Superior Antibacterial Properties Research Articles

Enhanced effect of ultrasound and gelatin on physical and antibacterial properties of thymol/hollow mesoporous silicon spheres doped zein film

A new antibacterial film, Thy-HMSS/zein film, was prepared from hollow mesoporous silicon spheres loaded with thymol (Thy-HMSS) by ultrasonic optimization casting method (150 W power ultrasonic treatment solution for 3 min). To further enhance the film quality, a composite film, Thy-HMSS/Zein-gelatin film (Thy-HMSS/ZG film), was created by incorporating gelatin into zein. Compared to film containing the same amount of Thy, the effective protection and slow-release effect of HMSS on Thy resulted in a lower release rate of Thy in Thy-HMSS/zein films in the first 2 h, while the total amount of Thy released increased by 10 %. The appearance and structure of the films were optimized by ultrasonic treatment, which reduced the surface bubbles, cross section pores and particle agglomeration. The addition of gelatin enhanced the antibacterial effect of the film, the inhibition zone diameters of Escherichia coli and Staphylococcus aureus can be increased by up to 123.53 % and 159.37 %, respectively. Both Thy-HMSS/zein film and Thy-HMSS/ZG film showed no toxicity in cytotoxicity tests and exhibited good anti-corrosion ability when applied to blueberry preservation. Therefore, the combination of HMSS encapsulation with ultrasonic treatment and gelatin addition represents a suitable and straightforward approach for producing excellent antimicrobial films with superior appearance, structure, and antibacterial properties. This method holds significant potential in the food industry for producing sustainable active packaging materials while also offering new avenues for employing various techniques in films preparation.

Characteristics of novel Ti–40Nb-xCu alloy and surface treatment with superior antibacterial property and biocompatibility using micro-arc oxidation for dental implants

Peri-implantitis and insufficient osseointegration are the principal challenges faced by dental implants at present. In order to fabricate dual-function dental implant materials possessing both antibacterial and osteogenic capabilities, this study incorporates the antimicrobial element Cu into the Ti40Nb alloy, developing a novel Ti40Nb-xCu alloy with antibacterial properties. Among them, Ti40Nb3Cu has the best overall performance. Compared to Ti40Nb, the tensile strength increased by 27.97%, reaching 613 MPa. Although the elongation rate has decreased from 23% to 13.5%, the antibacterial rates against S. aureus and P. gingivalis both exceed 85%. Furthermore, the surface of Ti40Nb-xCu alloy was then treated with micro-arc oxidation to enhance its bioactivity, thereby accelerating osseointegration. The results indicated that the MAO treatment retains the antibacterial properties of the Ti40Nb3Cu alloy while significantly promoting bone formation through its introduced porous coating, thus heralding it as a propitious candidate material for dental implant applications.

Enhanced antibacterial and osteogenic properties of titanium by sputtering a nanostructured fluoride-doped tantalum oxide coating

Infections and poor osseointegration are the main challenges for titanium implants in clinical practice. Herein, we proposed fabricating a novel fluoride-doped tantalum oxide (F-TaOx) coating on titanium by one-step reactive sputtering deposition to endow implants with superior antibacterial and osteogenic ability. By altering the fluorine and oxygen loading amount, the coating’s physicochemical properties, corrosion resistance, antibacterial and osteogenic activities are tuned simultaneously. All coatings exhibit nano-morphology, superhydrophilicity and improved surface hardness. Despite containing fluoride, the F-TaOx coating produced with fluorine and oxygen dual-deposition still shows enhanced corrosion resistance due to the protection of existing metal oxidizes. The antibacterial test reveals that the F-TaOx coating exhibits long-lasting and superior antibacterial properties. The microenvironment acidification by F-, the excessive ROS generation and the disruption of ATP by F-, TiF3 and Ta2O5, and the repulsive force by superhydrophilic surface synergistically result in bacterial death. The cell experiments indicate that the F-TaOx coating shows good cytocompatibility, promote cell spread and osteogenic differentiation by enhancing ALP activities and ECM mineralization. This work provides a promising strategy for the surface functionalization of metallic implants to produce dual anti-infection and osteogenesis effects for orthopedic and dental applications.

Eco-friendly multifunctional coating for polyester-cotton blended fabrics with superior flame retardancy and antibacterial properties

Since the fire hazards of polyester-cotton blended (PTCO) fabrics and the hidden dangers of bacterial infection concerns caused by the contained cotton fiber, the design of flame retardant and antibacterial PTCO fabrics has received considerable attention. In this work, flame-retardant PTCO fabrics with satisfactory antibacterial properties were fabricated via a convenient and eco-friendly impregnation treatment involving guanidine phosphate (GP) and polyethylenimine (PEI). The prepared PTCO fabrics demonstrated excellent flame retardancy with a high limiting oxygen index value of 30.5 % and self-extinguishing capability, the damaged length was only 34 mm in the vertical flammability test. Furthermore, the peak heat release rate and the total heat release of coated PTCO fabrics were reduced significantly by 49 % and 38 %, respectively, indicating a substantial enhancement in fire safety. According to the analysis of the char residues and volatiles, GP presented great catalytic carbonization property, and PEI assisted the formation of the dense and stable carbon layer. The stable carbon layer effectively restricted mass and oxygen transfer between the PTCO fabrics and the environment. In addition, the introduction of PEI also produced more nonflammable gases to enhance the flame retardancy of the PTCO fabrics. Importantly, the GP/PEI coating barely deteriorate the physical and mechanical properties of the PTCO fabrics. The antibacterial rate of the GP/PEI-coated PTCO fabrics against Escherichia coli and Staphylococcus aureus was 99.99 %, similar to that of GP-coated fabrics, indicating the efficacy antibacterial properties of GP, and the addition of PEI did not compromise the antibacterial properties of GP. This work offers an efficient and simple approach to producing multifunctional PTCO fabrics with excellent flame retardancy and antibacterial properties, which are hopeful to expand the promising application of PTCO fabrics.

Fabrication and characterization of sodium alginate-silicon nitride-PVA composite biomaterials with damping properties

Silicon nitride is utilized clinically as a bioceramic for spinal fusion cages, owing to its high strength, osteoconductivity, and antibacterial effects. Nevertheless, silicon nitride exhibits suboptimal damping properties, a critical factor in mitigating traumatic bone injuries and fractures. In fact, there is a scarcity of spinal implants that simultaneously demonstrate proficient damping performance and support osteogenesis. In our study, we fabricated a novel sodium alginate-silicon nitride/poly(vinyl alcohol) (SA-SiN/PVA) composite scaffold, enabling enhanced energy absorption and rapid elastic recovery under quasi-static and impact loading scenarios. Furthermore, the study demonstrated that the incorporation of physical and chemical cross-linking significantly improved stiffness and recoverable energy dissipation. Concerning the interaction between cells and materials, our findings suggest that the addition of silicon nitride stimulated osteogenic differentiation while inhibiting Staphylococcus aureus growth. Collectively, the amalgamation of ceramics and tough hydrogels facilitates the development of advanced composites for spinal implants, manifesting superior damping, osteogenic potential, and antibacterial properties. This approach holds broader implications for applications in bone tissue engineering.

Antibacterial oxygen-sulfur terminal polymers from a facile initiator-strategy

Bacterial infection has become a long-term concern that seriously threatens human health. However, the application of conventional antibacterial materials in antibacterial treatment and infection prevention has been severely hindered due to their limitations such as complex synthesis, high cost, and high cytotoxicity. Therefore, developing a facile and cost-effective route to prepare high-performance antibacterial materials is of urgent need and significant importance. In this work, we for the first time reported that oxygen-sulfur terminal bonds possess excellent antibacterial properties, and the oxygen-sulfur terminal polymer (OSTP) can effectively kill bacteria when contacting and interacting with the bacteria. A universal and simple initiator strategy has been developed to fabricate OSTPs through a facile solution polymerization process. Via this approach, the PEGDA-APS OSTPs exhibited superfast and superior antibacterial properties against both Gram-positive and Gram-negative bacteria while maintaining good hemocompatibility and cytocompatibility, outperforming many common antibacterial agents that usually require several hours of bacterial extinction. Moreover, it was demonstrated that OSTPs exhibited excellent antibacterial activity in a wide range of application situations, including textile, medicine, washing, food, and coating, as well as antibacterial hydrogels.

An injectable chitosan-based hydrogel incorporating carbon dots with dual enzyme-mimic activities for synergistically treatment of bacteria infected wounds

Bacterial infections pose a serious threat to human health, and the emergence of superbugs and the growing antibiotic resistance phenomenon have made the development of novel antimicrobial products. In this paper, an ultrasmall Cu, N co-doped carbon dots (CDs-Cu-N) with excellent peroxidase mimic activity and enhanced catalase mimic activity was successfully prepared and anchored to an injectable chitosan (CS)-based hybrid hydrogel. As expected, the CDs-Cu-N-H2O2-CS hybrid hydrogel maintains the excellent enzyme-mimicking properties of CDs-Cu-N and shows superior antibacterial property, which has been proven to effectively promote the healing of S. aureus-infected wounds with good biocompatibility. Benefitting from the dual-enzyme-mimic activity of CDs-Cu-N, the hybrid hydrogel not only can catalyze the generation of highly toxic ROS from low concentration of H2O2 to inhibit the bacterial infections, but also can significantly promote the wound tissue repair and regeneration by improving the anoxic microenvironment and promoting neovascularization. In addition, this hybrid hydrogel also possessed excellent injectability and moldability. It can adapt to various the irregular shapes of acute wounds, maintaining a moist and safe microenvironment while prolonging the action time of nanozyme on wounds, thus promoting wound healing. This injectable hybrid hydrogel shows great potential applications in the field of wound infection management.

Effect of rare earth elements Ce and Yb on the in vitro properties of biodegradable Zn alloys

Biodegradable pure Zn and zinc alloys have received much attention in recent years, but the mechanical properties, corrosion behavior and biocompatibility of the previous reported pure zinc and zinc alloys do not fully meet the clinical requirements. Alloying and deformation technology are widely used in improving the properties of biodegradable pure Zn and zinc alloys. In this work, we have developed two new types of binary zinc alloys with the two rare earth elements (REE) cerium (Ce) and ytterbium (Yb). The effects of Ce and Yb on the microstructure, mechanical properties, corrosion behavior, in vitro biocompatibility of biodegradable Zn-xCe and Zn-xYb (x = 0.1, 0.2, 0.5, 1.0 wt %) were systematically investigated. The ultimate tensile strength, yield strength and elongation of Zn-xCe and Zn-xYb alloys are significantly improved compared with pure Zn. The Zn-xCe and Zn-xYb alloys have superior antibacterial properties The osteoblast MC3T3-E1 cells exhibited excellent cell activity with polygonal or fusiform extension and adhesion cultured in the series of Zn-xCe and Zn-xYb alloys’ extract solutions, indicating the good in vitro biocompatibility of Zn-xCe and Zn-xYb alloys. This work demonstrated that the Zn-xCe and Zn-xYb binary alloys have great potential as new biodegradable metals for future biomedical implants and devices.

Surface modification of the laser powder bed-fused Ti-Zr-Nb scaffolds by dynamic chemical etching and Ag nanoparticles decoration

Metallic lattice scaffolds are designed to mimic the architecture and mechanical properties of bone tissue and their surface compatibility is of primary importance. This study presents a novel surface modification protocol for metallic lattice scaffolds printed from a superelastic Ti-Zr-Nb alloy. This protocol consists of dynamic chemical etching (DCE) followed by silver nanoparticles (AgNP) decoration. DCE, using an 1HF + 3HNO3 + 12H2O23% based solution, was used to remove partially-fused particles from the surfaces of different as-built lattice structures (rhombic dodecahedron, sheet gyroid, and Voronoi polyhedra). Subsequently, an antibacterial coating was synthesized on the surface of the scaffolds by a controlled (20 min at a fixed volume flowrate of 500 mL/min) pumping of the functionalization solutions (NaBH4 (2 mg/mL) and AgNO3 (1 mg/mL)) through the porous structures. Following these treatments, the scaffolds' surfaces were found to be densely populated with Ag nanoparticles and their agglomerates, and manifested an excellent antibacterial effect (Ag ion release rate of 4–8 ppm) suppressing the growth of both E. coli and B. subtilis bacteria up to 99 %. The scaffold extracts showed no cytotoxicity and did not affect cell proliferation, indicating their safety for subsequent use as implants. A cytocompatibility assessment using MG-63 spheroids demonstrated good attachment, spreading, and active migration of cells on the scaffold surface (over 96 % of living cells), confirming their biotolerance. These findings suggest the promise of this surface modification approach for developing superelastic Ti-Zr-Nb scaffolds with superior antibacterial properties and biocompatibility, making them highly suitable for bone implant applications.

Ultra-small gold nanoparticles embedded cyclodextrin metal-organic framework composite membrane to achieve antibacterial and humidity-responsive functions

Cyclodextrin metal-organic framework (CD-MOF) is an edible and porous material that can serve as a template for synthesizing small-sized metal nanoparticles. However, its highly hydrophilic nature has limited its wider application. Herein, ultra-small gold nanoparticles (U-AuNPs) were loaded into CD-MOF to produce a composite material Au@CD-MOF. The CD-MOF was utilized as a template to control the size of the AuNPs. The synthesized Au@CD-MOF was easily dispersible in aqueous medium and its released U-AuNPs exhibited effective water dispersion stability within 120 days. Additionally, compared to gold nanoparticles prepared using traditional methods (T-AuNPs), the U-AuNPs exhibited superior antibacterial properties. Furthermore, hydrophilic Au@CD-MOF was incorporated into a hydrophobic polydimethylsiloxane (PDMS) matrix (Au@CD-MOF/PDMS) to achieve a humidity-responsive antibacterial function. The composite membrane exhibited remarkable responsiveness to humidity, showing almost no release of U-AuNPs at 0 % humidity. However, it exhibited approximately 89 % release within 1 h, and complete release of U-AuNPs was observed within 4 h under 100 % humidity. These findings highlight the successful preparation of a humidity-responsive antibacterial composite membrane, which has great potential applications in various scenarios, particularly in the field of antibacterial food packaging.

Biosynthesized copper oxide nanoparticles by Psidium guajava plants with antibacterial, antidiabetic, antioxidant, and photocatalytic capacity

AbstractWith an increasing focus on green technologies, this research aimed to synthesize copper oxide nanoparticles (CuO-NPs) using leaf extracts from Allahabad Safeda and Hisar Safeda for environmental and health protection. A range of concentrations of leaf extracts were employed in the synthesis of nanoparticles, utilizing 1–9% extract from Allahabad Safeda and 3–11% extract from Hisar Safeda. The synthesized CuO-NPs were characterized by UV–visible spectrophotometry, Dynamic light scattering, Fourier transform infrared spectroscopy, and Scanning electron microscope with energy-dispersive X-ray spectroscopy. CuO-NPs synthesized using 3% Allahabad Safeda extract and 5% Hisar Safeda extract exhibited a particle size of 15.88 nm and 14.05 nm, respectively. CuO-NPs synthesized with Allahabad Safeda extract exhibited superior antibacterial, antioxidant, antidiabetic, and photocatalytic properties. Their antibacterial tests demonstrated significant inhibition zones against Staphylococcus aureus (20.5 cm), Streptococcus latis (20.7 cm), Escherichia coli (19.5 cm), and Pseudomonas aeruginosa (19.7 mm). Additionally, CuO-NPs from Allahabad Safeda extract (70 µg/mL) exhibited 68.23% of scavenging activity against 2,2-diphenyl-1-picrylhydrazyl. Moreover, the same CuO-NPs at 100 µg/mL concentration showed 67.32% α-amylase inhibition and 75.18% α-glucosidase inhibition, confirming their antidiabetic activities. Furthermore, these nanoparticles demonstrated high performance in photocatalytic degradation, by degrading 82.31% methylene blue and 88.54% crystal violet within 150 min of UV irradiation. Overall, the findings highlight the feasibility of CuO-NPs synthesis using Allahabad Safeda extract and their potential applications in antibacterial treatment, combating diabetes, antioxidation, and environmentally friendly dye photodegradation process. Graphical Abstract

Formulation and evaluation of azithromycin-loaded silver nanoparticles for the treatment of infected wounds

Infected wounds pose a significant challenge in healthcare, requiring innovative therapeutic strategies. Therefore, there is a critical need for innovative pharmaceutical materials to improve wound healing and combat bacterial growth. This study examined the efficacy of azithromycin-loaded silver nanoparticles (AZM-AgNPs) in treating infected wounds. AgNPs synthesized using a green method with Quinoa seed extract were loaded with AZM. Characterization techniques, including X-ray Powder Diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Uv-Vis analysis were utilized. The agar diffusion assay and determination of the MIC were used to assess the initial antibacterial impact of the formulations on both MRSA and E. coli. In addition, the antimicrobial, wound-healing effects and histological changes following treatment with the AZM-AgNPs were assessed using an infected rat model. The nanoparticles had size of 24.9 ± 15.2 nm for AgNPs and 34.7 ± 9.7 nm for AZM-AgNPs. The Langmuir model accurately characterized the adsorption of AZM onto the AgNP surface, indicating a maximum loading capacity of 162.73 mg/g. AZM-AgNPs exhibited superior antibacterial properties in vivo and in vitro compared to controls. Using the agar diffusion technique, AZM-AgNPs showed enhanced zones of inhibition against E. coli and MRSA, which was coupled with decreased MIC levels. In addition, in vivo studies showed that AZM-AgNP treated rats had the best outcome characterized by improved healing process, lower bacterial counts and superior epithelialization, compared to the control group. In conclusion, AZM-AgNPs can be synthesized using a green method with Quinoa seed with successful loading of azithromycin onto silver nanoparticles. In vitro and in vivo studies suggest the promising use of AZM-AgNPs as an effective therapeutic agent for infected wounds.

TiO2–SiO2 nanocomposite via a novel sol-gel method with the addition of an energy monitoring device: Synthesized, characterization and anti-bacterial applications

The present paper successfully employs a modified sol-gel method to synthesize TiO2–SiO2 nanocomposites. By incorporating a hygrometer and energy monitoring devices, we achieved real-time monitoring of the drying process and optimized temperature control. Energy consumption during the drying process was observed, revealing that higher temperatures result in shorter drying times. The lowest energy consumption was recorded at 80 °C, while the optimal temperature, obtained from the conversion of the optimization diagram, occurred at 77 °C. Characterization was performed using different tools such as XRD, FT-IR analysis, XPS, FE-SEM-EDS, and HRTEM to determine the size and distribution of elements, crystal structure, and chemical bonds. Furthermore, an anti-bacterial test was conducted, revealing that the nanocomposite exhibited superior antibacterial properties against Staphylococcus aureus and Escherichia coli. Meeting the required standards, the TiO2–SiO2 nanocomposite produced by this method shows the potential to create a cleaner and more efficient environment in medical and industrial applications.

Preparation of modified halloysite nanotubes@Ag3PO4/polyacrylonitrile electrospinning membranes for highly efficient air filtration and disinfection

Particulate matters (PMs) and airborne bacteria are among the most severe indoor air issues due to their substantial implications for human health. Therefore, it was imperative to conduct a comprehensive investigation on air filtration materials with superior filtration performance and antibacterial properties. Here, the m-Hal@Ag3PO4 composite particles were prepared by using modified halloysite nanotubes (m-Hal) as the support of Ag3PO4 nano-photocatalysts. These composite antibacterial particles were uniformly dispersed within a polyacrylonitrile (PAN) solution and were subsequently electrospun into m-Hal@Ag3PO4/PAN composite nanofiber membranes (CNMs) possessing excellent antibacterial properties. The incorporation of 30 wt% m-Hal@Ag3PO4 additionally enhanced the filtration efficiency of PM0.3 to 99.9%, at an airflow rate of 32 L/min, while concurrently reducing the pressure drop by 36.7%. The photocatalytic degradation efficiency of CNMs towards ciprofloxacin reached 99%. The antibacterial experiments demonstrated that CNMs exhibited potent antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli)under dark and light conditions. Under visible light irradiation, the average diameter of the inhibition zone for the composite membrane surpassed that observed under dark conditions, indicating a predominant enhancement in its antibacterial efficacy through photocatalysis. The enhanced photocatalytic performance and excellent stability can be attributed to the incorporation of Ag3PO4 with m-Hal, which enhanced the dispersibility and facilitated efficient carrier separation of Ag3PO4. The present type of CNMs exhibited the advantages of high efficiency and low resistance air filtration, photodegradation ability, and recyclability, thereby enhancing the efficacy and lifespan of PMs filtration, bacteria disinfection, and antibiotic degradation. This offered a novel concept and viable approach for indoor air and water purification based on electrospinning technology.

Comparison of Organic Liquid Soap Made from Papaya-Turmeric and Aloe Vera-Piper Betel

<p>In the wake of the COVID-19 pandemic, the imperative to mitigate pathogen transmission has catalyzed the innovation of soaps imbued with antimicrobial and antibacterial properties. Diverging from conventional reliance on synthetic chemicals, often associated with adverse dermatological reactions, this study explores the formulation of organic liquid soaps. These soaps leverage naturally occurring antibacterial and antimicrobial compounds from readily accessible plants, presenting a viable alternative to commercially available inorganic body washes predominantly manufactured by small to medium-sized enterprises. Specifically, this research harnesses papaya and aloe vera extracts for their antimicrobial attributes, augmented with turmeric and piper betel for enhanced antibacterial efficacy. Despite the recognized potency of turmeric and piper betel, variability in their effectiveness necessitates rigorous validation against the Indonesian National Standards (SNI) to ensure product quality and safety. This includes comprehensive evaluations of pH levels, density, Total Plate Count (TPC), and Mold and Yeast Count (MYC) to certify the soap's inhibitory capacity against bacterial and fungal proliferation. Employing maceration and hot processing techniques, the formulated papaya-based soap adhered to SNI 4085:2017 criteria for pH and MYC, although initially failing the TPC test. Subsequent incorporation of turmeric extract facilitated compliance with all SNI benchmarks. Conversely, aloe vera formulations only satisfied pH requirements under the SNI, even after adding piper betel. However, substituting piper betel with turmeric extract enabled the aloe vera soap to fulfill the requisite SNI parameters. These findings underscore turmeric extract's superior antibacterial properties, positioning it as a pivotal component in papaya and aloe vera soap formulations. Contrary to prevalent assumptions regarding piper betel's antimicrobial and antibacterial effectiveness, our investigation substantiates turmeric's superior role in bacterial growth inhibition within organic soap matrices.</p>

Construction of copper-functionalized two-dimensional zeolitic imidazole framework-7 (ZIF-7) nanosheets for enhanced antibacterial and antibiofilm performance

Marine biological pollution restricts the sustainable development of marine economy. Cu2O stands as a predominant antifouling agent for developing marine resources engineering. However, the problems of easy aggregation, rapid failure, and explosive release of copper ions limit the practical application of Cu2O. In this work, a novel copper-functionalized two-dimensional zeolitic imidazolate framework-7 nanocomposites ZIF-7@Cu2O was successfully fabricated by in-situ growth methodology. The emergence of ZIF-7@Cu2O nanocomposites solves the above problems in the use of Cu2O. Due to the huge specific surface area of the 2D ZIF-7 nanosheets and the electrostatic interactions, the cubic Cu2O, with a diameter of 250 nm, can be uniformly and firmly anchored on the surface of 2D ZIF-7 nanosheets, thus effectively avoiding the rapid dissolution of cuprous oxide and reducing the release rate of copper ions. Antibacterial experiments demonstrate that, in comparison to ZIF-7, Cu2O, and ZIF-7/Cu2O (physical mixture of ZIF-7 and Cu2O), ZIF-7@Cu2O exhibits superior antibacterial properties with 99.99 % against E. coli and the minimum inhibitory concentration (MIC) of 32 μg/mL. Furthermore, the reactive oxygen species (ROS) assay confirms ZIF-7@Cu2O could promote the generation of ROS. Antibiofilm formation results reveal that ZIF-7@Cu2O nanocomposites are effective in preventing biofilm formation of E. coli and P. aeruginosa at a low concentration (50 μg/mL). Finally, ZIF-7@Cu2O nanocomposites are employed as fillers to prepare ZIF-7@Cu2O/EP composite coating, the bactericidal kinetics and bacterial adherence on the coating surface are investigated. We believe this work could provide novel insights into the rational design of 2D ZIF-based material in the field of antifouling.

Fabrication of silicon-based nickel nanoflower-encapsulated gelatin microspheres as an active antimicrobial carrier

Local antibiotic application might mitigate the burgeoning problem of rapid emergence of antibiotic resistance in pathogenic microbes. To accomplish this, delivery systems must be engineered. Hydrogels have a wide range of physicochemical properties and can mimic the extracellular matrix, rendering them promising materials for local antibacterial agent application. Here, we synthesized antibacterial silicon (Si)-based nickel (Ni) nanoflowers (Si@Ni) and encapsulated them in gelatin methacryloyl (GelMA) using microfluidic and photo-crosslink technology, constructing uniform micro-sized hydrogel spheres (Si@Ni-GelMA). Si@Ni and Si@Ni-GelMA were characterized using X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Injectable Si@Ni-GelMA exhibited excellent antibacterial activities owing to the antibiotic effect of Ni against Pseudomonas aeruginosa, Klebsiella pneumoniae, and methicillin-resistant Staphylococcus aureus, while showing negligible cytotoxicity. Therefore, the Si@Ni-GelMA system can be used as drug carriers owing to their injectability, visible light-mediated crosslinking, degradation, biosafety, and superior antibacterial properties.

Mussel-inspired superhydrophilic and antibacterial membranes for effective gravity-driven separation of oil-in-water emulsions

Substantial discharge of industrial oily wastewater calls for an efficient and sustainable treatment for resource recovery. Superwetting membranes offer a feasible approach to fractionate oil species and water from oily wastewater for addressing this technical challenge. In this study, we proposed a useful strategy for constructing a superhydrophilic membrane with superior antibacterial properties through rapid co-deposition of dopamine and 3-aminopropyltriethoxysilane (APTS) initiated by ammonium persulfate on the Cu nanoparticles-loaded porous PVDF substrate. The resultant superhydrophilic membrane yielded an underwater oil contact angle of 163.5°, enabling a fast and robust gravity-driven filtration for various oil-in-water emulsions with a separation efficiency of >99.9 %. Additionally, incorporating of Cu nanoparticles and polydopamine endowed the superhydrophilic membrane with superior antibacterial activity (100 % inhibition efficiency against Escherichia coli), and thereby remarkably enhancing the anti-biofouling performance. This study provides a viable approach to design high-performance membranes for separation of oil-in-water emulsions, with promising applications in the industrial and environmental sectors.

Creation of Wood-Based Hierarchical Superstructures via In Situ Growth of ZIF-8 for Enhancing Mechanical Strength and Electromagnetic Shielding Performance.

Given the escalating prevalence of electromagnetic pollution, there is an urgent need for the development of high-performance electromagnetic interference (EMI) shielding materials. Herein, wood-based electromagnetic shielding materials have gained significant popularity due to their exceptional performance as building materials. In this study, a novel wood-based composite with electromagnetic shielding properties is developed. Through the in situ growth of zeolitic imidazolate framework-8 (ZIF-8) crystals on wood fibers, coupled with uniform integration of carbon nanotubes (CNTs), a multifunctional composite named ZIF-8/Poplar-CNT composite is synthesized via a one-step thermoforming process. The incorporation of CNTs endows the composites with excellent EMI shielding effectiveness (EMI SE). Among these elements, despite ZIF-8 crystals not possessing intrinsic electromagnetic shielding functionality, their distinctive dodecahedral structure proves adept at scattering and reflecting electromagnetic waves within the composites, further improving the electromagnetic shielding effect. Hence, the ZIF-8/Poplar-CNT composite (56.95dB) has ≈10dB higher EMI SE compared to that of the composites without ZIF-8 crystals. Meanwhile, ZIF-8 crystals endow the materials with excellent tensile strength (54.84MPa, enhanced by 4 times). Moreover, the introduction of Zn2+ provides superior antibacterial properties. The potential applications of ZIF-8/Poplar-CNT composites extend to diverse areas such as building decoration, electronic products, and medical equipment.

In-Vitro and In-Silico Analysis of Antimicrobial Efficacy in Annona Muricata Leaf Extracts

Annona muricata and Annona reticulata, known for their traditional medicinal uses and antimicrobial properties, were investigated for their potential antibacterial effects. Extracts from fresh leaves were tested for antimicrobial activity, revealing that Annona muricata exhibited superior antibacterial properties compared to Annona reticulata, especially against E. coli strains. In silico analysis focused on 46 phytochemicals extracted from Annona muricata, which were docked with key bacterial proteins, including Gyrase, the 30S and 50S ribosomal subunits, Topoisomerase IV, and penicillin-binding protein. Notably, phytochemicals such as Quercetin 3–O-rutinoside (Rutin), Quercetin 3-O-neohesperidoside, Quercetin 3-O-glucoside (Isoquercetin), Luteolin 3´7-di-O-glucoside, and Homoorientin demonstrated strong docking scores and confidence score, indicating potential interactions that could lead to bacterial destruction. These findings suggest that certain phytochemicals of Annona muricata is a promising candidate for antibiotic development, opening avenues for further exploration in combating bacterial infections.