Search

Conventional oil-water separation membranes are difficult to establish a trade-off between membrane flux and separation efficiency, and often result in serious secondary contamination due to their fouling issue and non-degradability. Herein, a double drying strategy was introduced through a combination of oven-drying and freeze-drying to create a super-wettable and eco-friendly oil-water separating aerogel membrane (TMA df ). Due to the regular nacre-like structures developed in the drying process and the pores formed by freeze-drying, TMA df aerogel membrane finally develops regularly arranged porous structures. In addition, the aerogel membrane possesses excellent underwater superoleophobicity with a contact angle above 168° and antifouling properties. TMA df aerogel membrane can effectively separate different kinds of oil-water mixtures and highly emulsified oil-water dispersions under gravity alone, achieving exceptionally high flux (3693 L·m -2 ·h -1 ) and efficiency (99 %), while being recyclable. The aerogel membrane also displays stability and universality, making it effective in removing oil droplets from water in corrosive environments such as acids, salts and alkalis. Furthermore, TMA df aerogel membrane shows long-lasting antibacterial properties (photothermal sterilization up to 6 times) and biodegradability (completely degraded after 50 days in soil). This study presents new ideas and insights for the fabrication of multifunctional membranes for oil-water separation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Improving electron transfer rate of Co species and inhibiting aggregation of metal-organic frameworks (MOFs) particles are essential prerequisites for activating advanced oxidation process in wastewater treatment field. Here, we exploit Cu species with variable valence states to accelerate electron transfer of Co species and then to boost the unsatisfactory degradation efficiency for refractory pharmaceuticals via in-situ growth of copper and cobalt species on l-lysine functionalized carboxylated cellulose nanofibers. Utilizing the synergistic interplay of Co sites and deliberately exposed Cu 0 /Cu 1+ atoms, the subtly designed catalyst exhibited a surprising degradation efficiency (~100 %) toward tetracycline hydrochloride within 10 min (corresponding to a catalytic capacity of 267.71 mg/g) without adjusting temperature and pH. Meanwhile, the catalyst displays good recyclability, well tolerance for coexisting ions and excellent antibacterial performance derived from the intrinsic antibacterial property of Cu-MOF. This research provided a novel strategy to construct MOFs-cellulose materials toward degrading various stubborn antibiotic pollutants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This research presents a new approach to facilely fabricating a multifunctional film using polyvinyl alcohol (PVA) as the base material. The film is modified chemically to incorporate various desirable properties such as high transparency, UV-shielding, antibacterial activity, and fluorescence. The fabrication process of this film is straightforward and efficient. The modified film showed exceptional UV-blocking capability, effectively blocking 100% of UV radiation. It also exhibits strong antibacterial properties. Additionally, the film emitted bright blue fluorescence, which can be useful in various optical and sensing applications. Despite the chemical modification, the film retained the excellent properties of PVA, including high transparency (90%) at 550 nm and good mechanical strength. Furthermore, it demonstrated remarkable stability even under harsh conditions such as exposure to long-term UV radiation, extreme temperatures (-40 or 120 °C), or immersion in different solvents. Overall, this work showcases a promising strategy to develop versatile, structurally stable, transparent, and flexible polymer films with multiple functionalities. These films have potential applications in various fields that require protection, such as packaging materials, biomedical devices, and optical components., (© 2024 Wiley‐VCH GmbH.)

Solar desalination is an effective solution to address the global water scarcity issue. However, biofouling poses a significant challenge for solar evaporators due to the presence of bacteria in seawater. In this study, an anti-biofouling evaporator was constructed using the synergistic antibacterial effect of lignin and silver nanoparticles (AgNPs). The AgNPs were easily synthesized using lignin as reductant under mild reaction conditions. Subsequently, the Lignin-AgNPs solution was integrated into polyacrylamide hydrogel (PAAm) without any purification steps, resulting in the formation of Lignin/AgNPs-PAAm (LAg-PAAm). Under the combined action of AgNPs and the hydroquinone groups present in oxidized lignin, LAg-PAAm achieved over 99 % disinfection efficiency within 1 h, effectively preventing biofilm formation in pore channels of solar evaporators. The anti-biofouling solar evaporator demonstrated an evaporation rate of 1.85 kg m -2  h -1 under 1 sun irradiation, and maintained stable performance for >30 days due to its high efficient bactericidal effect. Furthermore, it also exhibited exceptional salt-rejection capability attributed to its superior hydrophilicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Treatment of infected wound by simultaneously eliminating bacteria and inducing angiogenesis to promote wound tissue regeneration remains a clinical challenge. Dynamic and reversable hydrogels can adapt to irregular wound beds, which have raised great attention as wound dressings. Herein, a sprayable chitosan-based hydrogel (HPC/CCS/ODex-IGF1) was developed using hydroxypropyl chitosan (HPC), caffeic acid functionalized chitosan (CCS), oxidized dextran (ODex) to crosslink through the dynamic imine bond, which was pH-responsive to the acidic microenvironment and could controllably release insulin growth factor-1 (IGF1). The HPC/CCS/ODex-IGF1 hydrogels not only showed self-healing, self-adaptable and sprayable properties, but also exhibited excellent antibacterial ability, antioxidant property, low-cytotoxicity and angiogenetic activity. In vivo experiments demonstrated that hydrogels promoted tissue regeneration and healing of bacteria-infected wound with a rate of approximately 98.4 % on day 11 by eliminating bacteria, reducing inflammatory and facilitating angiogenesis, demonstrating its great potential for wound dressing., Competing Interests: Declaration of competing interest The author declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in the paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The purpose of this study was to enhance the antimicrobial activity of bagasse paper by coating the paper with bismuth oxide (Bi 2 O 3 ) and using it to accelerate the process of wound healing. Paper sheets were prepared from sugarcane waste (bagasse). First, the paper sheets were coated with different Bi 2 O 3 concentrations to improve the antimicrobial activity of the paper. After that, the paper sheets were allowed to dry in an oven at 50 °C for 3 h. Then, in vitro antimicrobial activity was evaluated against different microbial species, including Gram-negative bacteria (i.e., Klebsiella pneumonia, Escherichia coli) and Gram-positive bacteria (i.e., Staphylococcus aureus, Streptococcus pyogenes). The obtained results showed that the paper coated with 25% and 100% Bi 2 O 3 had activity against all models of bacteria; however, the paper coated with 100% Bi 2 O 3 composite had the strongest inhibitory effect. Then, bagasse paper was coated with 100% Bi 2 O 3 and different antibiotics, to investigate their wound-healing potency in a wounded rat model for 14 days. Moreover, the paper coated with 100% Bi 2 O 3 inhibited the cellular migration in vitro. Conclusively, coating paper with Bi 2 O 3 enhances the wound-healing potential when applied to wounds. This impact could be ascribed to Bi 2 O 3 's broad antibacterial activity, which reduced infection and accelerated the healing process.

Sustainable organohydrogel electronics have shown promise in resolving the electronic waste (e-waste) evoked by traditional chemical cross-linking hydrogels. Herein, thermoplastic-recycled gelatin/oxidized starch (OST)/glycerol/ZnCl 2 organohydrogels (GOGZs) were fabricated by introducing the anionic polyelectrolyte OST and solvent exchange strategy to construct noncovalently cross-linking networks. Benefiting from the electrostatic interaction and hydrogen and coordination bonds, GOGZ possessed triple-supramolecular interactions and a continuous ion transport pathway, which resulted in excellent thermoplasticity and high ionic conductivities and mechanical and antibacterial properties. Because of the thermally induced phase transition of gelatin, GOGZ exhibited isotropic-ionic conductivity with a positive temperature coefficient and realized intrinsic affinity with the activated carbon electrode for fabricating a double-layer structure supercapacitor. These novel features significantly decreased the impedance (3.71 Ω) and facilitated the flexible supercapacitors to achieve thermoenhanced performance with 4.89 Wh kg -1 energy density and 49.2 F g -1 specific mass capacitance at 65 °C. Fantastically, the GOGZ-based stress sensor exhibited a monolinear gauge factor ( R 2 = 0.999) at its full-range strain (0 to 350%), and its sensitivity increased with the thermoplastic-recycled times. Consequently, this sustainable and temperature-sensitive sensor (-40 to 60 °C) could serve as health monitoring wearable devices with excellent reliability ( R 2 = 0.999) at tiny strain. Moreover, GOGZ could achieve efficient self-enhancement by stretch-induced alignment. The sustained weighted load, tensile strength, and elongation at break of the stretch-induced GOGZ were 6 kg/g, 2.37 MPa, and 300%, respectively. This self-enhanced feature indicated that GOGZ can be utilized as an artificial muscle. Eventually, GOGZ obtained high intrinsic antibiosis ( D inhibition circle > 25 mm) by a binding species (-COO - NH 3 + -) from COOH in OST and NH 2 in gelatin, freezing resistance, and water retention. In summary, this study provided an effective strategy to fabricate thermoplastic-recycled organohydrogels for multifunctional sustainable electronics with novel performance.

Bio-inspired borate cross-linked pulp foam (PF) with high porosity and low density can be widely used in many fields. However, PF is flammable, and lack of mechanical strength and antibacterial activity. To solve these issues, an ultra-strong PF was prepared by incorporation of chitosan and cationic polyacrylamide (CPAM). Results showed that the obtained PF exhibited highly improved mechanical properties (the compressive strength (485 kPa at a strain of 50%) was over 6 times higher compared with the borate cross-linked PF without chitosan and CPAM, and it was even higher than most of the reported cellulose-based porous materials). Also, the prepared PF has good performance on fire-retardance (hard to light), thermal insulation, antibiosis and sound absorption, due to the synergistic actions of borate, chitosan and CPAM. Additionally, spent liquor in preparing PF could be fully recycled, and thus this sustainable approach has potential for large-scale production of high-performance PF., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The conjugation between drug and biopolymers through an easily hydrolysable bond such as ester linkage, disulfide linkage, or imine-bond have been extensively employed to control the drug release pattern and improve its bioavailability. This work described the conjugation of 9-aminoacridine (9-AA) to Gum Arabic (GA) via Schiff's base, as a pH-responsive bond. First, GA was oxidized to Arabic Gum dialdehyde (AGDA), then a different amount of 9-AA (10, 25, and 50 mg 9-AA) was coupled to defined amount of AGDA, the coupling was confirmed by elemental analysis and different spectroscopic tools. In addition, the physical features of Schiff's base conjugates including surface morphology, thermal stability, and crystalline structure were examined. The thermogravimetric analysis revealed that the incorporation of 9-AA slightly improved the thermal stability. The coupling of 9-AA to AGDA dramatically enhanced its in vitro antimicrobial and antitumor activities. All conjugates exhibited broad-spectrum activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, and Candida albicans. Moreover, AGA 25 and AGA 50 demonstrated promising capability to suppress the proliferation of human colon cancer cell line (Caco-2), with IC 50 190.10 and 180.80 μg/mL respectively., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Bacterial infectious diseases are serious health problem which extends to economic and social complications. Moreover, bacterial antibiotic resistance, lack of suitable vaccine or emergence of new mutations is forcing the development of novel antimicrobial agents. The objective of this study is to synthesize and characterize star-like zinc oxide nanoparticles for the application of antibacterial activities in cellulose based hygiene products. ZnO NPs were in situ synthesized via precipitation method on the surface of cellulose fibers. Since bactericidal activity of nanoparticles in part depends on the concentration in the growth medium, various amount of ZnO was incorporated into cellulose matrix ranging from 1 to 3 wt%. Microscopic (TEM, SEM) and spectroscopic (FT-IR, XRD) methods were utilized to investigate the final products. The infrared absorption spectra analysis supported by theoretical finding that during the reaction, ZnO nanoparticles could be bonded with cellulose fibers via hydrogen bonding. The yield of functionalization was determined through thermogravimetric analysis. Collected data proved the successful functionalization of the cellulose fibers with nanoparticles. Static contact angle measurements were carried out showing absorptive character of as prepared fabrics. All the samples were tested for the antibacterial properties and the results were compared to the samples prepared from the pristine cellulose fibers. Moreover, mechanical tests were performed revealing that the addition of only 2 wt% of the nanofiller boosted tensile, tearing and bursting strength by a factor of 1.6, 1.4 and 2.2 in comparison to unfunctionalized paper sample, respectively. Fabricated fabric presenting high hydrophilicity and antibacterial properties have gained increased applications in fabric industry, including hygiene product industry and hence the result of this study would be a welcomed option., (© 2022. The Author(s).)

In the experiment, a chemical oxidation method was used to prepare nano-divalent silver oxide powder with a particle size of about 10 nm. Compared with silver nanoparticles and monovalent silver compounds, nano‑silver oxide has better antibacterial properties. The cellulose antibacterial aerogel was prepared by combining it with cellulose nanofibrils and using freeze-thaw cycles and freeze-drying methods. The microscopic morphology, mechanical properties, in vitro release of silver ions, antibacterial properties and biodegradability of composite aerogels were studied. The porosity of the cellulose antibacterial aerogel can reach 94%, the swelling rate was greater than 1000%, and the pore size was between 13 and 15 nm, which showed a larger storage space and attachment site for the aerogel. The diameter of the inhibition zone of the aerogel against Escherichia coli and Staphylococcus aureus was 23 mm and 20 mm respectively, and the aerogels still exhibited significant antibacterial activities with more than 99.5% reductions in Escherichia coli and Staphylococcus aureus, which shows highly effective antibacterial properties. This research proposes an economical and novel preparation method of antibacterial cellulose aerogel, making it a candidate material with high efficiency, broad-spectrum antibacterial and more suitable for life needs., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Hydrogel dressings with similar structural characteristics to the extracellular matrix and tunable physicochemical properties have become promising candidates for wound healing. However, the fabrication of an ideal hydrogel dressing with low-cost, good biocompatibility, excellent hemostatic capacity, potent and broad-spectrum antibacterial activity remains a huge challenge. Herein, a lignocellulose-based nanocomposite hydrogel (ATC/SA/PVA) is fabricated by simply mixing Ag nanoparticles loaded, tannic acid-decorated lignocellulose nanofibrils with sodium alginate and polyvinyl alcohol. Based on the dynamic borate ester bonds and multiple weak hydrogen bonds, the fabricated hydrogel exhibits excellent flexibility and self-healing performance. Its highly porous structure endows the gel excellent blood and tissue exudates absorption ability. Interestingly, the release behavior of Ag nanoparticles from hydrogel displays pH dependence, which can facilitate the accumulation of Ag nanoparticles at the wound site, thereby accelerating the process of wound healing. In vitro antibacterial assay demonstrates the potent antibacterial ability of hydrogel against both Gram-positive (S. aureus) and negative bacteria (E. coli). More importantly, in vivo investigations reveal that such hydrogel can effectively accelerate tissue regeneration and wound healing with no obvious adverse effects. All these results suggest that this nanocomposite hydrogel would be a promising candidate to accelerate wound healing., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A lignin-based PU coating was prepared for paper-based green packaging. Two representative diisocyanate were used to prepare the coatings. Due to the rigid aromatic, the physical properties of the TDI system reached the maximum below the lignin content of 40%. The HDI that contains flexible aliphatic chains alleviated the brittleness of coating, and it showed physical advantages when the lignin content was more than 50%. Owing to the high lignin content, the coating presented enhanced thermal stability. After coated with the lignin-based PU coatings, the dry tensile strength of coated paper was improved by 126%. Amazingly, the wet strength was increased from 0.31 to 12.6 MPa with an improvement nearly 40 times. Based on the coordination of lignin, Ag + was introduced into the PU matrix, which imparted the coating with excellent antibacterial ability. The colony forming units of E. coli and S. aureus were both less than 1. However, no inhibition halo was observed, which indicated that the Ag was firmly anchored on the coating and the antibacterial ability is only available when the bacterial contact the coating surface. The lignin-based PU coating with favorable sustainability and properties shows great potential in paper-based green packaging fields., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This work demonstrated a facile and sustainable approach to functionalize cellulose nanopaper (CNP) by impregnation of chitosan (CS) and the followed halogenation. It was found that the tensile strength of the functionalized CNP (CNP/CS-Cl) was enhanced by 38.3% and 512.6% at dry and wet conditions, respectively. Meanwhile, the total transmittance (at 550 nm) of CNP/CS-Cl was increased from 75% of pure CNP to 85%, with 35% decrease in optical haze. Moreover, the CNP/CS-Cl exhibited significant enhancement in barrier properties. Importantly, part of the amino groups on CS were transformed into N-halamines during the halogenation process, which endowed the CNP/CS-Cl with excellent antibacterial performance against both S. aureus and E. coli with 100% bacterial reduction after 10 min of contact. Thus, this work provides a simple and efficient approach to functionalize CNP with water resistance, high transparency, excellent antibacterial and barrier properties, which will expand the potential applications of CNP., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Pectin is widely used in food and pharmaceutical industries. However, due to its polysaccharide nature it lacks antimicrobial activity. In the current work, new pectin derivatives with interesting optical and antimicrobial properties were prepared via supramolecular chemistry utilizing Fe- or Cu-terpyridine (Tpy-Fe and Tpy-Cu) motifs. To proof derivatization of pectin, ultraviolet-visible spectroscopy (UV-Vis) and Fourier Transform infrared (FTIR) were used. In addition, the prepared pectin derivatives retained the known emulsification activity of the non-modified sugar beet pectin as seen from the particle size analysis of oil-in-water emulsions. The prepared derivatives showed antibacterial activity toward selected Gram-positive and Gram-negative bacteria. In addition, cytotoxicity test showed that the Tpy-Fe-pectin derivative was non-toxic to cells of human hepatocarcinoma, breast adenocarcinoma MCF7, and colorectal carcinoma cells at concentrations up to 100 μg/ml, while Tpy-Cu-pectin had moderate toxicity toward the aforementioned cells at the same concentration levels. The prepared derivatives could have potential applications in emulsions with antibacterial activity., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A low-cost and portable paper-based analytical device has been developed for high throughput and on-site monitoring TC residue in milk through visualized colorimetric reaction. The filtration and concentration effect induced by the porous nature of paper contribute to strengthen the color intensity, leading to quantitative and sensitive detection of tetracycline reaching 1 ppm detection limit, with the linear range of 1-100 ppm both in water and milk samples. The applicability was demonstrated by detection of TC in 18 different types of real milk samples with good recovery ranging from 88% to 113%. Furthermore, the dynamic degradation behavior of tetracycline was monitored through the device. To the best of our knowledge, this is the first report of colorimetric detection of tetracycline in milk using the paper-based device. This simple, fast, cost-effective (~$0.50 per device) and equipment-free paper-based platform provides a promising tool for future application in food and environmental safety., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The laccase/TEMPO system was employed to oxidise the C6 primary hydroxyl group on the chitosan (CS) to form a carboxyl group to obtain oxidised chitosan (C-COS). The silver-oxidised chitosan complex(C-COS-Ag) was prepared by reacting C-COS with silver nitrate, then C-COS-Ag and cotton fibres were subjected to a reaction to prepare bacteriostatic fibres. FT-IR and XPS analysis showed that: Ag + and C-COS were combined in these forms: Ag, [Ag(NH 3 ) 2 ] OH, -COOAg, and Ag 2 O. C-COS-Ag was combined with cotton fibres by way of ester bonds. The inhibition zone of bacteriostatic fibres was all greater than 11 mm. After 50 washing tests, the bacteriostatic effect of bacteriostatic fibres remained at above 99 %. The amount of silver ions that had migrated from the bacteriostatic fibre was 3.336 mg/kg., (Copyright © 2021. Published by Elsevier Ltd.)

The development of new antimicrobial strategies that act more efficiently than traditional antibiotics is becoming a necessity to combat multidrug-resistant pathogens. Here we report the efficacy of laser-light-irradiated 5,10,15,20-tetrakis( m -hydroxyphenyl)porphyrin ( m THPP) loaded onto an ethylcellulose (EC)/chitosan (Chs) nanocomposite in eradicating multi-drug resistant Pseudomonas aeruginosa , Staphylococcus aureus , and Candida albicans. Surface loading of the ethylcelllose/chitosan composite with m THPP was carried out and the resulting nanocomposite was fully characterized. The results indicate that the prepared nanocomposite incorporates m THPP inside, and that the composite acquired an overall positive charge. The incorporation of m THPP into the nanocomposite enhanced the photo- and thermal stability. Different laser wavelengths (458; 476; 488; 515; 635 nm), powers (5-70 mW), and exposure times (15-45 min) were investigated in the antimicrobial photodynamic therapy (aPDT) experiments, with the best inhibition observed using 635 nm with the m THPP EC/Chs nanocomposite for C. albicans (59 ± 0.21%), P. aeruginosa (71.7 ± 1.72%), and S. aureus (74.2 ± 1.26%) with illumination of only 15 min. Utilization of higher doses (70 mW) for longer periods achieved more eradication of microbial growth.

Cushioning and antibacterial packaging are the requirements of the storage and transportation of fruits and vegetables, which are essential for reducing the irreversible quality loss during the process. Herein, the composite of carboxymethyl nanocellulose, glycerin, and acrylamide derivatives acted as the shell and chitosan/AgNPs were immobilized in the core by using coaxial 3D-printing technology. Thus, the 3D-printed cushioning-antibacterial dual-function packaging aerogel with a shell-core structure (CNGA/C-AgNPs) was obtained. The CNGA/C-AgNPs packaging aerogel had good cushioning and resilience performance, and the average compression resilience rate was more than 90%. Although AgNPs was slowly released, CNGA/C-AgNPs packaging aerogel had an obvious antibacterial effect on E. coli and S. aureus . Moreover, the CNGA/C-AgNPs packaging aerogel was biodegradable. Due to the customization capabilities of 3D-printing technology, the prepared packaging aerogel can be adapted to more application scenarios by accurately designing and regulating the microstructure of aerogels, which provides a new idea for the development of food intelligent packaging.

Bacterial breeding is the main cause of food perishability, which is harmful to human health. Silver nanoparticles (AgNPs) are one of the most widely used antimicrobial agents, but they are easy to release and cause cumulative toxicity. In this work, with corn stalk as green reductant and GO as template, a simple electrostatic self-assembled sandwich-like chitosan (CS) wrapped rGO@AgNPs nanocomposite film (CS/rGO@AgNPs) was synthesized to achieve stabilizing and controlled-release of AgNPs. The results showed that the the CS/rGO@AgNPs film continued releasing AgNPs for up to 14 days, and the final release amount of silver nanoparticles was only about 1.9 %. More importantly, the nanocomposite film showed durable antibacterial effect and good antibacterial activity against E. coli and S. aureus, and they showed no toxicity to cells. Hence, the nanocomposite film has potential application as an effective and safe packaging material to prolong the shelf life of food products., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A novel core/shell C-TiO 2 /CoTiO 3 type II heterojunction was successfully synthesized via a direct calcination method by using MIL-125/Co core-shell nanocakes as a sacrificial template and precursor. In the calcination process, the organic ligand in MIL-125 acts as an in-situ carbon doping source to form a carbon-doped TiO 2 core (C-TiO 2 ). At the same time, CoTiO 3 nanoparticles are formed on the surface of C-TiO 2 by an in-situ solid-state reaction between the C-TiO 2 and Co 2+ shell of MIL-125/Co. Due to such delicate core/shell structural features, carbon doping and type II heterojunctions, C-TiO 2 /CoTiO 3 core/shell composites can effectively harvest visible light, facilitate the interfacial separation and suppress the recombination of photogenerated electron-hole pairs, leading to the remarkable photocatalytic activity for removal of ciprofloxacin (CIP). In particular, C-TiO 2 /CoTiO 3 -3 exhibits the best photocatalytic degradation activity of CIP with a degradation efficiency of 99.6% and a total carbon content removal percentage of 76% under visible-light illumination for 120 min. In addition, the proposed photocatalytic mechanism study illustrated that the main radical species in the photocatalytic degradation of CIP using C-TiO 2 /CoTiO 3 as the photocatalyst is •OH. This work provides a new approach and insight for synthesizing core/shell heterojunction-based photocatalysts for various applications., (Copyright © 2020. Published by Elsevier B.V.)

The asymmetric wetting membranes have attracted intense attention in liquid directional transportation. However, it is a huge challenge to prepare surface layer membrane for sanitary products with antibacterial and asymmetric wettability by a simple method. Herein, the bacterial cellulose grafted with chitosan (BC-CS) was used as the hydrophilic agent to modify polypropylene nonwoven fabric (PPF) substrate via easy and effective one-sided layer-by-layer spraying to prepare the asymmetric wetting and antibacterial composite membrane (BC-CS/PPF). It showed that the BC-CS/PPF had good physical properties, which was attributed to the strong and uniform physical combination between nano-sized BC-CS and PPF. The sanitary products with BC-CS/PPF surface layer, denoted as BC-CS/PPF sanitary products, also had good absorption and anti-return property. The antibacterial test revealed that BC-CS had an excellent performance against S. aureus and E. coli in the simulated application environment. Moreover, the antibacterial performance was better than that of commercial sanitary products., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This work is strategically premeditated to study the potential of a herbal medicinal product as a natural bioactive ingredient to generate nanocellulose-based antibacterial architectures. In situ fibrillation of purified cellulose was done in cinnamon extract ( ci E) to obtain microfibrillated cellulose (MFC). To this MFC suspension, carboxylated cellulose nanocrystals (cCNCs) were homogeneously mixed and the viscous gel thus obtained was freeze-dried to obtain lightweight and flexible composite aerogel architectures impregnated with ci E, namely, ci MFC/cCNCs. At an optimal concentration of 0.3 wt % cCNCs (i.e., for ci MFC/cCNCs_0.3), an improvement of around 106% in compressive strength and 175% increment in modulus were achieved as compared to pristine MFC architecture. The efficient loading and interaction of ci E components, specifically cinnamaldehyde, with MFC and cCNCs resulted in developing competent antibacterial surfaces with dense and uniform microstructures. Excellent and long-term antimicrobial activity of the optimized architectures ( ci MFC/cCNCs_0.3) was confirmed through various antibacterial assays like the zone inhibition method, bacterial growth observation at OD 600 , minimum inhibitory concentration (MIC, here 1 mg/mL), minimum bactericidal concentration (MBC, here 3-5 mg/mL), and Live/Dead BacLight viability tests. The changes in the bacterial morphology with a disrupted membrane were further confirmed through various imaging techniques like confocal laser scanning microscopy, FESEM, AFM, and 3D digital microscopy. The dry composite architecture showed the persuasive capability of suppressing the growth of airborne bacteria, which in combination with antibacterial efficiency in the wet state is considered as an imperative aspect for a material to act as the novel biomaterial. Furthermore, these architectures demonstrated excellent antibacterial performance under real "in use" contamination prone conditions. Hence, this work provides avenues for the application of crude natural extracts in developing novel forms of advanced functional biomaterials that can be used for assorted biological/healthcare applications such as wound care and antimicrobial filtering units.

Bio-based nanomaterials with antimicrobial functions hold promise in replacing petroleum-based packaging for food preservation. A nanocellulose-based hybrid film with antimicrobial properties was developed from sugarcane bagasse and nisin. Cellulose nanofibrils (CNFs) were prepared from sugarcane bagasse pulp by mechanical grinding, and mixed with nisin to prepare CNFs/nisin nanohybrid films. The concentration of nisin has a remarkable influence on the mechanical, light transmission, gas barrier, and antimicrobial properties of these films. CNFs/nisin hybrid films with 1920 mg/L nisin exhibit good light transmission, relatively high tensile strength, low oxygen permeability, and low water vapor transmission rates. This hybrid film was used as a liner of low-density polyethylene plastic packaging for ready-to-eat ham; it completely inhibited Listeria monocytogenes during 7 days of storage at 4 °C. Such novel CNFs/nisin nanohybrid films are expected to expand the application of bagasse nanocellulose in active packaging for food preservation., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, a carboxyl-modified cellulosic hydrogel was developed as the base material for wound dressings. ε-poly-l-lysine, a natural polyamide, was then covalently linked to the hydrogel through a bioconjugation reaction, which was confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR). The antibacterial efficacy of the hydrogel was tested against two model bacteria, Staphylococcus aureus and Pseudomonas aeruginosa , two of the most commonly found bacteria in wound infections. Bacterial viability and biofilm formation after exposure of bacteria to the hydrogels were used as efficacy indicators. Live/Dead assay was used to measure the number of compromised bacteria using a confocal laser scanning microscope. The results show that the antibacterial hydrogel was able to kill approximately 99% of the exposed bacteria after 3 h of exposure. In addition, NIH/3T3 fibroblasts were used to study the biocompatibility of the developed hydrogels. Water-soluble tetrazolium salt (WST)-1 assay was used to measure the metabolic activity of the cells and Live/Dead assay was used to measure the viability of the cells after 24, 48, and 72 h. The developed antibacterial hydrogels are light weight, have a high water-uptake capacity, and show high biocompatibility with the model mammalian cells, which make them a promising candidate to be used for wound dressing applications.

Silver nanoparticles (AgNPs) have been widely used for sterilization due to their broad-spectrum bactericidal properties. However, there exist the problems of premature releasing and accumulative toxicity when free AgNPs are applied. This study proposed a one-pot hydrothermal strategy to synthesize carbon spheres immobilized silver nanoparticles (AgNPs@CS). The synthesis involves with silver ammonia solution as Ag precursor, and corn stalk as green reducing agent and carbon precursor. Furthermore, AgNPs@CS was anchored by cellulose nanofibers (CNF) to obtain the antibacterial composite paper. The obtained CNF/AgNPs@CS paper exhibited superior antibacterial properties against E. coli and S. aureus. Notably, the accumulative release rate of AgNPs from AgNPs@CS was 10.2% in 9 days, while that from CNF/AgNPs@CS paper was only 6.7% due to the anchoring effect of both CS and CNF, which was low for avoiding the cumulative toxicity problem. In addition, the mechanical and barrier properties of CNF/AgNPs@CS paper were also improved by 29.4% (tensile index), 2.7% (tear index), 7.4% (burst index), 10% (folding endurance), 0.8% (water vapor transmission) and 9.4% (oxygen transmission rate), respectively. Therefore, the composite paper has potential application as a medical antibacterial material., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, hexagonal boron nitride nanosheets enriched with hydroxyl groups (h-BN-OH) were successfully grafted on the surface of cellulose fibers after the simple and effective exfoliation and oxidation of bulk h-BN. OH groups of h-BN-OH and the ones presented on the surface of cellulose fibers interacted via hydrogen bonding. Both spectroscopic (FT-IR, XRD) and microscopic (TEM, SEM, and atomic force microscopy (AFM)) methods results proved the successful functionalization of the cellulose fibers with the nanomaterial. Modified cellulose fibers were used to prepare paper sheets samples with different concentrations of the nanomaterial (1 wt %, 2 wt %, and 3 wt %). All the samples were tested for the antibacterial properties via the colony forming unit method and exhibited good performance against both Gram-negative ( E. coli) and Gram-positive ( S. epidermidis ) model bacteria. Additionally, the influence of the volume of working bacterial suspension on the antibacterial efficiency of the obtained materials was examined. The results showed significantly better antibacterial performance when the volume of bacterial suspension was reduced. Mechanical properties of the paper samples with and without nanofiller were also characterized. Tensile strength, tearing strength, and bursting strength of the paper samples containing only 2 wt % of the nanofiller were improved by 60%, 61%, and 118% in comparison to the control paper samples, respectively. Furthermore, the nanofiller improved the thermal properties of the composite paper-the heat release rate decreased by up to 11.6%. Therefore, the composite paper can be further explored in a wide range of antibacterial materials, such as packaging or paper coatings.

Cyanoethyl cellulose (CEC)/ magnetite (Fe 3 O 4 ) flexible composite film with enhanced dielectric and magnetic properties was successfully prepared. CEC has been synthesized from micro crystalline cellulose (MCC). The effects of magnetite mass fraction on the morphology, microstructure, thermal stability, and antimicrobial activity of the as-prepared composite films were investigated. The Vibrating sample magnetometer (VSM) and broadband dielectric spectrometer was also employed to study the magnetic and dielectric properties, respectively. In addition to study the computational calculation of MCC, and CEC by DFT/ B3LYP/6-31G (d) basis sets. The results showed that, the sample that is magnetite free has a diamagnetic response to the applied magnetic field, however the other samples that is loaded with magnetite show super-paramagnetic behavior indicating that the particles' sizes of the magnetite mostly below 20 nm. Also, antimicrobial activities of composite films against (G + ve), (G-ve), were investigated., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict to interests., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Wound bleeding and infection are two of the major threats to patients' lives, but developing safe materials with high hemostasis efficiency and antibacterial activity remains a major challenge. Silver nanoparticles (AgNPs) are suitable as antibacterial agents in the hemostatic process, but the application is hampered because of easy accumulation of toxicity. Herein, thiol-modified chitosan (TMC) was prepared by modifying with mercaptosuccinic acid and then was used to immobilize AgNPs to obtain composite sponges (TMC/AgNPs) for stemming the bleeding and preventing infection. TMC/AgNPs sponges had complex interlaced tubular porous structure with high porosity (99.42%), indicating high absorption. TMC had high immobilization efficiency for AgNPs-the release rate of AgNPs was 14.35% after 14 days-but the TMC/AgNPs sponge still had excellent antibacterial activity against Staphylococcus aureus , Escherichia coli , and Pseudomonas aeruginosa . In vitro and in vivo experiments confirm that the TMC/AgNPs sponge had fast and efficient hemostatic performance in comparison with the PVF sponge, and its possible mechanism was the synergistic effect of high blood absorption capacity and the interaction between amino, sulfydryl, and blood cells. Furthermore, the TMC/AgNPs sponge can promote wound healing by preventing wound infection, while the PVF sponge cannot. More importantly, the sponges had good safety due to the immobilization of TMC for AgNPs.

This study explores the modification of bacterial nanocellulose (BNC), produced in fermented tea medium with bio-extracts from herbal plants, to produce entirely natural antibacterial nanocellulose films. The antibacterial property was imparted by impregnating the synthesized BNC into bio-extracts of Terminalia arjuna (arjuna), Azadirachta indica (neem), Withania somnifera (ashwagandha), Tinospora cordifolia (giloy), and Murraya koenigii (curry leaves). FE-SEM analysis of modified BNC films revealed the presence of cloudy layer of bio-extracts over the BNC nanofibrous network. The modified BNC production was confirmed by ATR-FTIR. The modified BNC showed tremendous antibacterial activity against Escherichia coli (E. coli) and Aerococcus viridians (A. viridans). T. arjuna modified BNC showed the highest antibacterial activity against E. coli and A. viridans with inhibition zone of 27.08 mm and 26.34 mm, respectively, while M. koeniggi modified BNC showed the lowest antibacterial activity for both E. coli and A. viridans with inhibition zone of 14 mm and 14.2 mm, respectively. The water retention, moisture content and porosity values reflect highly hydrophilic nature of BNC films and their well suitability for varied biomedical applications like antibacterial wound dressings, herbal biomasks, scaffoldings, etc. The modification of BNC films with the bio-extracts used in this study has not been reported previously., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Cellulose-based materials are widely used in the biomedical field. However, the lack of antibacterial activities of cellulose fibers inevitably causes bacterial infection damages. In this study, Schiff base was first introduced to endow the cellulose fibers good antibacterial property and copper ions were complexed with Schiff base to form a complex. The prepared complex greatly enhanced the antibacterial properties of the cellulose fibers. FT-IR, XRD, UV-vis and SEM-EDS results proved the successful synthesis of Schiff base and its copper (II) complex. The antibacterial tests indicated that the width of the inhibition zone of the as-prepared cellulose-based Schiff base-Cu (II) complex against E. coli and S. aureus increased by 472 % and 823 %, respectively, in comparison to the Schiff base ligand. This significant increase could be attributed to the incorporation of the copper ions (II). This Schiff base-Cu (II) complex containing cellulose-based antibacterial materials are expected to be widely used for biomedical application., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this work, biodegradable cellulose-based biosorbents (MOFs/OCBs) with dual function of dye removal and microbial inactivation were fabricated by in situ anchoring metal-organic frameworks (MOFs) on the TEMPO oxidized corncobs (OCBs). Results showed that delignification and oxidation can develop the OCBs with more cellulose content, carboxyl groups and specific surface area, thus facilitating the deposition of MOFs. The porous and carbohydrate-rich OCBs can serve as supports and stabilizers for MOFs, allowing for enhanced stability and recyclability of MOFs powders. The MOFs, namely HKUST-1 and ZIF-8, can endow the OCBs multiple functions of good adsorption capacity to methyl orange (from 8% of OCBs to 55% of HKUST-1/OCBs and 84% of ZIF-8/OCBs) and excellent antibacterial activity (from 0 of OCBs to 90.2% of HKUST-1/OCBs and 44.8% of ZIF-8/OCBs). Such a concept may offer a new pathway for preparing economical and efficient biosorbents for environmental remedy purposes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Fast and accurate detection of S. aureus and effectively kill S. aureus in the bloodstream in low doses acted as key roles in medicine and microbiology studies. In this work, sufonated-hyaluronic acid (S-HA) terminated magnetic mesoporous silica nanoparticles (MMSNs) loaded with vancomycin was successfully prepared, and S. aureus antibody was further modified on the surface of MMSNs (Ab@S-HA@MMSNs) by amidation reaction. The result showed that Ab@S-HA@MMSNs were 240 nm-sized spheres with worm-like mesoporous channels. With the aid of magnetic interaction, Ab@S-HA@MMSNs were modified on the surface of magnetic glassy carbon electrode (MGCE). This prepared immunosensor exhibited an excellent detection limit and linear range, and possessed good selectivity, stability and reproducibility. Besides, since the S-HA terminated MMSNs have anticoagulant property, the Ab@S-HA@MMSNs/MGCE showed antiadhesion property, which ensure that it can be directly applied to detect the amount of S. aureus in whole blood. What's more, with an increasing amount of S. aureus arriving at MGCE, the capping Ab@S-HA@MMSNs were degraded by Hyal which was secreted by S. aureus, and the packaged vancomycin was subsequently released. Ultimately, S. aureus can be effectively killed. Therefore, this integrated platform would be a promising multifunctional platform for achieving accurate diagnosis and efficient treatment of S. aureus bloodstream infection., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The present study describes the impregnation of coffee extract (CE) into bacterial cellulose synthesized from kombucha tea fungus (KBC) of different cellulose content, incubated for different incubation periods (2, 4, and 10 days), to prepare biocomposites having the potential for wound healing applications. Total polyphenols in hydroalcoholic extracts from ground roasted coffee and its release from the prepared biocomposites were determined as gallic acid equivalent. The polyphenols content was found to be 13.66 mg/g and the minimum inhibitory concentration (MIC) of the CE was determined using colony-forming unit (CFU) method against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus where the growth inhibition was 86 and 97% respectively. Biocomposites (KBC/CE) with the lowest cellulose and CE content showed the highest wet tensile stress (3.35 MPa), absorption of pseudo extracellular fluid (154.32% ± 4.84), and water vapor transmission rate (3184.94 ± 198.07 g/m 2 /day), whereas it showed the lowest polyphenols' release (51.85% ± 2.94)when immersed in PBS buffer of pH 7.4. The impregnation of CE into KBC provided biocomposites that can enlarge the range of BC in the biomedical application.

Background: Sakacin-A due to its specific antimicrobial activity may represent a good candidate to develop active packaging solutions for food items supporting Listeria growth. In the present study a protein extract containing the bacteriocin sakacin-A, produced by Lactobacillus sakei Lb 706 in a low-cost culture medium containing deproteinized cheese whey, was adsorbed onto cellulose nanofibers (CNFs) to obtain an active material to be used as a mat (or a separator) in direct contact with foods., Results: The applied fermentation conditions allowed 4.51 g L -1 of freeze-dried protein extract to be obtained, characterized by an antimicrobial activity of near 16 700 AU g -1 , that was used for the preparation of the active material by casting. The active material was then characterized by infrared spectra and thermogravimetric analyses. Antimicrobial trials were carried out in vitro using Listeria innocua as indicator strain; results were also confirmed in vivo, employing smoked salmon fillets intentionally inoculated with Listeria innocua: its final population was reduced to about 2.5-3 Log cycles after 28 days of storage at 6 °C in presence of sakacin-A, compared with negative control mats produced without the bacteriocin extract., Conclusion: This study demonstrates the possibility of producing an antimicrobial active material containing sakacin-A absorbed onto CNFs to decrease Listeria population in smoked salmon, a ready-to eat-food product. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Over the recent years, the exploitation of antibacterial performance of lignin and its subsequent usage as bacteriostatic additives has gained increasing interests. However, due to the restriction from structural heterogeneity, the antibacterial activity of lignin is always modest and unstable (especially against Gram-negative bacteria). In this regard, we proposed a facile one-step ethanol fractionation process to decrease the heterogeneity of lignin and, therefore, improve its antibacterial activity. Two fractions (Fs and Fi, 95% ethanol soluble and insoluble fraction, respectively) were obtained from bamboo kraft lignin (BKL) and their antibacterial effectiveness was compared. The results showed that the antibacterial activity of Fs increased significantly compared to that of BKL. On the contrary, Fi barely exhibited inhibitory effect on the growth of two Gram-positive bacteria and even promoted the growth of two Gram-negative bacteria. The much lower phenolic-OH content in Fi was an important reason for the absence of antibacterial activity. Besides, the growth promotion of Gram-negative bacteria by Fi was possibly caused by the formation of insoluble carriers for bacteria growth due to the poor water-solubility of Fi. Accordingly, after the elimination of Fi, the one-step fractionation significantly enhanced the antibacterial activity of lignin against both Gram-positive and Gram-negative bacteria., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In the present study, in order to improve the properties of nanostarch-based nanocomposite film for food packaging, a type of nanocomposite film based on corn nanostarch (CNS) as the matrix and modified cellulose nanocrystals (modified-CNCs) as the reinforcement was prepared using a solution casting method. The cellulose nanocrystals (CNCs) were modified by a two-step method in which they were initially crosslinked with citric acid, and subsequently amidated with chitosan. Then, a type of CNS/modified-CNCs nanocomposite film with different content levels of modified-CNC were prepared and characterized using Fourier Transform Infrared spectroscopy (FTIR); X-ray Photoelectron Spectroscopy (XPS); X-Ray Diffraction (XRD); Differential Scanning Calorimetry (DSC); and Scanning Electron Microscopy (SEM). It was observed that when compared with the pure CNS film, the 8.0 wt% modified-CNCs loaded nanostarch-based nanocomposite film had displayed a 230.0% increase in tensile strength. And the moisture absorption ability had decreased by 25.6%; water vapor permeability had decreased by 87.4%; and the water contact angle value had increased by 18.1%. Also the results of this experimental study had revealed that the CNS/modified-CNCs nanocomposite film had displayed better antimicrobial activities against E. coli and S. aureus bacteria when compared with the pure CNS film., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Filtration is a promising water treatment method to purify drinking water. To develop highly efficient drinking water filter paper, water-resistant cellulose foam paper with a high wet strength property was fabricated using diverse metal oxide (e.g., copper oxide (CuO), zinc oxide (ZnO), and silver oxide (Ag 2 O)) nanoparticles. These nanoparticles were synthesized using the hydrothermal reaction method. Their morphological structures were studied using a field emission scanning electron microscope (FESEM). The presence of coated nanoparticles on the cellulose foam filter was verified by energy dispersive X-ray spectroscopy (EDX) methods. The antibacterial performance of different types of modified cellulose foam filters was studied against E. coli, P. aeruginosa, B. subtilis, and B. cereus strains using the zone of inhibition test. The antibacterial profile of the cellulose foam filter impregnated with Ag 2 O nanoparticles, when tested against different types of bacteria, exhibited higher antibacterial activity than the cellulose foam filter impregnated with ZnO and CuO nanoparticles., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The aims of the current study were to evaluate the antibacterial effects of cellulose nanofiber (CNF), chitosan nanofiber (ChNF), CNF/ChNF combination and chitosan alone (Ch) against the isolated bacterial contaminations from the surface of Iranian banknotes using biochemical, disc diffusion and molecular analyses. The results unveiled that the CNF did not show the significant antibacterial effect against isolated bacterial strains, whereas the combination of CNF/ChNF (at concentration 100 μg/disc 1:1) exhibited the synergistic effects against Stenotrophomonas maltophilia. Also, ChNF (100 μg/disc) and Ch (100 and 200 μg/disc) displayed dose-dependent antibacterial effects against the sensitive bacteria including Bacillus subtilis, Bacillus pumilus, Micrococcus sp. Kosakonia cowanii, Brevibacterium frigoritolerans, Escherichia coli standard ATCC 25922, Staphylococcus aureus standard ATCC 25923. On the other hand, chitosan displayed the highest inhibitory effects against Gram-positive bacteria. Our results showed that the coating of banknotes with these compounds is a novel strategy to reduce the bacterial contaminations and increase the durability (or quality) of banknotes, without being toxic to the surrounding environment., (Copyright © 2018 Elsevier B.V. All rights reserved.)

A functionalized paper based on gold nanoparticles (Au NPs) conjugated graphene oxide (GO) was developed for near-infrared (NIR) laser triggered photothermal ablation against infectious bacterial pathogens. Firstly, quaternized carboxymethyl chitosan (QCMC) not only acted as reducing agent to synthesize Au NPs, but also functioned as coupling agent to link up Au NPs with GO. Au-QCMC-GO(+) was supposed to synergistically intensify the photothermal effect, which was then mixed with nanocellulose to form a functionalized paper via vacuum filtration. The photothermal efficiency, antibacterial treatment and mechanical property of Au-QCMC-GO(+)/nanocellulose paper were investigated. Excited by NIR laser irradiation, Au-QCMC-GO(+)/nanocellulose paper generated a temperature rise over 80 °C, sufficient for photothermal ablation upon both Gram-positive bacteria (Bacillus subtilis and Stapylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Additionally, Au-QCMC-GO(+)/nanocellulose paper showed a remarkable enhancement in tensile strength, bursting index and tear index compared to those of pure nanocellulose paper., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The current study focuses on the analysis of in vitro biological activity of extract from bark of Norway spruce (Picea Abies), which can find potential application in food and cosmetic industry and pharmacology. Milled bark was subjected to Soxhlet extraction and supercritical fluid extraction to obtain two ethanol extracts. These extracts were further used to obtain their pre-extracts to n-hexane. It was investigated whether beta-sitosterol exhibits bacteriostatic activity necessary to observe antimicrobial and antifungal activity of methyl dehydroabiatate. This synergic effect and bacteriostatic activity of beta-sitosterol have not been previously reported. The greatest inhibition zone of n-hexane pre-extracts was confirmed in bacterium Pseudomonas aeruginosa (0,9 - 1,5 cm) and yeast Alternaria alternata (0,7 - 1,6 cm). It is novel, the antioxidant, antimicrobial and antifungal activity of spruce bark extracts assessed in terms of food and cosmetic fortification., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Bacterial infection and uncontrolled bleeding are the major challenges facing the wound treatment. In order to solve these problems, we have devised a green nanocomposite hydrogel by introducing the aminated silver nanoparticles (Ag-NH 2 NPs) and gelatin (G) to carboxylated cellulose nanofibers (CNF). Interpenetrating polymeric network (IPN) was formed by interaction of multicomponent, leading to the non-covalent (dynamic ionic bridges) crosslinked hydrogel CNF/G/Ag. The produced hydrogel dressing with 0.5 mg/mL Ag-NH 2 NPs (CNF/G/Ag 0.5 ) demonstrated stronger mechanical, self-recovery, antibacterial properties, satisfactory hemostatic performance, and appropriate balance of fluids on the wound bed (2093.9 g/m 2 per day). More importantly, the wound healing model evaluation in vitro and in vivo of CNF/G/Ag 0.5 showed an outstanding biocompatibility (∼100% infected cell viability) and wound healing efficacy (∼90% healed and 83.3% survival after 14 days). Our study paved a highly promising approach to improve the performance of cellulose-based hydrogel dressing and would also be useful for developing ideal skin wound dressings by other green materials., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A novel cellulose-based antibacterial material, namely silver nanoparticles@ metal-organic frameworks@ carboxymethylated fibers composites (Ag NPs@ HKUST-1@ CFs), was synthesized. The results showed that the metal-organic frameworks (HKUST-1) were uniformly anchored on the fiber's surfaces by virtue of complexation between copper ions in HKUST-1 and carboxyl groups on the carboxymethylated fibers (CFs). The silver nanoparticles (Ag NPs) were immobilized and well-dispersed into the pores and/or onto the surfaces of HKUST-1 via in situ microwave reduction, resulting in the formation of novel Ag NPs@ HKUST-1@ CFs composites. The antibacterial assays showed that the as-prepared composites exhibited a much higher antibacterial activity than Ag NPs@ CFs or HKUST-1@ CFs samples., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The papers have a porous structure which can be a suitable medium for the growth of bacteria. Therefore, in the sanitary papers, creation of a suitable antibacterial property is necessary. In this way, the plant extracts were prepared using solid-liquid extraction method from the Rosmarinus officinalis, Olea europaea, Mentha spicata and Punica granatum. Relatively, the total phenol and flavonoid contents were determined according to colorimetric method. Their antioxidant activity was evaluated using DPPH method. The extracts were sprayed on the surface of the handsheets, and then their antibacterial activity was investigated. The results showed that extracts from the P. granatum has the highest phenol (5.82%) and antioxidant activity (71.13%), while the extract from the R. officinalis had the highest flavonoid (4.23%) and antibacterial activity (90.43%). Hence, it can be concluded that these two extracts could be the suitable combinations to create desirable antibacterial properties in the manufacture of papers with sanitary purposes.

This article deals with evaluating the role of cellulose origin, from wood and non-wood, on preparing green CMC-Ag complex as biological active agent. Viscose pulp as well as bagasse and rice straw pulps were used in preparation of CMCs, followed by complexation with AgNO 3. The complex structure (free-Ag, IR-spectra and TGA), morphology (TEM), antibiological and anti-tumor activities were studied. The data revealed that, the main interaction between CMC and silver is occurred via carboxylate groups and ether link of 1ry alcohol, with formation stable 5-membered ring structure. For the case of RS-based CMC-Ag complex the interaction between COO groups and silica included RS is also possible, via hydrogen bonds. These complexes have anti-biological especially towards gram positive bacteria (B.subtilis, NCID-3610), and uni- and multi cellular fungi. AgNPs from viscose (VCMC-Ag complex) has relatively higher anti-tumor activity for breast cancer MCF-7 in vitro than bagasse-based CMC-Ag complex (BCMC-Ag complex) with IC 50 128μg/ml (as Ag). It is interesting to note that; viscose-based CMC-Ag complex (VCMC-Ag) has higher efficient behaviour as bioactive agent than literature reported agents, e.g., Pyridine derivative (∼300μg/ml)., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Biodegradable food packaging is sustainable and has a great application prospect. PLA is a promising alternative for petroleum-derived polymers. However, PLA packaging suffers from poor barrier properties compared with petroleum-derived ones. To address this issue, we designed bilayer films based on PLA and Pickering emulsions. The formed bilayer films were compact and uniform and double layers were combined firmly. This strategy enhanced mechanical resistance, ductility and moisture barrier of Pickering emulsion films, and concomitantly enhanced the oxygen barrier for PLA films. Thymol loadings in Pickering emulsion layer endowed them with antimicrobial and antioxidant activity. The release profile of thymol was well fitted with Fick's second law. The antimicrobial activity of the films depended on film types, and Pickering emulsion layer presented larger inhibition zone than PLA layer, hinting that the films possessed directional releasing role. This study opens a promising route to fabricate bilayer architecture creating synergism of each layer., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Tea polyphenols have received much attention from the pharmaceutical and food industries owing to their extraordinary antioxidant and antibacterial characteristics. However, tea polyphenols are very unstable in processing and storage, since they are sensitive to the environmental factors like temperature, light and pH. Therefore, the effective application of tea polyphenols requires a protective mechanism to maintain its activity. The utilization of compounded tea polyphenols, instead of raw materials, can potentially help to improve their stability. This review focuses on the summarization of the compounding technologies for tea polyphenols, including physical technologies, chemical-interfacial technologies and nano-scale compounding technologies. Of which, the emerging nano cellulose bio-carrier, as a promising technology, is particularly proposed., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Aims: The aim of this study was to examine the antimicrobial properties of novel aqueous natural rapeseed oil/saline emulsions containing different soluble components of spruce resin., Methods and Results: The composition of aqueous resin emulsions was analysed by GC-MS and their antimicrobial properties were studied with challenge tests and with turbidometric assays. The emulsions were strongly antimicrobial against common Gram-positive and Gram-negative bacteria (including MRSA) as well as common yeasts. Furthermore, they inhibited the biofilm formation and eradicated the microbial biofilms on tested microbes. Characteristic for the emulsions was the presence of oxidized resin acids. Other main components present in emulsions, such as lignans and coumaric acids, were not antimicrobial, when tested separately., Conclusions: The results indicated that the oxidized resin acids were the antimicrobial components in the emulsions. Also, there appears to be a stoichiometric relationship between the number of resin acid molecules and the number microbe cells in the antimicrobial action., Significance and Impact of the Study: The fact that these solutions do not contain abietic acid, which is the main allergenic compound in resins, suggests that these solutions would be suitable, well-tolerated antimicrobials for various medical applications. The aqueous formulation will also allow the expansion of the use of these emulsions in from medical applications to the food preservatives and disinfectants., (© 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of the Society for Applied Microbiology.)

The controlled synthesis of silver nanoparticles (AgNPs) using cell-free filtrate of Fusarium oxysporum fungus was investigated. The effect of fungal incubation period on nanoparticle formation and nitrate reductase enzyme activity was studied using UV-visible spectroscopy and Harley assay, respectively. The highest AgNP formation was observed in the cell-free filtrate of biomass harvested at the early stationary phase where the NR enzyme activity is the maximum. Mixing of the cell-free filtrates of fungal cultures obtained at 23, 28, and 33 °C with silver nitrate solution confirms the higher productivity of AgNP biosynthesis using the cell-free filtrate of fungus incubated at 28 °C. The effect of some factors such as carbon and nitrate sources and light in fungal incubation period on nitrate reductase induction and AgNP formation was also evaluated. In conclusion, increasing nitrate and carbon sources and presence of light induced NR enzyme and produced AgNPs with smaller size, higher monodispersity, and productivity. Results revealed that the presence of ammonium prevents the NR enzyme secretion and causes to the lower productivity of AgNPs.

Biodegradability and antimicrobial activity of food packaging materials are among the most attractive parameters in modern food industries. In order to develop biodegradable poly-lactic acid (PLA) film to antibacterial nanocomposites, different concentration of Zataria multiflora Bioss. essential oil (ZME), propolis ethanolic extract (PEE) and cellulose nanofiber (CNF) were incorporated to the polymer by solvent casting method. The resulting films were characterized by mechanical and physical tests and their antimicrobial application was evaluated in-vitro against four common foodborne pathogens and in vacuum-packed cooked sausages during refrigerated storage. Mechanical examination revealed that addition of ZME and PEE made films more flexible and incorporation of CNF improved almost all mechanical parameters tested. Moreover, according to physical analysis, incorporation of 0.5% v/v ZME to the composite primary solutions improved water vapor permeability of the resulting films. Almost all of the active films were effective against the tested bacteria except for PLA/PEE films, and maximum antibacterial effects recorded for the films containing both ZME and PEE. Based on the microbiological and sensory evaluation of the sausages, all of the PLA/1%ZME/PEE composites increased the shelf life to >40days. The results indicate that incorporation of natural antimicrobial substances such as ZME and PEE to packaging material could be an interesting approach in development of active packaging material without significant negative effect on polymer technical properties., (Copyright © 2017 Elsevier B.V. All rights reserved.)