antibacterial effect was observed, which completely eradicated S. aureus on the surface of scaffolds. Notably, the same ES regime also produced a four-fold increase in the viability of human mesenchymal stem cells attached to the 3D conductive PCL/TrGO scaffold compared with the pure PCL scaffold. These results have widened the design of novel electroactive composite polymers that could both eliminate the bacteria adhered to the scaffold and increase human cell viability, which have great potential in tissue engineering applications.

Aziz Maleki, Matineh Ghomi, Nasser Nikfarjam et al.

Advanced Functional Materials • 2022

Abstract MXenes (viz., transition metal carbides, carbonitrides, and nitrides) have emerged as a new subclass of 2D materials. Due to their outstanding physicochemical and biological properties, MXenes have gained much attention in the biomedical field in recent years, including drug delivery systems, regenerative medicine, and biosensing. Additionally, the incorporation of MXenes into hydrogels has garnered significant interest in biomedical engineering as an electroactive and mechanical nanoreinforcer capable of converting nonconductive scaffolds into excellent conductors of electricity with an impressive effect on mechanical properties for the engineering of electroactive organs and tissues such as cardiac, skeletal muscle, and nerve. However, many questions and problems remain unresolved that need to be answered to usher these 2D materials toward their true destiny. Thus, this review paper aims to provide an overview of the design and applications of MXene‐integrated composites for biomedical applications, including cardiac tissue engineering, wound healing, infection therapy, cancer therapy, and biosensors. Moreover, the current challenges and limitations of utilizing MXenes in vivo are highlighted and discussed, followed by its prospects as a guideline toward possible various futuristic biomedical applications. This review article will inspire researchers, who search for properties, opportunities, and challenges of using this 2D nanomaterial in biomedical applications.

Lei Nie, Qianqian Wei, Meng Sun et al.

International Journal of Biological Macromolecules • 2023

Andréia Borges Scriboni, Verônica Muniz Couto, Lígia Nunes de Morais Ribeiro et al.

Frontiers in Pharmacology • 2019

Objective: The aim of the present study was to encapsulate vancomycin in different liposomal formulations and compare the in vitro antimicrobial activity against Staphylococcus aureus biofilms. Methods: Large unilamellar vesicles of conventional (LUV VAN), fusogenic (LUV fuso VAN), and cationic (LUV cat VAN) liposomes encapsulating VAN were characterized in terms of size, polydispersity index, zeta potential, morphology, encapsulation efficiency (%EE) and in vitro release kinetics. The formulations were tested for their Minimum Inhibitory Concentration (MIC) and inhibitory activity on biofilm formation and viability, using methicillin-susceptible S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 strains. Key Findings: LUV VAN showed better %EE (32.5%) and sustained release than LUV fuso VAN, LUV cat VAN, and free VAN. The formulations were stable over 180 days at 4°C, except for LUV VAN, which was stable up to 120 days. The MIC values for liposomal formulations and free VAN ranged from 0.78 to 1.56 µg/ml against both tested strains, with no difference in the inhibition of biofilm formation as compared to free VAN. However, when treating mature biofilm, encapsulated LUV fuso VAN increased the antimicrobial efficacy as compared to the other liposomal formulations and to free VAN, demonstrating a better ability to penetrate the biofilm. Conclusion: Vancomycin encapsulated in fusogenic liposomes demonstrated enhanced antimicrobial activity against mature S. aureus biofilms.

A. Uneputty, A. Dávila-Lezama, Diana Garibo et al.

Colloids and Interface Science Communications • 2021

Nearly a century has passed since the discovery of the first antibiotics. With each passing decade, more bacterial strains developed resistance towards existing antibiotics. Alternative methods to reduce contamination by bacteria and biofilms have arisen to reduce the pressure on existing or currently developed antibiotics. This review highlights promising approaches to prevent bacterial contamination of the surface. Special attention is paid to antibiotic-free antibacterial strategies that are not affected by bacterial resistance. The approaches have been divided into four categories: (i) anti-adhesive, (ii) contact active, and (iii) biocide attached/biocide release, which can be integrated with (iv) topographical modification. Anti-adhesive approaches can reduce the adhesion between bacteria and a solid surface to prevent bacteria from contacting and contaminating the surface. Contact active approaches provide antibacterial activity by attachment of antibacterial agents to the substratum. Biocide attached/biocide release integrates contact-release of toxic chemicals to bacteria attached to the surface. Lastly, topographical modification relies on approaches to produce small structural features capable of matching cellular components killing bacteria. Combining one or more antibacterial strategies can lead to a more robust approach to deal with dangerous pathogenic bacterial species. In this case, a way forward is by combining various coatings onto topographically modified surfaces, enabling multifunctionality to reduce adhesion and biofilm formation. A perspective on the current antibacterial surface challenge is provided.

Runlin Wang, Haozhe Zhang, Qiyu Liu et al.

Nature Communications • 2022

Understanding ion transport kinetics and electrolyte-electrode interactions at electrode surfaces of batteries in operation is essential to determine their performance and state of health. However, it remains a challenging task to capture in real time the details of surface-localized and rapid ion transport at the microscale. To address this, a promising approach based on an optical fiber plasmonic sensor capable of being inserted near the electrode surface of a working battery to monitor its electrochemical kinetics without disturbing its operation is demonstrated using aqueous Zn-ion batteries as an example. The miniature and chemically inert sensor detects perturbations of surface plasmon waves propagating on its surface to rapidly screen localized electrochemical events on a sub-μm-scale thickness adjacent to the electrode interface. A stable and reproducible correlation between the real-time ion insertions over charge-discharge cycles and the optical plasmon response has been observed and quantified. This new operando measurement tool will provide crucial additional capabilities to battery monitoring methods and help guide the design of better batteries with improved electro-chemistries.

A.H. Haidari, S.G.J. Heijman, Walter van der Meer

Separation and Purification Technology • 2017

<p>Spiral-wound membrane (SWM) modules are the most common membrane configuration utilized in reverse osmosis (RO) and nanofiltration. The enhancement of SWM module design, particularly in the geometric design of the feed spacer, can play a crucial role in the cost and the potential for wider application of these modules. The feed spacer influences the flux, pressure losses and fouling in the membrane process and consequently the product water unit cost. Despite the shift in the application of SWM modules of RO toward low salinity sources and the resulting higher sensitivity performance using these waters, the configuration and orientation of feed spacers have not significantly changed since the original design. A wider use of SWM modules, therefore, requires the adaptation of geometric parameters of the feed spacer to the water source. Improving the feed spacer's design according to the feed water type requires the knowledge of previous studies conducted in spacer-filled channels as well as further needed investigations in future. This paper reviews the role of the feed spacer in SWM modules and provides an overview of studies conducted in narrow spacer-filled channels to determine the effect of different geometric characteristics of the feed spacer on hydraulic conditions.</p>

Hanan Al‐Kutubi, Hamid Reza Zafarani, Liza Rassaei et al.

European Polymer Journal • 2016

Jieyuan Li, Ruimin Chen, Jielin Wang et al.

Nature Communications • 2022

The limitation of inert N 2 molecules with their high dissociation energy has ignited research interests in probing other nitrogen-containing species for ammonia synthesis. Nitrate ions, as an alternative feedstock with high solubility and proton affinity, can be facilely dissociated for sustainable ammonia production. Here we report a nitrate to ammonia photosynthesis route (NO 3 - RR) catalyzed by subnanometric alkaline-earth oxide clusters. The catalyst exhibits a high ammonia photosynthesis rate of 11.97 mol g metal -1 h -1 (89.79 mmol g cat -1 h -1 ) with nearly 100% selectivity. A total ammonia yield of 0.78 mmol within 72 h is achieved, which exhibits a significant advantage in the area of photocatalytic NO 3 - RR. The investigation of the molecular-level reaction mechanism reveals that the unique active interface between the subnanometric clusters and TiO 2 substrate is beneficial for the nitrate activation and dissociation, contributing to efficient and selective nitrate reduction for ammonia production with low energy input. The practical application of NO 3 - RR route in simulated wastewater is developed, which demonstrates great potential for its industrial application. These findings are of general knowledge for the functional development of clusters-based catalysts and could open up a path in the exploitation of advanced ammonia synthesis routes with low energy consumption and carbon emission.

Kecheng Quan, Jiapeng Hou, Zexin Zhang et al.

Critical Reviews in Microbiology • 2021

Bacterial biofilms occur in many natural and industrial environments. Besides bacteria, biofilms comprise over 70 wt% water. Water in biofilms occurs as bound- or free-water. Bound-water is adsorbed to bacterial surfaces or biofilm (matrix) structures and possesses different Infra-red and Nuclear-Magnetic-Resonance signatures than free-water. Bound-water is different from intra-cellularly confined-water or water confined within biofilm structures and bacteria are actively involved in building water-filled structures by bacterial swimmers, dispersion or lytic self-sacrifice. Water-filled structures can be transient due to blocking, resulting from bacterial growth, compression or additional matrix formation and are generally referred to as "channels and pores." Channels and pores can be distinguished based on mechanism of formation, function and dimension. Channels allow transport of nutrients, waste-products, signalling molecules and antibiotics through a biofilm provided the cargo does not adsorb to channel walls and channels have a large length/width ratio. Pores serve a storage function for nutrients and dilute waste-products or antimicrobials and thus should have a length/width ratio close to unity. The understanding provided here on the role of water in biofilms, can be employed to artificially engineer by-pass channels or additional pores in industrial and environmental biofilms to increase production yields or enhance antimicrobial penetration in infectious biofilms.

Lanhua Liu, Xuejun Zhang, Qian Zhu et al.

Light Science & Applications • 2021

The apparent increase in hormone-induced cancers and disorders of the reproductive tract has led to a growing demand for new technologies capable of detecting endocrine disruptors. However, a long-lasting challenge unaddressed is how to achieve ultrahigh sensitive, continuous, and in situ measurement with a portable device for in-field and remote environmental monitoring. Here we demonstrate a simple-to-implement plasmonic optical fiber biosensing platform to achieve an improved light-matter interaction and advanced surface chemistry for ultrasensitive detection of endocrine disruptors. Our platform is based on a gold-coated highly tilted fiber Bragg grating that excites high-density narrow cladding mode spectral combs that overlap with the broad absorption of the surface plasmon for high accuracy interrogation, hence enabling the ultrasensitive monitoring of refractive index changes at the fiber surface. Through the use of estrogen receptors as the model, we design an estradiol-streptavidin conjugate with the assistance of molecular dynamics, converting the specific recognition of environmental estrogens (EEs) by estrogen receptor into surface-based affinity bioassay for protein. The ultrasensitive platform with conjugate-induced amplification biosensing approach enables the subsequent detection for EEs down to 1.5 × 10 -3 ng ml -1 estradiol equivalent concentration level, which is one order lower than the defined maximal E 2 level in drinking water set by the Japanese government. The capability to detect EEs down to nanogram per liter level is the lowest limit of detection for any estrogen receptor-based detection reported thus far. Its compact size, flexible shape, and remote operation capability open the way for detecting other endocrine disruptors with ultrahigh sensitivity and in various hard-to-reach spaces, thereby having the potential to revolutionize environment and health monitoring.

Bogdan Butoi, Andreea Groza, P. Dincă et al.

Polymers • 2017

This work is focused on the structural and morphological investigations of polyaniline and poly( o -anisidine) polymers generated in a direct current glow discharge plasma, in the vapors of the monomers, without a buffer gas, using an oblique angle-positioned substrate configuration. By atomic force microscopy and scanning electron microscopy we identified the formation of worm-like interlinked structures on the surface of the polyaniline layers, the layers being compact in the bulk. The poly( o -anisidine) layers are flat with no kind of structures on their surfaces. By Fourier transform infrared spectroscopy we identified the main IR bands characteristic of polyaniline and poly( o -anisidine), confirming that the polyaniline chemical structure is in the emeraldine form. The IR band from 1070 cm -1 was attributed to the emeraldine salt form of polyaniline as an indication of its doping with H⁺. The appearance of the IR band at 1155 cm -1 also indicates the conducting protonated of polyaniline. The X-ray diffraction revealed the formation of crystalline domains embedded in an amorphous matrix within the polyaniline layers. The interchain separation length of 3.59 Å is also an indicator of the conductive character of the polymers. The X-ray diffraction pattern of poly( o -anisidine) highlights the semi-crystalline nature of the layers. The electrical conductivities of polyaniline and poly( o -anisidine) layers and their dependence with temperature are also investigated.

Tuan Guo

Micro-Structured and Specialty Optical Fibres V • 2018

Surface Plasmon resonance (SPR) optical fiber sensors can be used as a cost-effective and relatively simple-toimplement alternative to well established bulky prism configurations for in-situ high sensitivity biochemical and electrochemical measurements. The miniaturized size and remote operation ability offer them a multitude of opportunities for single-point sensing in hard-to-reach spaces, even possibly in vivo. Grating-assisted and polarization control are two key properties of fiber-optic SPR sensors to achieve unprecedented sensitivities and limits of detection. The biosensor configuration presented here utilizes a nano-scale metal-coated tilted fiber Bragg grating (TFBG) imprinted in a commercial single mode fiber core with no structural modifications. Such sensor provides an additional resonant mechanism of high-density narrow cladding mode spectral combs that overlap with the broader absorption of the surface Plasmon for high accuracy interrogation. In this talk, we briefly review the principle, characterization and implementation of plasmonic TFBG sensors, followed by our recent developments of the “surface” and “localized” affinity studies of the biomolecules for real life problems, the electrochemical actives of electroactive biofilms for clean energy resources, and ultra-highly sensitive gas detection.

Zhuo Chen, Ze Zhang, Rongxin Xia et al.

Energy & Fuels • 2025

To improve the conversion rate of carbon dioxide (CO2) to methane (CH4) in a microbial electrochemical system (MES), the zeolitic imidazolate framework ZIF-67(Co) with electron storage properties was first grown in situ on MIL-100(Fe) with excellent CO2 adsorption properties by a hydrothermal method. The obtained binary core–shell MIL@ZIF material was then adsorbed by carbon felt on a cathode to grow biofilms composed of electroactive microorganisms for characterization and testing in an MES. This system exhibited a CH4 production rate of 0.42 mmol LR–1 d–1, along with an impressive faradaic efficiency of 96.4%. Three-dimensional excitation–emission matrix spectra of extracellular polymeric substances indicated that those containing higher contents of humic acid shifted electron pairs and converted redox states to facilitate electron transfer. MIL@ZIF enriched hydrogenotrophic methanogens and electrogenic bacteria in microbial communities with enhanced gene expression of electrically conductive pili and cytochrome C to strengthen interspecies electron transfer. MIL@ZIF enhanced CO2 adsorption and electron storage, reinforcing electron transfer chains and boosting CH4 yield by a factor of 10.7.

Ghazal Shineh, Mohammadmahdi Mobaraki, Mohammad Jabed Perves Bappy et al.

Applied Microbiology • 2023

Biofilm formation can lead to problems in healthcare, water distribution systems, food processing and packaging, industrial manufacturing, marine industries, and sanitation. These microbial communities can proliferate on biotic or abiotic surfaces, and are responsible for human disease and decreasing production efficiency and service equipment life in many industrial fields. The formation of biofilm starts with the attachment of bacteria to the surface, followed by bacterial proliferation and maturation of the microbial community. After forming a biofilm, bacteria not resistant to antimicrobial agents in their planktonic forms can turn resistant. The antibiotic resistance of bacterial biofilm, and the association of biofilms in generating infectious diseases in humans, highlight the need for designing novel and successful antibacterial, anti-biofilm, or anti-infection materials. This paper aims to review the mechanism of biofilm formation, the impact on different industries, the interaction mechanism of nanoparticles with bacteria, and strategies to design anti-biofilm materials. Examples of designing anti-infection bio-implants, coatings, medical devices, wound dressings, and sutures are reviewed.

Philippe Refait, Anne‐Marie Grolleau, Marc Jeannin et al.

Corrosion and Materials Degradation • 2020

This article presents a synthesis of recent studies focused on the corrosion product layers forming on carbon steel in natural seawater and the link between the composition of these layers and the corrosion mechanisms. Additional new experimental results are also presented to enlighten some important points. First, the composition and stratification of the layers produced by uniform corrosion are described. A focus is made on the mechanism of formation of the sulfate green rust because this compound is the first solid phase to precipitate from the dissolved species produced by the corrosion of the steel surface. Secondly, localized corrosion processes are discussed. In any case, they involve galvanic couplings between anodic and cathodic zones of the metal surface and are often associated with heterogeneous corrosion product layers. The variations of the composition of these layers with the anodic/cathodic character of the underlying metal surface, and in particular the changes in magnetite content, are thoroughly described and analyzed to enlighten the self-sustaining ability of the process. Finally, corrosion product layers formed on permanently immersed steel surfaces were exposed to air. Their drying and oxidation induced the formation of akaganeite, a common product of marine atmospheric corrosion that was, however, not detected on the steel surface after the permanent immersion period.

Huang Zihan, Lei Zhang, Ting Cai et al.

Engineering Microbiology • 2025

Polycyclic aromatic sulfur heterocycles, such as dibenzothiophene (DBT), and their alkylated derivatives are recognized as persistent and toxic contaminants that pose major risks to the environment and human health. Here, a novel electroactive gram-positive bacterium, Lysinibacillus macroides AP, was isolated and identified from a microbial fuel cell (MFC) powered by aromatic compounds. An electricity generation performance with a maximum discharge voltage of 424.59 mV and a power density of 420.95 mW m⁻ 2 was obtained using L. macroides AP in an MFC fueled with sodium formate. An analysis of the extracellular electron transfer (EET) mechanism indicated that the endogenous redox mediators produced by L. macroides AP were not detected, but exogenous redox mediators such as thionine acetate and anthraquinone-2, 6-disulfonate could temporarily enhance EET. The characterization of biofilm morphology revealed a dense network of microbial nanowires on the cell surface of L. macroides AP; the abundance of these nanowires was positively correlated with the discharge efficiency of the MFC, suggesting that the nanowires generated by L. macroides AP cells were likely to promote EET. Additionally, effective bioelectricity generation and simultaneous DBT degradation were successfully achieved using L. macroides AP in MFCs, with a power density of 385.20 mW m⁻ 2 and 88.72 % DBT removal. This is the first report on a novel ecological role of L. macroides AP as a gram-positive electroactive bacterium, emphasizing its potential applications in environmental remediation and energy recovery.

Hui Shi, Ziqi Zhou, Wuda Li et al.

Crystals • 2021

Hydroxyapatite (HA) is widely used in bone tissue engineering for its bioactivity and biocompatibility, and a growing number of researchers are exploring ways to improve the physical properties and biological functions of hydroxyapatite. Up to now, HA has been used as inorganic building blocks for tissue engineering or as nanofillers to blend with polymers, furthermore, various methods such as ion doping or surface modification have been also reported to prepare functionalized HA. In this review, we try to give a brief and comprehensive introduction about HA-based materials, including ion-doped HA, HA/polymer composites and surface modified HA and their applications in bone tissue engineering. In addition, the prospective of HA is also discussed. This review may be helpful for researchers to get a general understanding about the development of hydroxyapatite based materials.

Ping-Ching Wu, Hua-Han Chen, Shih‐Yao Chen et al.

Journal of Nanobiotechnology • 2018

Graphene oxide is not an antimicrobial material but it is a general growth enhancer that can act as a biofilm to enhance bacterial attachment and proliferation. However, GO-based materials are capable of inducing ROS-dependent oxidative stress on bacteria. The applications of GO-based materials can clearly be used in antimicrobial surface coatings, surface-attached stem cells for orthopedics, antifouling for biocides and microbial fuel cells and microbial electro-synthesis.

Falk Harnisch, Benjamin Korth

Joule • 2021

Myeonggyun Kim, C. S. Park, Seo-Gyeong Bae et al.

Environmental Research • 2025

Zhonghao Wan, Zibo Xu, Yuqing Sun et al.

Environmental Science & Technology • 2021

Nitrogen-doped graphitic biochar (NBC) has boosted the development of nonradical peroxymonosulfate (PMS) activation in environmental remediation. However, the specific role of nitrogen species played in NBC-based nonradical carbocatalysis remains vaguely interpreted. To pinpoint the critical nitrogen speciation, a sophisticated thermo-mechanochemical manipulation was exploited to prepare a series of NBCs with similar dimensional structures and oxygen levels but different nitrogen species ( i . e ., dopants and vacancies). Different from conventional perspectives, nonradical NBC-based carbocatalysis was found to be preferably determined by the nitrogen vacancies more than their parent nitrogen dopants. Raman depth analysis evidenced that a complete transformation of nitrogen dopants into nitrogen vacancies could be achieved at 800 °C, where an excellent nonradical abatement of 4-chlorophenol (4-CH, 90.9% removal) was found for the NBC800 with a low PMS consumption (1.24 mM). According to PMS adsorption experiments, nitrogen vacancies exhibited the highest affinity toward the PMS molecules compared to nitrogen dopants, which accounted for the superior carbocatalysis. Electron paramagnetic resonance and Raman spectroscopic analyses indicated that the original PMS molecules were bound to positively charged nitrogen vacancies, and a robust metastable complex (*HSO 5 - ) evolved subsequently via hydrogen abstraction by adjacent persistent free radicals. In situ Raman techniques could be adopted to estimate the level of nitrogen vacancies associated with the polarization of electron distribution. The flexible feature and practical prospects of nitrogen vacancy-based carbocatalysis were also observed in the remediation of simulated phenolic industrial wastewater. Overall, this study unravels the dilemma in the current NBC-based nonradical carbocatalysis and advances our understanding of nitrogen doping technology for next-generation biochar design.

Florence Pilate, Antoniya Toncheva, Philippe Dúbois et al.

European Polymer Journal • 2016

Gaojun Wang, Bo Zhang, Changxi Sun et al.

Journal of Water Process Engineering • 2024

This study investigated the separate and coupling strategies of biochar addition or/and electric field stimulation on anaerobic digestion (AD) of food waste slurry (FWS). Both biochar and electric field stimulation accelerated AD start-up, and the coupling strategy promoted volatile fatty acids (VFA) oxidation and methanogenesis, leading to a 34.1 % increase in accumulated methane yield during a 50-day operation period. Microbial characterization analysis revealed that biochar primarily upregulated the secretion of protein-like compounds in tightly-bound extracellular polymeric substances, and the electroactive matrix involving bulk sludge and biochar was likely established to mediate syntrophic methanogenesis through extracellular electron transfer (EET). Comparatively, electric field mainly governed the electrochemical behaviors and microbial community evolution of the electrode biofilm, which boosting the electrochemical activity of both anode and cathode, and increasing the cell viability of cathodic biofilm. It also selectively enriched Syntrophomonas in the anode and filamentous Methanospirillum in the cathode, which contributed to syntrophic methanogenesis in the electric stimulation groups. Overall, the outcome of this research underlined the different roles of biochar and electric field in boosting methanogenesis, and confirmed the synergistic benefits of the coupling stimulation strategy. • Biochar addition coupling electric stimulation facilitates accumulated CH 4 production by 34.1 % • Regulatory roles of biochar and electric field to boost methanogenesis are distinguished. • Biochar stimulates protein-like EPS secretion of bulk sludge to mediate EET-based methanogenesis. • The electric field harnesses cathodic biofilm formation by enriching filamentous Methanospirillum .

Ehsan Shirzaei Sani, Changhao Xu, Canran Wang et al.

Science Advances • 2023

Chronic nonhealing wounds are one of the major and rapidly growing clinical complications all over the world. Current therapies frequently require emergent surgical interventions, while abuse and misapplication of therapeutic drugs often lead to an increased morbidity and mortality rate. Here, we introduce a wearable bioelectronic system that wirelessly and continuously monitors the physiological conditions of the wound bed via a custom-developed multiplexed multimodal electrochemical biosensor array and performs noninvasive combination therapy through controlled anti-inflammatory antimicrobial treatment and electrically stimulated tissue regeneration. The wearable patch is fully biocompatible, mechanically flexible, stretchable, and can conformally adhere to the skin wound throughout the entire healing process. Real-time metabolic and inflammatory monitoring in a series of preclinical in vivo experiments showed high accuracy and electrochemical stability of the wearable patch for multiplexed spatial and temporal wound biomarker analysis. The combination therapy enabled substantially accelerated cutaneous chronic wound healing in a rodent model.

Rafaella Marcílio, Sidney Aquino Neto, Bruno Martins Ruvieri et al.

Brazilian Journal of Chemical Engineering • 2021

Laura Mais, Jesús Rodríguez, Roberto Campana et al.

Journal of Power Sources • 2025

A 3D mathematical model has been applied to a tubular MFC with ceramic separators that were fabricated by slip-casting. The system features a carbon felt anode and a carbon-based cathode with a mixture of activated carbon and carbon black as catalyst. Electricity generation and substrate removal were first experimentally investigated with the cell operating in fed-batch mode. The cell was also characterised using polarisation experiments and electrochemical impedance spectroscopies (EIS). Experimental results were used to calibrate the model and obtain the kinetics parameters for biofilm formation, as well as bioelectrochemical and electrochemical reactions. The model has been solved to represent the system under the conditions used in the experiments with a good fitting of the data. The evolution of biofilm thickness and profile of concentration of substrate with time calculated with the model are presented and discussed. The model was also used to simulate different scenarios and has been proven to be a versatile tool for designing and optimising the investigated system. • 3D model applied to tubular microbial fuel cell with ceramic separator. • Electroactive biofilm formation boosts electricity generation. • Electrochemical Impedance Spectroscopy used for system characterization. • Model accurately predicts biofilm thickness and substrate depletion.

Ye Yuan, J. Zhang, Liang-Long Xing

International Journal of Environmental Science and Technology • 2019

Meng Yu, Wenzheng Wang, Pengjie Wu et al.

Electrocatalysis • 2024

Mankun Li, Junye Zhou, Yaqiang Li et al.

Bioelectrochemistry • 2024

Tao Li, Chenying Li, Yanfei Wang et al.

Journal of Hazardous Materials • 2024

Laura Galezowski, Nadir Recham, Dominique Larcher et al.

Microorganisms • 2023

Mn(II)-oxidizing organisms promote the biomineralization of manganese oxides with specific textures, under ambient conditions. Controlling the phases formed and their texture on a larger scale may offer environmentally relevant routes to manganese oxide synthesis, with potential technological applications, for example, for energy storage. In the present study, we sought to use biofilms to promote the formation of electroactive minerals and to control the texture of these biominerals down to the electrode scale (i.e., cm scale). We used the bacterium Pseudomonas putida strain MnB1 which can produce manganese oxide in a biofilm. We characterized the biofilm-mineral assembly using a combination of electron microscopy, synchrotron-based X-ray absorption spectroscopy, X-ray diffraction, thermogravimetric analysis and electron paramagnetic resonance spectroscopy. Under optimized conditions of biofilm growth on the surface of current collectors, mineralogical characterizations revealed the formation of several minerals including a slightly crystalline MnOx birnessite. Electrochemical measurements in a half-cell against Li(0) revealed the electrochemical signature of the Mn 4+ /Mn 3+ redox couple indicating the electroactivity of the biomineralized biofilm without any post-synthesis chemical, physical or thermal treatment. These results provide a better understanding of the properties of biomineralized biofilms and their possible use in designing new routes for one-pot electrode synthesis.