Excellent Antibacterial Properties Research Articles

New emerging materials with potential antibacterial activities.

The increasing prevalence of multidrug-resistant pathogens is a critical public health issue, necessitating the development of alternative antibacterial agents. Examples of these pathogens are methicillin-resistant Staphylococcus aureus (MRSA) and the emergence of "pan-resistant" Gram-negative strains, such as Pseudomonas aeruginosa and Acinetobacter baumannii, which occurred more recently. This review examines various emerging materials with significant antibacterial activities. Among these are nanomaterials such as quantum dots, carbon quantum dots, metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and layered double hydroxides, all of which demonstrate excellent antibacterial properties. Interestingly, including antibacterial agents within the structure of these materials can help avoid bacterial resistance and improve the long-term efficacy of the materials. Additionally, the antibacterial potential of liquid solvents, including ionic liquids and both deep eutectic solvents and natural deep eutectic solvents, is explored. The review discusses the synthesis methods, advantages, and antibacterial efficacy of these new materials. By providing a comprehensive overview of these innovative materials, this review aims to contribute to the ongoing search for effective solutions to combat antibiotic resistance. Key studies demonstrating antibacterial effects against pathogens like Escherichia coli, Staphylococcus aureus, and multidrug-resistant strains are summarized. MOFs have exhibited antibacterial properties through controlled ion release and surface interactions. COFs have enhanced the efficacy of encapsulated antibiotics and displayed intrinsic antibacterial activity. Other nanomaterials, such as quantum dots, have generated reactive oxygen species, leading to microbial inactivation. This review aims to provide insights into these new classes of antibacterial materials and highlight them for addressing the global crisis of antibiotic resistance. KEY POINTS: • Nanomaterials show strong antibacterial effects against drug-resistant bacteria • Emerging solvents like ionic liquids offer novel solutions for bacterial resistance • MOFs and COFs enhance antibiotic efficacy, showing promise in combating resistance.

Preparation and properties of polytetrafluoroethylene/zinc oxide antibacterial filaments

AbstractThe potential of polytetrafluoroethylene (PTFE) products as surgical dressings is considerable, yet their absence of antibacterial properties substantially restricts their medical applications. To enhance the utility of PTFE in the medical sector, this research loaded nano zinc oxide (ZnO) particles into the PTFE filament matrix through a wet spinning process. This approach successfully yielded PTFE/ZnO composite filaments with antibacterial properties. The characterization results of the filaments show that when the mass ratio of PTFE to ZnO is 8:1, the filament has the best mechanical performance with a tensile strength of 6.78 MPa and an elongation at break of 274.46%. At the same time, composite antibacterial filaments under different process conditions show excellent antibacterial effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with an antibacterial rate of over 99%. The excellent mechanical properties ensure the ability to further process single filaments, which can be woven into fabrics, textiles, and various other products. Therefore, the composite antibacterial filaments with excellent comprehensive performance prepared in this study are expected to be applied in the field of medical fabrics.Highlights Provide new solution ideas for functional PTFE composite filaments preparation. The prepared PTFE/ZnO composite filament has good acid and alkali resistance as well as excellent antibacterial properties, which is expected to broaden the application field of PTFE filaments.

Enhancing Strawberry Freshness: Multifunction Sustainable Films Utilizing Two Types of Modified Carbon Nanotubes for Photothermal Food Packaging.

Currently, antimicrobial films with stable and efficient antibacterial activities are receiving considerable attention in the food packaging industry. Herein, a chemically/physically linked konjac glucomannan-sodium alginate (KGM-SA)@carbon nanotubes (CNTs)/Fe3+ composite film with outstanding resistance to ultraviolet radiation, oxidation, and bacteria, as well as excellent photothermal effects and mechanical properties, was successfully prepared using a solvent flow method. Tannic acid-modified carboxyl-functionalized CNTs (TCCNTs), l-cysteine-modified carboxyl-functionalized CNTs (LCCNTs), and Fe3+ were incorporated into the prepared film. The film structure of KGM-SA@CNTs/Fe3+ was characterized using various methods, confirming the formation of a dual-cross-linked network through metal-coordination bonds and hydrogen bonding. This unique structure endowed the film with excellent water vapor permeability (3.58 g mm/m2 day kPa), water resistance (water contact angle = 93.66°), and thermal stability. Further, the film exhibited outstanding photothermal conversion efficiency and stability under near-infrared irradiation (300 mW/cm2) as well as excellent bactericidal properties against Staphylococcus aureus and Escherichia coli, achieving a bacterial inhibition rate of >99%. In a strawberry preservation experiment, the KGM-SA@CNTs/Fe3+ composite film exhibited remarkable preservation effects, extending the shelf life of strawberries by 4-6 d. Thus, this photothermal antibacterial film offers a new approach for the application of CNTs in food packaging.

Multifunctional composite paper fabricated by graphene oxide/tannin decorated carbon fiber with excellent electromagnetic interference shielding, antibacterial and sound absorption properties

Considering the distinctive oxidative coupling characteristic of tannin acid, it was used as an interfacial interlayer to build a nano-coating structure on the surface of carbon fiber (CF)using amino-modified graphene oxide (GON) via Schiff base reaction. Furthermore, a kind of multifunctional composite paper (PTCF/GON) with excellent electromagnetic interference shielding, antibacterial and sound absorption properties was fabricated using surface modified CF (TCF/GON) and plant fibers. The increased active groups on the surface of TCF/GON improved its hydrophilicity and enhanced its dispersibility in water, which facilitated to form an effective interconnected conductive network of composite paper via traditional wet forming process. Composite paper fabricated by 30 wt% surface decorated CF (PTCF1.5/GON1.2) achieved an electromagnetic interference shielding effectiveness as high as 43.4 dB in X-band, shielding 99.9 % of incident electromagnetic energy. Meanwhile, PTCF1.5/GON1.2 exhibits good sound absorption performance in specific frequency bands, with a sound absorption coefficient of 0.98 around 1180 Hz. Besides, PTCF1.5/GON1.2 also exhibited excellent antibacterial properties. This strategy provides an economical and practical method for manufacturing multifunctional electromagnetic shielding materials with superior performance.

Flexible antibacterial strain sensor with low electrical hysteresis, ultralow detection limit, and wide linear sensing range for human motion monitoring and human–machine interaction

Achieving low electrical hysteresis, an ultralow detection limit, and a wide linear sensing range is critical for the practical application of flexible strain sensors. However, the intrinsic viscoelasticity of the elastomer macromolecules can adversely affect the behavior of the conductive sensing network during stretching and relaxation, rending it challenging to simultaneously achieve these properties. Herein, a novel strategy is proposed to design a hybrid covalent-ionic crosslinking network within the elastomer and to construct a robust conductive carbon nanotube (CNT) layer on the elastomer surface using a swelling-driven penetration method. The hybrid crosslinking network gives the elastomer enhanced mechanical strength and exceptional stretchability, while reducing the dynamic losses of the macromolecules. It also reduces the impact of the elastomer macromolecules on the conductive layer during stretching. Even minimal strains are sufficient to induce slippage of the CNTs, leading to changes in resistance. As the strain increases, further disentanglement and slippage of the CNTs results in crack formation, which enables greater resistance variation and dominates the sensing mechanism. As a result, the as-prepared conductive elastomer-based strain sensors exhibit exceptional sensing performance, including low electrical hysteresis (2.3 %), ultralow detection limit (0.1 %), wide linear working range (690 %), and excellent durability (>10,000 cycles). The strain sensors have been successfully employed in human motion monitoring, human–machine interaction, and angle measurement. In addition, the incorporation of the ionic crosslinking network endows the sensor with excellent antibacterial properties. Consequently, the developed conductive elastomers hold significant promise for applications in smart wearable electronics.

An integrally formed Janus supramolecular bio-gel with intelligent adhesion for multifunctional healthcare

Despite the rapid development of Janus adhesive hydrogels, most of them still entail complex fabrication processes and have the inherent flaws, such as fragility and instability, thereby restricting their biomedical applications. In this study, a novel Janus bio-gel with strong mechanical and intelligent adhesion functions is facilely fabricated through a gravity-driven settlement strategy, employing poly-cyclodextrin microspheres (PCDMs). This strategy takes advantage of the sedimentation behavior of PCDMs with various diameters to establish structural disparities on both sides of the Janus bio-gel, thereby resolving multiple predicaments including the tedious synthesis steps and poor bonding of multilayer hydrogels. Owing to the multiple dynamic interactions between polymers and PCDMs, the Janus supramolecular bio-gel demonstrates outstanding mechanical toughness (1.97 MJ/m3) and elongation rate (≈800 %). More attractively, the resulting Janus bio-gel exhibits remarkable adhesiveness (316.4 J/m2 for interfacial toughness) and adhesive differences that are exceed 50 times between the two surfaces. Furthermore, the Janus supramolecular bio-gel also has excellent antibacterial properties, biocompatibility, environmental stability, and multiple monitoring functions, accelerating wound stably healing and monitoring physiologic parameters on the skin. This strategy provides a straightforward and promising approach to directly achieve multifunctional integration for smart health management.

A self-sufficient catalytic nanofiber evaporator for solar-driven efficient water purification through in-situ hydrogen peroxide generation

Solar-driven interfacial water evaporation (SDIWE) is an emerging technology for the production of clean water driven by inexhaustible energy source, but its application suffers from volatile organic compounds (VOCs) escaping into condensate water. Herein, a bifunctional SDIWE system integrated with Fenton process was proposed to achieve self-sufficient (not adding any additional chemicals to feed water) high-quality freshwater production from VOCs-contained wastewater through in-situ hydrogen peroxide (H2O2) generation. The hybrid SDIWE system based on AgNPs (Ag nanoparticles)@graphitic carbon nitride (g-C3N4)/beta-iron hydroxide oxide (β-FeOOH)-Polyacrylonitrile (AgG/Fe-PAN) nanofiber membrane exhibited an excellent evaporation performance (1.61 kg m-2h−1) under one sun (1 kW m−2). Significantly, in the absence of external oxidant source, the phenol removal rate in condensate water reached 98.4 ± 0.2 % due to the synergic photocatalysis technology and Fenton reaction, which was 6.1 times that of sole SDIWE (16.2 ± 0.5 %). Mechanism analysis reveals that H2O2 was effectively in-situ generated by AgNPs@g-C3N4 particles (∼18.8 μM at 4 h). Subsequently, the produced H2O2 was further activated to •OH radicals via β-FeOOH that ensures the VOCs decomposition during rapid steam generation. Meanwhile, the hybrid system not only exhibited an excellent phenol removal rate of 91.6 ± 0.6 % in wide pH ranges (1–11), but also ensured a good removal performance for various organic pollutants and excellent antibacterial properties. To sum up, the hybrid system has successfully integrated SDIWE technology with various advanced oxidation processes (AOPs), providing a novel way for the pollution-free production of high-quality clean water during the SDIWE process for water purification.

Antibacterial carboxymethyl chitosan hydrogel loaded with antioxidant cascade enzymatic system for immunoregulating the diabetic wound microenvironment

Diabetic wound healing faces several complex challenges, such as hypoxia, oxidative stress, and bacterial infections, which severely inhibit the wound-healing process. Herein, a quaternary ammonium salt-crosslinked carboxymethyl chitosan hydrogel (TPC) with excellent antioxidant and antibacterial properties was developed to immunoregulate the diabetic wound microenvironment. The TPC hydrogel was prepared by first mixing carboxymethyl chitosan (CMCS) and protocatechualdehyde (PA), followed by the addition of a quaternary ammonium cross-linker (TSPBA) and a superoxide dismutase (SOD)–catalase (CAT) cascade system. The immobilized SOD and CAT retained their activity, continuously converting endogenous ·O2− and H2O2 to O2 and H2O. PA also provided the TPC hydrogel excellent oxygen and nitrogen radical scavenging capacity. The quaternary ammonium groups in TSPBA significantly enhanced the inherent antibacterial ability of CMCS-based hydrogels. In diabetic wound-healing experiments, this porous and adhesive TPC hydrogel effectively closed wounds and regenerated skin tissue, resulting in shorter wound edges, thicker granulation, and higher collagen deposition levels compared with other groups. The TPC hydrogel also promoted macrophage polarization toward the M2 phenotype, accelerating wound healing by upregulating IL-10 expression, downregulating IL-6 expression, and enhancing angiogenesis. These results demonstrate the great potential of TPC hydrogel as a promising therapeutic dressing for treating diabetic wounds.

A novel fine-grained TiZrCu alloy tailored for marine environment with high microbial corrosion-resistance

Titanium alloys, usually known as non-corrodible material, are susceptible to microbiologically influenced corrosion (MIC) in marine environment. While titanium-zirconium (TiZr) alloys have been extensively studied in medical applications, the influence of microorganisms, especially marine microorganisms, on their corrosion behavior has not been explored. In this work, a TiZrCu alloy with a combination of excellent mechanical, anti-corrosion, and antibacterial properties was developed by optimizing the Cu content and grain refinement. Its MIC and antibacterial mechanisms against Pseudomonas aeruginosa, a representative marine microorganism, were systematically investigated. 5.5 wt% was determined as the optimal copper content. The fine-grained Ti-15Zr-5.5Cu (TZC-5.5FG) alloy maintained high MIC resistance, exhibiting a corrosion current of 5.7 ± 0.1 nA/cm2 and an antibacterial rate of 91.8 % against P. aeruginosa. The mechanism of improved corrosion resistance was attributed to the denser passive film with high TiO2 content and the lower surface potential difference ΔE. The release of Cu2+ ions, ΔE, and the generation of ROS are three major factors that contribute to the antibacterial performance of TiZrCu alloys. Compared to other available marine metals, TZC-5.5FG alloy exhibited superior comprehensive performance, including excellent mechanical properties and anti-MIC capacity, which make it a promising material for load-bearing applications in marine environment.

Antibacterial and biological properties of MAO treated Mg-Bi alloys

The clinical application of Mg implant is limited due to the poor corrosion resistance, antibacterial and biological properties. In our previous work, Mg-Bi alloy with micro-arc oxidation (MAO) treatment was prepared and proved to have good corrosion resistance, so in this work, their antibacterial property and bioactivity were also investigated to evaluate its potential application in clinics. The results showed that, the Mg-Bi alloy has good antibacterial performance, and with the increase of Bi content, the antibacterial property was enhanced. After MAO treatment, the antibacterial performance was slightly decreased, however the MAO-Mg-6Bi and MAO-Mg-9Bi still showed excellent antibacterial property, additionally, they can also induce apatite formation in simulated body fluid (SBF), indicating improved bioactivity. Based on the good comprehensive properties, the MAO treated Mg-Bi alloy has a great potential to be used as an implant material in clinics.

Bimetallic FeCo metal–organic framework based cascade reaction system: Enhanced peroxidase activity for antibacterial performance

Metal-organic frameworks (MOFs), as a peroxidase (POD), can catalyze the conversion of H2O2 to reactive oxygen species (ROS) for antibacterial application. To achieve strong antibacterial activity, it is necessary to improve the enzyme-like activity of MOFs. In this study, FexCoMOF was synthesized by incorporating Co(II) to improve the electron transfer of Fe(III)/Fe(II), which enhanced its redox capacity as a nanozyme and further promoted the generation of hydroxyl radical (⋅OH), exhibiting higher POD activity. Doping with different amounts of Co(II) altered the particle size, specific surface area, and surface defects of FexCoMOF, thus exhibiting differential enzyme-like activities. Additionally, a glucose-responsive enzyme cascade reaction system based on Fe4CoMOF/glucose oxidase (GOx) was established. In the presence of glucose, the in situ-generated substrate H2O2 was in contact with the catalytic site and the generated gluconic acid enabled Fe4CoMOF to maintain maximum enzyme activity under physiological pH conditions, avoiding damage caused by the use of exogenous high concentrations of H2O2. In the in vitro antibacterial experiment, the minimum inhibitory concentration (MIC) of Fe4CoMOF/GOx was 10 μg mL−1 for Escherichia coli (E. coli) and 5 μg mL−1 for Staphylococcus aureus (S. aureus) (∼108 CFU mL−1). The increase in enzyme activity resulted in a considerable reduction in the dose of the antibacterial agent, which was conducive to improving bio-safety. The in vivo experiment in mice demonstrated that the glucose-responsive Fe4CoMOF-based cascade reaction system had excellent antibacterial properties and remarkably promoted wound healing. The antibacterial agent based on bimetallic MOF developed in this work provides a new idea for cascade catalytic antibacterial therapy and will have remarkable application prospects in biomaterials and nanomedicine.

A triple-mode strategy combining low-temperature photothermal, photodynamic, and chemodynamic therapies for treating infectious skin wounds.

The skin is the first natural barrier of the human body. Bacterial infections severely hinder the healing process of skin wounds and pose a great threat to human health. Therefore, it is particularly urgent to develop new antimicrobial strategies for bacterial pathogen clearance and wound healing. In this study, a metal-organic framework (MOF), Fe-MIL88B-NH2, was incorporated with the photosensitizer indocyanine green (ICG) to construct composite nanoparticles (MOF@ICG NPs) with multiple antibacterial activities. Under mild near-infrared (NIR) irradiation, the photosensitizer ICG in the MOF@ICG NPs undergoes photothermal conversion (∼45 °C) and photodynamic reactions to generate heat and singlet oxygen (1O2). In addition, the Fenton reaction of the NPs with hydrogen peroxide (H2O2) in the bacterial infection microenvironment resulted in the generation of hydroxyl radicals (˙OH), thus achieving the three-mode combination of low-temperature photothermal therapy (PTT)/photodynamic therapy (PDT)/chemodynamic therapy (CDT). The in vitro experimental results showed that MOF@ICG MPs had excellent antibacterial properties and good cytocompatibility, with some ability to promote the migration of L-929 fibroblasts. Furthermore, under NIR irradiation, MOF@ICG NPs could significantly kill bacteria and promote skin wound healing according to the results of animal experiments. The wound healing rate reached 87.1% after 7 days of treatment. The research results break through the limitations of single-mode antibacterial technology and provide certain theoretical guidance and technical support for the research and development of new antibacterial materials.

Utilizing Ziziphus spina-christi for eco-friendly synthesis of silver nanoparticles: Antimicrobial activity and promising application in wound healing

Abstract Wound healing is a critical process essential for the body’s recovery from injuries, often complicated by bacterial infections. Silver nanoparticles (AgNPs) have gained attention due to their antibacterial and tissue-regenerative properties. However, conventional chemical synthesis methods for AgNPs pose environmental risks. This study utilizes Ziziphus spina-christi (ZSC) extract for the eco-friendly synthesis of AgNPs, evaluating their antibacterial and wound-healing capabilities. The AgNPs-ZSC showed an absorption maximum at λ max of 460 nm, a particle size of 111.2 ± 1.09 nm, a polydispersity index of 0.38 ± 0.006, and a zeta potential of −27.0 ± 0.231 mV. The synthesized AgNPs-ZSC were spherical, non-aggregated, and exhibited potent antibacterial activity superior to chloramphenicol. Furthermore, the AgNPs-ZSC cream significantly promoted wound closure, epithelial tissue proliferation, and granulation tissue formation in rats, showing no signs of toxicity or adverse reactions. In conclusion, AgNPs-ZSC cream demonstrates excellent antibacterial and wound-healing properties, presenting a sustainable alternative to conventional chemical methods for AgNP synthesis.

Construction of Co-Modified MXene/PES Catalytic Membrane for Effective Separation and Degradation of Tetracycline Antibiotics in Aqueous Solutions.

The application of antibiotics has advanced modern medicine significantly. However, the abuse and discharge of antibiotics have led to substantial antibiotic residues in water, posing great harm to natural organisms and humans. To address the problem of antibiotic degradation, this study developed a novel catalytic membrane by depositing Co catalysts onto MXene nanosheets and fabricating the polyethersulfone composite (Co@MXene/PES) using vacuum-assisted self-assembly. The dual role of MXene as both a carrier for Co atoms and an enhancer of interlayer spacing led to improved flux and catalytic degradation capabilities of the membrane. Experimental results confirmed that the Co@MXene/PES membrane effectively degraded antibiotics through peroxymonosulfate activation, achieving up to 95.51% degradation at a cobalt concentration of 0.01 mg/mL. The membrane demonstrated excellent antibacterial properties, minimal flux loss after repeated use, and robust anti-fouling performance, making it a promising solution for efficient antibiotic removal and stable water treatment.

Bacterial inhibition and biofilm eradication ability of low-toxic deep eutectic solvents prepared from lactic acid and quaternary ammonium compounds

In the present communication, the preparation of deep eutectic solvents (DESs) based on an aqueous solution of lactic acid (LA) and two different quaternary ammonium compounds, choline chloride (ChCl) and tetraethylammonium chloride (TEAC), is proposed for the application as an antibacterial agent. The antibacterial and cytotoxic properties of the DESs obtained were studied and found to be highly effective in inhibiting both Gram-positive and Gram-negative bacteria and eradicating bacterial biofilms. Moreover, the DESs obtained exhibited reduced cytotoxicity towards soft tissue cells compared to the aqueous LA solution. The excellent antibacterial properties and low cytotoxicity of the DESs prepared make them a promising candidate for the development of novel antimicrobial agents or antibacterial eutectogels for delivery systems and tissue engineering applications.

Self-gelling, tunable adhesion, antibacterial and biocompatible quaternized cellulose/tannic acid/polyethylene glycol/montmorillonite composite powder for quick hemostasis

Hemostatic powders are widely used in incompressible or irregularly shaped bleeding wounds, but traditional hemostatic powders exhibit low adhesion, unsatisfactory hemostatic effect, limited infection control, and are not suitable for clinical or emergency situations. This study developed a novel self-gelling hemostatic powder (QTPM) consisting of quaternized cellulose (QC)/ tannic acid (TA)/ polyethylene glycol (PEG)/ montmorillonite (MMT). QTPM could absorb interfacial liquid hydrating to a stable hydrogel which form a switchable adhesion to tissues. Moreover, QTPM exhibits excellent antibacterial property by the synergistic effect of QC and TA. Furthermore, QTPM directly activate intrinsic and extrinsic coagulation hemostatic pathways to enhance hemostasis, and it concentrate coagulation factors. In vivo hemostasis study results show that QTPM significantly accelerated hemostasis and reduced blood loss compared with the blank group (>75 % reduction in hemostatic time, >85 % reduction in blood loss) in liver bleeding model (hemostasis time of 71.67 ± 7.09 s, blood loss of 19.23 ± 2.60 mg) and tail amputation model (hemostasis time of 91.03 ± 12.05 s, blood loss of 15.24 ± 1.77 mg). Therefore, the advantages of QTPM including rapid and effective hemostasis, easy usage, easy storability and adaptability make it a potential biomaterial for rapid hemostasis direction in the clinical setting.

Highly Stretchable Sensitive Multiscale Hydrogel Inspired by Biological Muscles for Wearing Sensors.

Hydrogels have attracted substantial research interest for application in wearable electronics due to their stretchability, elasticity, and compliance. However, most hydrogels could not satisfy the application requirements for high-performance wearable sensors due to their poor sensitivity, low mechanical properties, and sensing detection range until this day. Inspired by the fascia in biological muscles, we propose a strategy to form entangled "clusters" through the dense entanglement between highly cross-linked elastic hydrogel microspheres and polymer segments, and prepared a multiscale hydrogel with high sensitivity and mechanical toughness. This strategy embedded highly swollen hydrogel microspheres (with different pore sizes) to act as the microregions of dense entanglement in the soft matrix to adjust the microstructure of multiscale gel. When pressure was applied, this structure could provide a fast response due to the stack layer formed by microspheres and soft matrix produced effective stress distribution, resulting in the outstanding sensitivity of the multiscale hydrogel (S = 1.1 kPa-1) in the pressure range of 0-50 kPa. The distinct microspheres functioning as microscale joint areas significantly augment energy dissipation, culminating in exceptional mechanical stability, ultrastretchability (≈1050%), and high strength of the multiscale hydrogel. The most notable progress was that the synthesized multiscale hydrogel not only combined the above advantages but also simultaneously solved multiple dilemmas of tedious synthesis steps, high cost, and poor durability. Besides, the multiscale hydrogel also had excellent antibacterial properties and biocompatibility, which enabled them to have large-scale application potential in wearable and implantable electronic devices. Our research could provide a universal approach to the creation of robust, flexible, wearable, and sensitive sensors, significantly increasing the uses of stress sensors in wearable technology.

Surface Molding Hydrogel Film Initiated by ZIF-8 with Ethylene Adsorption Performance for Preserving Perishable Fruits.

The quality deterioration of postharvest fruits is greatly influenced by ethylene, leading to food wastage worldwide. Therefore, it is urgent to develop an efficient packaging strategy to reduce ethylene concentration and prolong the shelf life of perishable fruits. In this work, a surface-molding hydrogel film was created using ZIF-8 in combination with carboxymethyl starch (CMS) and carboxymethyl chitosan (CMCS). Specifically, ZIF-8 is first anchored on CMS and then rapidly cross-linked in situ with CMCS, forming ZIF-8@CC on the fruit surface (within 10 s). The perfect tight-fitting effects of ZIF-8@CC were observed on various fruit surfaces with different roughness (Ra: ranges from 102 to 308 nm). ZIF-8@CC could absorb 57.3% endogenous ethylene from bananas, and the interaction mechanism between ethylene and ZIF-8 was studied by molecular dynamics simulations, providing insights into the ethylene adsorption capacity of ZIF-8@CC. Moreover, ZIF-8@CC presented excellent antibacterial properties and achieved satisfactory ultralong preservation effects on both nonclimatic and climatic fruits (12 days for strawberries and 14 days for bananas) at room temperature. Importantly, ZIF-8@CC is easily removed, washed, and degradable. These findings offer an efficient and potential food packing material with multifunctional properties for preserving perishable fruits.

Polydopamine-based surface coating fabrication on titanium implant by combining a photothermal agent and TiO2 nanosheets for efficient photothermal antibacterial therapy and promoted osteogenic activity

Developing titanium-based dental implants with both excellent antibacterial properties and good osseointegration is crucial for the success of the implant operation and the long-term durability of the implant. In this study, a polydopamine-based coating was created by attaching TiO2 nanosheets-cyanine composites onto the titanium surface, enabling the integration of effective photothermal antibacterial therapy with osseointegration. The exceptional dual-photothermal conversion abilities of polydopamine and cyanine in the coating resulted in outstanding photothermal antibacterial and antibiofilm therapy against four types of bacteria. Furthermore, TiO2 nanosheets promoted the adhesion, proliferation and early osteogenic differentiation of osteoblasts. In an infected dental implant model in rats, the developed coating exhibited potent antibacterial activity and remarkable osteogenic differentiation in the bone, leading to increased bone formation around the implants. This innovative approach, combining photothermal therapy with osteogenic two-dimensional nanomaterials, presents a novel method for surface functionalization of implants to achieve effective antibacterial and osseointegration capabilities.

A biodegradable bi‐layer nano fibrous membrane fabricated by centrifugal spinning for active food packaging

AbstractTo solve the problem of cytotoxicity for most antimicrobial agents loaded in packaging materials, we developed a novel bi‐layer fibrous membrane by using centrifugal spinning, which of the outer layer was submicron native potato starch/polyvinyl alcohol (ST/PVA) composite fibers loaded with ZnO nanoparticles (ZnO NPs) for providing high antibacterial activity. The inner layer was nano‐based calcium alginate/polyethylene oxide (CA/PEO) fiber for providing excellent biocompatibility. The addition of ZnO caused the semicrystalline structures of ST/PVA fibers, while the CA/PEO fibers were shown semicrystalline structures due to the PEO. Fourier transform infrared indicated that posttreatment had not effect on the structures of ST/PVA/ZnO fiber, but the structure of CA/PEO fibers were affected by interaction between COO groups of alginate and Ca2+ ions. The results of mechanical property demonstrated that CA/PEO fibers showed highest stress of 3.83 ± 0.25 MPa and helpful for improving the stress of bi‐layer fibrous membrane. The obtained fibrous membrane had excellent antibacterial property with diameters of bacteriostatic zone against E. coli and S. aureus of 20.5 and 21.5 mm, respectively. On this basis, the shelf life of strawberry was improved up to 6th day by inhibit the growth of microorganisms, which indicated that the obtained fibrous membrane showed great potential for food packaging.