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Background Food packaging is a globally relevant and widely used technique for food preservation. Natural, biodegradable, and bioavailable polymers are gaining popularity in the field of food packaging. Cellulose and its derivatives are amongst the most abundant and widely used polymers in the packaging industry. There are many natural sources for cellulose, and they can also be obtained from bio-wastes and agricultural wastes. Thus, it is available in large quality and is cost effective. Scope and approach In this review, we discussed the importance, functioning, properties, and characteristics of cellulose and its derivatives for food packaging. The application of cellulose in food packaging from the discovery of cellulose in 1839–2020 was introduced in this article. Which includes its use for the preservation of fruits and vegetables is discussed in detail, and its application as carrier of various natural antibacterial and antioxidant compounds was introduced. Various types of composite films prepared using cellulose and its derivatives are also discussed in this review. Furthermore, numerous functional properties of cellulose have been mentioned. Key findings and conclusion Cellulose is one of the most important polymers in the food industry. This study explores its properties and its encapsulations and stabilization of compounds without altering their properties. Through extensive study of existing literature on the subject, this review compiles the information relevant to the use of cellulose in food preservation. In addition, various future considerations are further presented.

Polylactic acid (PLA)/nano-TiO2(TiO2 NPs)/Graphene oxide (GO) nano-fibrous films were prepared by ultrasonic assisted electrostatic spinning technology, and the effects of TiO2 NPs:GO mass ratio and ultrasonic power on film morphology and mechanical, thermal, barrier and antibacterial properties were investigated. The addition of TiO2 NPs and GO can significantly increase the tensile strength and elongation at the break of PLA nano-fibrous films, and improve the water barrier properties of the nano-fibrous films. The antibacterial experiment showed that the inhibition rates of the nano-fibrous films against Escherichia coli and Staphylococcus aureus after 24 h exposure to UV irradiation reached 94.4 ± 1.8% and 92.6 ± 1.7% At the same time, the fresh-keeping packaging experiment of green peppers at room temperature, through the determination of hardness, soluble solids, chlorophyll content to determine the degree of decay of green pepper, it showed that PLA/TiO2 NPs/GO nano-fibrous films can better maintain the sensory quality of green peppers, delay the rate of spoilage of green peppers, and prolong the preservation period of green peppers.

A gold-catalysed cascade C(sp3)–H alkynylation/oxy-alkynylation of acceptor-substituted carbonyl compounds with hypervalent iodine(III) reagents for the synthesis of tetra-substituted furans is described. This reaction involves two Au(I)/Au(III) catalytic cycles and proceeds through a C(sp3)–H alkynylation of a substituted ketone and a subsequent oxy-alkynylation of the generated 2-alkynyl ketone. This mild and simple method can tolerate a wide range of functionalities, offering distinct advantages over previous methods using PIDA as the external oxidant. Furthermore, a gram-scale synthesis is feasible and the synthesized furan product was readily transformed into other related compounds.

In this study, chitosan/halloysite nanotubes/tea polyphenol (CS/HNTs/TP) nanocomposite films were prepared by the solution casting method. The scanning electron microscopy (SEM) result showed that the nanocomposite film with a CS/HNTs ratio of 6:4 and a TP content of 10% (C6H4-TP10) had a relatively smooth surface and a dense internal structure. The water vapor barrier property of the nanocomposite film was improved due to the tortuous channels formed by the HNTs. However, the swelling degree and water solubility of the nanocomposite films were decreased. The nanocomposite films have a good antioxidant capacity. Antibacterial experiments showed that the C6H4-TP10 nanocomposite film had certain inhibitory effects on the growth of both E. coli and S. aureus. In addition, we used 3D printer to verify the printability of the optimal formulation of the film-forming solution. Overall, this strategy provides a simple approach to construct promising natural antioxidants and antibacterial food packaging.

Encapsulation effectively delays the volatilization of lemon essential oil (LEO). Here, various chitosan (CS)-LEO nanoparticles were prepared by emulsification using different CS and Tween-80 concentrations and CS:TPP and CS:LEO ratios. The CS-LEO nanoparticles were spherical, small in size (58 ± 9 nm), had a low polydispersity index (0.15), and were highly stable under the right conditions. FTIR spectra indicated that they were fully encapsulated in the films. The composite films are characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscope (SEM) and X-ray diffraction (XRD). Relative to grass carp collagen (GCC) films, edible GCC/CS-LEO had lower oxygen permeability (OP), higher tensile strength (TS), and higher elongation at break (EB). The LEO release rate increased with decreasing GCC:CS-LEO ratio. At GCC:CS-LEO ratio = 7:3, a maximum LEO release rate of 83.6 ± 9.7% was achieved over 15 days. GCC/CS-LEO films can effectively inhibit lipid oxidation, prevent microbial proliferation, and delay the deterioration of pork at 4 °C for 21 days.

Fluorescent nanomaterials have been widely used in biological imaging due to their selectivity, sensitivity, and noninvasive nature. These characteristics make the materials suitable for real-time and in situ imaging. However, further development of highly biocompatible nanosystems with long-lasting fluorescent intensity and photostability is needed for advanced bioimaging. We have used electrospraying to generate gelatin methacryloyl (GelMA)-based fluorescent nanoparticles (NPs) with chemically conjugated rhodamine B (RB). The extent of conjugation can be controlled by varying the mass ratio of RB and GelMA precursors to obtain RB-conjugated GelMA (RB-GelMA) NPs with optimal fluorescent properties and particle size. These NPs exhibited superior biocompatibility when compared with pure RB in in vitro cell viability and proliferation assays using multiple cell types. Moreover, RB-GelMA NPs showed enhanced cell internalization and improved brightness compared with unconjugated RB. Our experiments demonstrate that engineered RB-GelMA NPs can be used as a biocompatible fluorescent label for bioimaging.

This paper presents a comprehensive investigation of the effects of cutting parameters on the surface integrity of milled γ-TiAl alloys. Surface topography, surface roughness, surface defects, plastic deformation, micro-hardness, chip morphology, and tool wear of the milled γ-TiAl alloys were analyzed. The results indicate that the feed rate had the greatest influence on the surface topography and surface roughness. The value of surface roughness increased with the increase in cutting depth and feed rate. However, with the increase in cutting speed, it initially increased and then decreased. The minimum surface roughness was found to be 0.066 μm. The thickness of the plastic deformation layer and the micro-hardness value increased with the increase in cutting depth and feed rate. Also, they initially increased and then decreased with the increase in cutting speed. The minimum thickness of the plastic deformation layer was 15 μm and the depth of the hardened layer on the processed surface varied between 55 and 70 μm. The chip morphology was closely related to the quality of the processed surface. When the cutting depth and feed rate decreased, the chip morphology was transformed from segmented to nearly smooth. When the cutting depth and feed rate reached a critical point, plastic processing of γ-TiAl was achieved. Compared to brittle deformation, a more favorable processed surface was obtained. Finally, the comparison tests of tool wear were carried out with dry and flood coolant cutting. When the cutting speed reached 120 m/min in dry cutting, the tool life was very poor, and the cutting distance was only 1 m. However, the tool life was generally good when cutting with low cutting speed under the following conditions: vc = 60 m/min, ap = 0.1 mm, and fz = 0.01 mm/tooth. Under these conditions, the cutting distance was 60 m in dry cutting with the tool wear of 0.2 mm and 120 m in flood coolant cutting with the tool wear of 0.1 mm. The tool life in flood coolant operation was better than that of dry operation. The tool life decreased to 30 m when cutting with high cutting speed or feed rate (ap = 0.25 mm or fz = 0.025 mm/tooth).

Magnetoresistance effects are used in a variety of devices including hard disk drives and magnetic random access memories. In particular, giant magnetoresistance and tunnelling magnetoresistance can be used to create spin valves and tunnel junctions in which the resistance depends on the relative magnetization orientations of two ferromagnetic conducting layers. Here, we report a magnetoresistance effect that occurs in a platinum layer deposited on a magnon junction consisting of two insulating magnetic yttrium iron garnet (YIG) layers separated by an antiferromagnetic nickel oxide spacer layer. The resistance of the platinum layer is found to depend on the magnetization of the YIG layer in direct contact with it (an effect known as spin Hall magnetoresistance), but also the magnetization of the adjacent YIG layer in the junction. The resistance of the platinum layer is higher when the two YIG layers are aligned antiparallel than when parallel. We assign this behaviour to a magnonic nonlocal spin Hall magnetoresistance in which spin-carrying magnon propagation across the junction affects spin accumulation at the metal interface and hence modulates the spin Hall magnetoresistance. The effect could be used to develop spintronic and magnonic devices that have spin transport properties controlled by an all-insulating magnon junction and are thus free from Joule heating. A magnetoresistance effect that occurs in a platinum layer deposited on a magnon junction consisting of two insulating magnetic yttrium iron garnet layers separated by an antiferromagnetic nickel oxide spacer layer could be used to create spintronic and magnonic devices that are free from Joule heating.

In this study, a coaxial electrospray process was used to produce nanoparticles, in which thymol was encapsulated in a core–shell of zein and shellac. We then investigated fluid velocity and solution concentrations on the electrospray. Scanning electron microscopy revealed that the thymol/zein/shellac particles prepared at a flow rate ratio of 0.6:0.3 mL/h were rounder with smaller diameters. The highest encapsulation efficiency of thymol was 81.34%, the average particle size was 606.53 nm, and the retention rate of thymol was 68.74% after 30 days. Moreover, we investigated the thermal stability, antimicrobial activity, and simulated gastrointestinal release curves of the nanoparticles. Finally, the nanoparticles were used as a coating for fresh-cut cantaloupe. Compared with the blank nanoparticle control group, the coating significantly extended the shelf life of cantaloupe to 16 days. Our results indicate that these nanoparticles have great potential for application in food preservation.

In this study, poly (e-caprolactone) (PCL)/zein/Ag nanoparticle (AgNP) fibrous membranes were prepared by ultrasonication-assisted electrospinning. The effects of the AgNP content and ultrasonication time on the membrane morphology, chemical structure, biodegradability, mechanical properties, antibacterial/antiviral activity, and air filtration performance were studied. The best-performing membrane (AgNP content = 1% (w/v), sonication time = 30 min) exhibited a bead-on-string morphology, an air permeability of 93.6 ± 1.5 mm s−1, and the Escherichia coli and Staphylococcus aureus removal efficiencies of 98.1 ± 1.2% and 97.4 ± 2.5%, respectively. In an experiment with E. coli phage, the above-mentioned membrane exhibited a 97.1 ± 2.1% virus removal efficiency after 60 min. The high performance of this bead-on-string membrane for air filtration was ascribed to the low packing density due to the presence of open interconnected beaded airflow channels and small beads.

International audience; In this study, polyvinyl alcohol (PVA) was used as a film-forming substrate, added to extracted tea polyphenols (TPs) in various ratios and processed with ultrasonication to form films using the tape-casting method. The effects of ultrasonic processing duration on the properties of PVA/TP antibacterial active materials were explored via material property testing. The results showed that, overall, ultrasonic processing degraded the tensile strength and elongation at break of the composite films. When PVA/TP composite films with a PVA-to-TP mass ratio of 8:2 were processed with ultrasonication for 30 min, the swelling capacity was (740.19 +/- 64.67)% and solubility was (5.26 +/- 1.31)%. Ultrasonication also improved the degradability and barrier properties of composite films. Moreover, 8/2 composite films with the PVA/TP ratio of 8:2 exhibited excellent bacteriostatic properties; after ultrasonication processing, the films had a bacteriostatic rate of (95.5 +/- 4.2)% and (91.8 +/- 3.7)% against Staphylococcus aureus and Escherichia coli, respectively, making them suitable for use as antibacterial active materials in food packaging.

Thrombosis and infections of extracorporeal circuits and indwelling medical devices are the two major life-threatening complications faced in clinical practice. Herein, we report a novel and facile metal–phenolic–amine surface modification strategy to engineer a multifunctional coating on these devices to combat thrombosis and infection. This strategy is inspired by the metal–catecholamine coordination complex of [Fe(dopa)3] in mussels, in which Cu(II) ions (metal), plant polyphenol gallic acid (phenol) and cystamine (amine) are employed to fabricate a copper–phenolic–amine network. Our in vitro and in vivo experiments reveal that the resultant Cu(II)-chelating coatings endow the modified tubing with not only durable antibacterial properties, but also capability to persistently generate anticoagulant therapeutic nitric oxide (NO) gas in the presence of endogenous S-nitrosothiols (RSNO) from fresh blood. We anticipate that our simple and multifunctional coating strategy will be a milestone in the development of surface engineering, especially that of biomedical devices.

In this study, we developed an in-package colorimetric paper to monitor the ripeness of kiwifruit by detecting the release of aldehydes. Strongly hydrophobic composite films were prepared using chitosan as the matrix and beeswax as an additive. A piece of cellulose paper containing methyl red and bromocresol violet as color indicators was heat-sealed between two hydrophobic films to protect the indicators from the effects of fruit respiration and transpiration. The nucleophilic addition reaction between aldehydes and OH− (Cannizzaro reaction) changes the pH in the paper and triggers a color change in the indicators. As the kiwifruit ripens, the colorimetric paper changes from bluish-purple to dark red and then gradually to red. A mobile phone application was further used to measure the RGB values and link them to kiwifruit ripeness. This intelligent paper can be used for the accurate and convenient monitoring of produce in real time.

Polyacrylonitrile (PAN)/β-cyclodextrin (β-CD) composite nanofibrous membranes immobilized with nano-titanium dioxide (TiO2) and graphene oxide (GO) were prepared by electrospinning and ultrasonic-assisted electrospinning. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD) confirmed that TiO2 and GO were more evenly dispersed on the surface and inside of the nanofibers after 45 min of ultrasonic treatment. Adding TiO2 and GO reduced the fiber diameter; the minimum fiber diameter was 84.66 ± 40.58 nm when the mass ratio of TiO2-to-GO was 8:2 (PAN/β-CD nanofibrous membranes was 191.10 ± 45.66 nm). Using the anionic dye methyl orange (MO) and the cationic dye methylene blue (MB) as pollutant models, the photocatalytic activity of the nanofibrous membrane under natural sunlight was evaluated. It was found that PAN/β-CD/TiO2/GO composite nanofibrous membrane with an 8:2 mass ratio of TiO2-to-GO exhibited the best degradation efficiency for the dyes. The degradation efficiency for MB and MO were 93.52 ± 1.83% and 90.92 ± 1.52%, respectively. Meanwhile, the PAN/β-CD/TiO2/GO composite nanofibrous membrane also displayed good antibacterial properties and the degradation efficiency for MB and MO remained above 80% after 3 cycles. In general, the PAN/β-CD/TiO2/GO nanofibrous membrane is eco-friendly, reusable, and has great potential for the removal of dyes from industrial wastewaters.

In this study, a bilayer antibacterial chromogenic material has been prepared using chitosan (CS) and hydroxyethyl cellulose (HEC) as the inner substrates, mulberry anthocyanins (MA) as natural tracers, and titanium dioxide nanoparticles (nano-TiO2) as bacteriostatic agent for the outer layer. By investigating its apparent viscosity and suitability for three-dimensional (3D) printing, the optimal ratio of the substrates was determined to be CS:HEC = 3:3 (CH). The CH viscosity was observed to be moderate. The printing process was consistent with no breakage or clogging, and the printed image was of high stability, and not susceptible to collapse and diffusion. Scanning electron microscopy and infrared spectroscopy indicated that the intermolecular binding between the substances exhibited good compatibility. Nano-TiO2 was evenly distributed in the CH, and no agglomeration occurred. The inner membrane fill rates affected the overall performance of the chromogenic material, with strong inhibitory effects against Escherichia coli and Staphylococcus aureus at different temperatures, as well as strong color stability. The experimental results indicated that the double-layer antibacterial chromogenic material can, to a certain extent, extend the shelf life of litchi fruit and determine the extent of its freshness. Therefore, from this study, we can infer that the research and development of intelligent materials have a certain reference value.

Ultrasonication-assisted solution casting was used to prepare polyvinyl alcohol (PVA)/sodium carboxymethyl cellulose (CMC)/nano-ZnO/multilayer graphene nanoplatelet (xGnP) composite films, the performances (mechanical properties, water vapor permeability (WVP), biodegradability and antibacterial activity) of these films were investigated as a function of the ZnO NPs:xGnP mass ratio and ultrasonication time. Intermolecular interactions among ZnO NPs, xGnP and the PVA/CMC matrix were shown to improve WVP, while X-ray diffraction and scanning electron microscopy analyses revealed that the internal reticular structure of ultrasound-treated PVA/CMC/ZnO NPs/xGnP composite films was in a fluffier state than that of the untreated composite films and the PVA/CMC film. The incorporation of ZnO NPs and xGnP into the composite film reduced its tensile strength and elongation at break, and increased antibacterial activity and biodegradability. In addition, we carried out the experiment of strawberry preservation and measured weight loss ratio, firmness, content of total soluble solids and titration acid. Finally, the composite film of 7:3 had the best preservation effect on strawberries. Thus, the obtained results paved the way to develop novel biodegradable composite films with antimicrobial activity for a wide range of applications.

In this study, Lactococcus lactis was embedded in a film of corn starch (NS) and carboxymethyl cellulose (CMC) prepared using a casting method. At a CMC:NS ratio of 5:5, the composite film had the best comprehensive properties. Scanning electron microscopy images clearly showed that L. lactis was effectively embedded. The film with 1.5 % L. lactis showed the best performance and the lowest water vapor transmission rate (5.54 × 10-11 g/m s Pa. In addition, the edible film retained a viable count of 5.64 log CFU/g of L. lactis when stored at 4 °C for 30 days. The composite film with 1.5 % L. lactis showed the highest release of nisin (3.35 mg/mL) and good antibacterial activity against Staphylococcus aureus (53.53 %) after 8 days. Therefore, this edible film is a viable alternative antimicrobial strategy for the active packaging of foods containing low moisture content.

In this study, we prepared gelatin and chitosan as wall materials, and composites with a controlled release capability in a weak acidic environment were synthesized for loading and protecting anthocyanins. Fourier-transform infrared spectroscopy and scanning electron microscopy were used to assess the properties of the nanoparticles. The loading efficiencies and oxidation resistances of the proposed substances were measured. Under optimal conditions, the anthocyanins exhibited a loading efficiency of 83.81 %, and suitable long-term storage capacity at room temperature with a retention rate of ∼50 % after 15 d. When the nanoparticles were used for detecting the milk freshness, spoiled milk exhibited a reddish color, whereas the color of fresh milk did not change. Moreover, these nanoparticles exhibited a stable chroma in milk for 0–16 h. Therefore, the proposed pH responsive nanoparticles can provide a possibility for the dynamic monitoring of milk quality changes, or provide some reference value for future related research.

International audience; Active biodegradable packaging films were developed with polyvinyl alcohol (PVA), chitosan (CS) and D-Limonene (DL). The effect of various DL content levels (0%, 2.5%, 5%, 7.5%, and 10% w/w) on the structural, mechanical, biodegradable and antimicrobial properties of PVA/CS films was systematically studied. Good compatibility between DL and PVA/CS, and good dispersion of DL in the PVA/CS matrix were demonstrated by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). PVA/CS films greatly improved their antibacterial, mechanical and barrier properties, which are associated with the considerable biodegradability, after they were incorporated with DL. However, the overloading with DL may weaken hydrogen bonds between polymer chains, resulting in the negative effects on the physical performances of the film. Particularly, the PVA/CS/DL-5% film showed the highest water contact angle and transmittance value, and also showed effective preservations of packaged mango fruits during 10 day of storage at 20 +/- 2 degrees C, based on the characterization by fruits weight loss, decay rate, firmness, titratable acidity, soluble solids, and ascorbic acid. Consequently, DL/PVA/CS composite films may be a promising eco-friendly packaging material for food preservation. (C) 2018 Published by Elsevier B.V.

In this study, chitosan (CH), mulberry anthocyanin (MA), and lemongrass essential oils (LEO) were used as an interlayer using a 3D printer. Further, cassava starch (CS) was used as a protective layer to form indicator films. The indicator films containing LEO showed significant antioxidant and antibacterial properties, and the release rate of LEO increased with a rise in pH. When chilled pork spoiled, the color of the indicator films changed from red to gray-blue, and the RGB values could be automatically analyzed by a smartphone application to determine pork freshness. These films hold implications as easy-to-use indicators of meat freshness, with great potential for monitoring food spoilage, as part of an intelligent packaging system.

In this study, Panax notoginseng polysaccharides (PNPS) were extracted using ultrasonic/microwave-assisted extraction (UMAE). Based on single-factor experiments, ultrasonic duration, ultrasonic power, microwave duration, and microwave power were optimized using the response surface methodology (RSM). The results indicated that the optimal extraction parameters were an ultrasonic duration of 10 min, ultrasonic power of 50 W, microwave duration of 4 min, and microwave power of 540 W, which resulted in the highest extraction rate of PNPS at 11.03 ± 0.16%. Scanning electron microscopy images indicated that PNPS exhibited a porous and rough structure. The chemical structure of PNPS was analyzed using Fourier transform infrared spectroscopy and ultraviolet–visible spectroscopy. The molecular weight of PNPS was measured to be 4.148 × 105 Da; moreover, PNPS was found to be composed of glucose, galactose, galacturonic acid, arabinose, glucuronic acid, rhamnose, mannose, and ribose. The DPPH scavenging efficiency of PNPS (5 mg/mL) was evaluated to be 65.74%. Upon in vitro simulated saliva–gastrointestinal digestion, partly digested PNPS was obtained. In addition, differential scanning calorimetry (DSC) analysis and rheological testing results indicated that PNPS exhibited high thermal stability and favorable rheological properties. Therefore, PNPS extracted using UMAE exhibited broad application prospects for functional foods and pharmaceuticals.

In order to increase the stability and the release time of nisin, nisin/Tremella fuciformis polysaccharide nanoparticles (NTNs) were prepared and evaluated based on their uniform particle size dispersion (168–356 nm) and high loading rate (70–86%). The condensation reaction between 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and hydroxysuccinimide (EDC/NHS) amide was successfully used to prepare novel live particles (NTN@LP). When the mass ratio of NTN and LP was 2:1, the bacterial viability (85.6 ± 2.11%) and grafting efficiency (68.8 ± 1.96%) of the NTN@LP were both relatively high. The hemolytic activity and in vitro cytotoxicity indicated that NTN@LP is safe to use in food. The NTN@LPs were then used as natural microbial preservatives in sausages. The pH value, water activity, thiobarbituric acid-reactive substances value, and sensory evaluation of the sausages were used to assess the effect of NTN@LPs on the quality of the sausages during fermentation. NTN@LPs played an important role in reducing and decomposing biogenic amines (BAs) throughout the sausage fermentation process and displayed a strong inhibitory effect on histamine (>95%). Compared to that of the control group, the total amount of BAs in the 2:1 group was reduced by 67.90%. Tyramine content in the 2:1 NTN@LP group decreased by 78.16% compared to that in the control group, while tyramine content in the pure LP group was decreased by only 38.25%. These results indicate that NTN@LP can be potentially applied as a natural microbial preservative in the food industry.

An efficient palladium-catalyzed selective decarboxylation/C–H activation coupling of aryl acid with thiazole and oxazole under the assistance of 1,2,3-triazole ring were developed. This work provides an effective access to build functionalized 1,2,3-triazoles bearing thiazole and oxazole moieties. This method has good substrate compatibility to compose a series of selective heterocyclic compounds in moderate to good yields.

In this study, blended films from poly(vinyl alcohol) (PVA) containing chitosan (CS) were prepared via a simple solution casting and electrospraying method. The structures of the PVA-CS films were characterized by Fourier-transform infrared spectroscopy. The morphologies of the films were observed by scanning electron microscopy. The thermal properties of the PVA-CS films were examined by thermogravimetry. The effects of CS contents on the mechanical properties, oxygen permeability values, water vapor permeation levels, and antibacterial behaviors against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) strains were investigated. Compared to the pure PVA film, the PVA-CS films showed greater elongation at break, lower oxygen permeability, higher water barrier properties, and greater antibacterial activity, especially for the PVA:CS weight ratio of 75:25. The obtained results indicate the PVA-CS film may be a promising material for food packaging applications.

In this study, potassium persulfate, N,N'-methylene bisacrylamide (MBA), and soluble starch (ST) were in situ cross-linked into porous antimicrobial starch particles containing N-halamine functional groups (PST–MBA–Cl). Then, polyacrylonitrile (PAN)/silica aerogel (SA)/zinc oxide (ZnO) beaded fibers containing PST–MBA–Cl particles were prepared by electrospinning. Scanning electron microscopy results demonstrated the uniform dispersion of the PST–MBA–Cl particles and ZnO on the surface and interior of the beaded fiber when the concentration of the PST–MBA–Cl particles was 15%. The composite beaded fibers prepared after chlorination and soaking in zinc salt solutions of different pH values had a higher degree of interior fluffiness. For the analysis of the effectivity of the prepared particles using 108 CFU/mL gram-positive (S. aureus) and gram-negative (E. coli) bacterial human pathogens, the inhibition zone was 15.97 ± 0.12 and 17.81 ± 0.23 mm, respectively. Meanwhile, the degradation efficiency of PAN and SA for the cationic dye methylene blue (MB) was 88.00% ± 1.83%. The PAN/SA/PST–MBA–Cl/ZnO composite beaded fiber showed good antibacterial properties and a fast recovery rate, and its degradation efficiency for MB was retained at ~80% after five cycles. Thus, the PAN/SA/ PST–MBA–Cl/ZnO beaded fibers can be used as an environment-friendly and reusable adsorbing material for the removal of dyes from industrial wastewater.

In this study, we prepared a composite of chitosan (CS), halloysite nanotubes (HNTs), and tea polyphenols (TP) using 3D printing technology. The intermolecular interactions between the components and the printability of the ink were analyzed via Fourier transform infrared (FTIR) spectroscopy and rheological properties. The prepared CS/HNTs-TP composite container exhibited high fidelity and precision. The effects of printing parameters, such as nozzle diameter, air pressure, nozzle height, printing speed, and layer height, on the precision of printed CS/HNTs-TP composite containers were examined. The optimal parameters for printing 3D constructs were found to be 0.8-mm nozzle diameter, 0.4-MPa air pressure, 0.5-mm nozzle height, 30-mm/s printing speed, and 0.3-mm layer height, matching the target model with fine resolution, smooth surface texture, and high precision. The printed CS/HNTs-TP composite container was used for storing blueberries. After 12 days of storage, the blueberries preserved in the CS/HNTs-TP composite maintained a 41.87% weight loss ratio, a 59% decay rate, 9.1% total soluble solids (TSS), 4.1 N firmness, 0.43% titratable acidity (TA), and 14.27% ascorbic acid when compared with those of the control group and CS group. The results indicate that CS/ HNTs-TP composites are highly effective in maintaining the quality of blueberries.

At present, common methods for preparing adsorbents for arsenic removal include electrospinning, tape-casting, and the powder method, but there is still a lack of research on the differences in the adsorption properties of arsenic-removal adsorbents prepared by these three methods. In this study, nine composite adsorbents were prepared by electrospinning, tape-casting, and the powder method with ferric hydroxide as the dopant, and their properties were examined. Scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction confirmed the existence of ferric hydroxide on the surfaces and insides of the composite adsorbents. Differential scanning calorimetry and mechanical performance tests showed that the addition of FeOOH changed the thermal and mechanical properties of the adsorbents. The arsenic(III) adsorption capacity of each composite adsorbent was also determined as well as the effects of pH and temperature. The results showed that polyacrylonitrile/ferric hydroxide (fiber) had the highest arsenic(III) adsorption capacity (11.31 mg/g) under the baseline conditions. When the pH was adjusted to approximately 9, the maximum adsorption capacity increased to 12.41 mg/g. When the control temperature was 15 °C, the maximum adsorption capacity was 12.07 mg/g. After three adsorption cycles, the arsenic(III) removal rate of each composite membrane reached 90%. Overall, the electrospun membranes had the highest adsorption efficiencies among the three types of adsorbents with respect to arsenic removal, and polyacrylonitrile proved to be the best base material. In comparison, polyvinylidene fluoride proved more suitable for tape-casting films and powder adsorbents.

Polyvinyl alcohol (PVA)/titanium dioxide nanoparticles (TiO2 NPs)/3,3′,4,4′-Benzophenone tetracarboxylic acid (BPTA) antibacterial films were prepared by solvent casting and chemical grafting using PVA as the base material and TiO2 NPs and BPTA as antibacterial materials. Scanning electron microscopy results showed that the distribution of TiO2 NPs inside the polymer matrix was substantially uniform. X-ray diffraction (XRD) and FTIR-ATR spectroscopy were used to demonstrate the successful embedding of NPs and the formation of ester bonds in the grafting process, respectively. In the antibacterial experiment, the PVA/1%TiO2 NPs/BPTA film exhibited higher antibacterial activity than other films. Compared with the control group, the surviving population of S. aureus and E. coli decreased by 99.62 ± 0.38% and 98.27 ± 1.47%, respectively. The mechanism of reactive oxygen species (ROS) production was discussed, and the amount of ROS produced by the composite films under light and dark conditions was quantitatively measured. A cycling experiment after quenching ROS showed that the PVA/1%TiO2 NPs/BPTA composite film retained 81.01% and 66.12% of the original charging capacity of the OH• radical and H2O2 after seven cycles. In terms of biodegradability, the degradation performance of the PVA/TiO2 NPs/BPTA composite film was stronger than that of the pure PVA film. Thus, the PVA/TiO2 NPs/BPTA film is considered a promising antibacterial material with superior characteristics of structural stability, reusability, and functionality under both light and dark conditions.

Currently, due to high surface to volume ratio; large availability, rapid kinetics of adsorption and desorption and low cost, the exploitation of microbial biosorption of heavy metals is regarded as a reliable alternative compared to the conventional bioremediation approaches. In parallel with the increasing attractiveness of biosorption research, its pace of advance is also boosted. The barrier that prevent biosorption as an effective method from being applied into wastewater purification is listed, (1) There is not enough data on multi-component biosorption, (2) It remains to be seen that physical-chemical characteristics of different biomasses. (3) Studies on surface modification of strains for enhancement of heavy metals removal efficiency is lack. And extensive literatures involving the mechanism and model of biosorption for particular metal and microbial strains are not available. The present literatures lack systematization, the theory on interaction between lactic acid bacteria and Pb is far from complete. Therefore, the review tries to give a comprehensive explanation about the mechanism of Pb removal from Lactic acid bacteria and provide a brief overview of distinction between biosorption and bioaccumulation, biosorption technology, highlight the underlying features of biosorption and the various affecting factors such as pH, dose required, initial concentration, temperature, and treatment performance as a reference. Biosorption mechanisms can be briefly generalized into several pathways, which are ion exchange, complexation, precipitation, reduction and chelation. Many views holds that complexation is the major absorption mechanisms of Pb. Biosorption mechanisms can be roughly classified as biosorption and bioaccumulation, which have great differences between each other. Biosorption is metabolism-independent but fast, while bioaccumulation is metabolism-dependent but slow. The slight advantages of the bioaccumulation are the metabolite (lactic acid), lactobacillus surface-layers, enzymes and so on. Many factors can greatly affect adsorption process, different factors have different influence and the effects of pretreatment, pH and temperature are relatively greater. Desorption is not a fully reversible process of biosorption, but could not only achieve the goal of the recycle of microorganism, but also contribute to release of trace metal elements. Also the technologies for observation of biosorbents characterics and effect on the metal binding process are reviewed.

A concise and efficient method for the synthesis of etherified 3-(1H-1,2,3-triazol-1-yl)phenyl iodides from 1,4-disubstituted 1,2,3-triazoles under metal-free conditions has been developed. In the presence of ArI(OAc)2, a range of 1,2,3-triazole substrates that contain a hydroxy group underwent a direct O–H arylation and C–H iodination to afford functionalized 1,2,3-triazoles in good to excellent yields.

Background: Arabinoxylan was thought to have the potential to change lipid metabolism and redox homeostasis in human and animal. However, the effect of arabinoxylan on the liver damage induced by high-fat diet needs further exploiting.; Results: Six-weeks-old 30 male Sprague-Dawley Rats were assigned randomly to three groups (n = 10 per group), i.e. a control diet (CON) group, a high-fat diet (HF) group and a high-fat diet supplemented with arabinoxylan (6% AX, HF-AX) group. Results showed that final body weight and liver weight were similar in CON group and HF-AX group, but higher in the HF group. In serum, the HF-AX group showed lower triglyceride concentrations than did the HF group. In liver, higher lipoprotein lipase, hepatic lipase, total lipase, and acyl-CoA oxidase activities and lower triglyceride and cholesterol level were observed in the HF-AX group than in the HF group. For the redox homeostasis, arabinoxylan supplemented in HF increased T-SOD activity and GSH-PX activity and reduced MDA + 4-HNE level in liver and/or compared with those in the HF group. Lipid droplets and liver cell damage were observed in the HF group compared with the CON and HF-AX groups.; Conclusion: Arabinoxylan could improve lipid metabolic disorder and alleviate liver damage in rats induced by high-fat diet via activating lipid catabolism and suppressing lipid peroxidation. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

CuI-catalyzed selective Ullmann C–O coupling of 1,4-disubstituted 1,2,3-triazole bromides with phenols were achieved through the coordination of N(2) atom. The ortho C–Br bond in N(1) aryl can be selectively coupled with phenols, while other C–Br bonds remain inert, generating ortho aryloxyl 1,4-diaryl 1,2,3-triazoles.

Pd(OAc)2-catalyzed direct C–H arylation of an arene triazole template has been explored using the triazole ring as a directing group. The N(3)-ortho C–H bond on C(4) aryl of 1,4-disubstituted 1,2,3-triazoles can be selectively arylated, exclusively affording the expected structures. The diarylated products could be selectively formed when the triazole derivative beared a para substituent on C(4) aryl of the heterocycle, while the monoarylated target molecules resulted from substrates with an ortho or meta substituent.

Based on the excellent biocompatibility of collagen, collagen was extracted from pig skin by acid-enzymatic method. The films were prepared by the self-aggregation behavior of collagen, and the catalase was immobilized by adsorption, cross-linking and embedding. The experiment investigated the effects of glutaraldehyde on the mechanical properties, external sensory properties, and denaturation temperature of the films. The results showed that self-aggregating material could maintain the triple helix structure of pig skin collagen. The self-aggregation treatment and cross-linking treatment can improve the mechanical properties to 53 MPa, while the glutaraldehyde cross-linking agent can increase the denaturation temperature of the pig skin collagen self-aggregating membrane by 20.35% to 84.48 °C. This means that its application to immobilized catalase has better stability. The comparison shows that the catalase immobilized by the adsorption method has strong activity and high operational stability, and the cross-linking agent glutaraldehyde and the initial enzyme concentration have a significant effect on the immobilization, and the activity can reach 175 U g−1. After 16 uses of the film, the catalase was completely inactivated. This study provides a reference for the preparation of a catalase sensor that can be used to detect hydrogen peroxide in food by a catalase sensor.

In this experiment, we studied the effect of poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blend films on the efficiency of passion fruit preservation at 20 &deg, C. The weight loss, shrinkage index, firmness, and total sugar of passion fruit packaged with PLA/PBAT films had no significant differences compared with PE films during 21 days (p &gt, 0.05). PLA/PBAT films can more effectively reduce the rising of ethanol content and delay the total acid, ascorbic acid, and sensory evaluation. Compared with unpackaged (CK) and polyethylene (PE) films, PLA/PBAT films are more conducive to preserve the overall flavor of passion fruit during storage time, in agreement with sensory evaluation, tested by E-nose, E-tongue, and GC-MS, which also proved that it can effectively maintain the edible quality of passion fruit during storage time. We believe that our study makes a significant contribution to literature because it paves the way to the generalization and application of packaging films based on composite antibacterial polymers and facilitates the commercialization of fresh passion fruit as an important health food.

In this research, chitosan (CS) and poly (vinyl alcohol) (PVA) were adopted as a material, methacryloyloxyethyl trimethyl ammonium chloride (DMC) was added in various concentrations and was treated ultrasonically for the formation of films with the use of the polymer blending method. The influences exerted by the ultrasonication period on PVA/CS/DMC antimicrobial active materials underwent material characteristic tests. The consequences revealed that at the break of the compound films, ultrasonication raised the elongation and tensile strength on the whole. Ultrasonication further or also enhanced the light transmittance performance and composite films&rsquo, barrier property. Furthermore, the compound film with a DMC concentration of 2% had good antibacterial properties, the film&rsquo, s inhibition rates against Staphylococcus aureus and Escherichia coli after ultrasonication were 79.23% &plusmn, 1.92% and 72.31% &plusmn, 1.35%, respectively.

In this study, the casting method was used to make chitosan (CS)/corn starch/cinnamaldehyde film, and the preservation performance of the film was examined. The results showed that the tensile strength of the film can reach to 31.24 &plusmn, 0.22 MPa when the mass ratios of CS, corn starch, and glycerin were 2.5%, 7%, and 0.5% respectively. The addition of cinnamaldehyde made the films have great inhibitory effect on Botrytis cinerea, Rhizopus, and Escherichia coli. In particular, the film had a significant fresh-keeping effect on strawberries, which reduced the loss of nutritional value, when aiming at soluble solids, titratable acid value, weight loss rate, and other indexes of strawberries. Thus, the films can slow down the physiological changes of strawberries and extend their shelf life to 11 days. Therefore, this work demonstrates the noteworthy potential of these novel films, incorporating natural antimicrobial compounds as innovative solutions to be used in active food packaging to extend the shelf-life of food products.

A facile and efficient method for direct C–H formylation of phenolated 1,4-disubstituted 1,2,3-triazoles using DMSO as the formyl source has been developed. The reaction proceeded smoothly under metal-free conditions with good functional group tolerance and high selectivity co-controlled by the triazole ring and hydroxyl group. Synopsis Direct C–H formylation of phenolated 1,4-disubstituted 1,2,3-triazoles using DMSO as the formyl source has been developed under metal-free conditions with good functional group tolerance and high selectivity.

In this study, we developed edible films designed to control the growth of Staphylococcus aureus in tryptone soya agar. We analyzed three edible film-forming substrates: sodium alginate, sodium carboxymethylcellulose, and collagen. In addition, we evaluated Lactococcus lactis, which produces bacteriocin and lactic acid. Lactococcus lactis-containing edible films were constructed via tape-casting method. Optical, mechanical, and antimicrobial properties of the edible films were measured to examine the effects of Lactococcus lactis on film matrices. Further, we determined the survival of Lactococcus lactis after the film-drying process and viability of Lactococcus lactis stored for 24 days at 4 °C. Our results indicate that incorporation of Lactococcus lactis changed the physical properties of edible films. Films containing Lactococcus lactis showed reduced gloss and transparency. There are insignificant modifications were observed in terms of tensile strength and elongation at break. At 4 °C, used to represent a low-temperature environment, the growth of Staphylococcus aureus was inhibited for 7 days in edible films populated with Lactococcus lactis. The viability of Lactococcus lactis was higher in sodium alginate/sodium carboxymethylcellulose films, and was highest in films composed of sodium alginate and methylcellulose. In summary, our study provides a new method for functional food packaging.

International audience; In this study, we developed and tested various antimicrobial polyvinyl alcohol (PVA)/tea polyphenol (TP) composite films intended to extend the shelf life of packaged strawberries. Each PVA/TP film with volumetric ratios of 10/0, 9/1, 8/2, 7/3, 6/4 and 5/5 was prepared using tap-casting methods and characterized with respect to its infrared spectrum, tensile strength, oxygen permeability, water solubility, biodegradation, and antimicrobial properties. The effects of the various composite films were subsequently evaluated based on the fruit's weight loss, decay rate, firmness, pH, titratable acidity, and soluble solids. The results indicated that thePVA/TP-8/2 composite film effectively retarded the fruit's weight and firmness loss. In addition, the PVA/TP-8/2 composite film significantly retarded the fruit's titratable acid and soluble solid loss and limited microbial proliferation. Among the various antimicrobial composite films tested, the PVA/TP-8/2 composite film exhibited significant potential as a packaging material that would extend the shelf life of strawberries.

International audience; In this study, biopolymer-based antimicrobial fibrous membranes constituted by polylactic acid (PLA) and ultrasonically dispersed ZnO nanoparticles (NPs) were developed by electrospinning. The morphology, mechanical properties, thermodynamics and antimicrobial properties of membranes with different ZnO NPs content were comprehensively studied. The results showed that the best performance was achieved when the content of ZnO content was 0.5 wt% (PLA/ZnO-0.5%). Specifically, the tensile strength and elongation at break of the composite membrane were 6.85 ± 0.19 MPa and 74.90 ± 0.59%, respectively, and the inhibition zones of Escherichia coli and Staphylococcus aureus were 15.02 ± 0.18 mm and 14.74 ± 0.06 mm, respectively. In addition, an appropriate ultrasonication time of 45 min improved the thermal, ultraviolet (UV) barrier, and antibacterial properties of the composite membrane. At the 45 min ultrasonication time, the inhibition zone of PLA/ZnO-0.5% against Escherichia coli and Staphylococcus aureus was 18.11 ± 0.15 mm and 15.80 ± 0.11 mm, respectively. Therefore, PLA/ZnO-0.5% can be applied in food packaging to provide an antibacterial effect and UV light barrier.

A facile and efficient method for the regioselective acylation of 1,4-disubstituted 1,2,3-triazoles by using a Pd-catalyzed C–H bond-activation strategy with tert-butyl hydroperoxide (TBHP) as an oxidant and an aromatic aldehyde as the acyl source has been developed. This synthetic approach was applied to a wide range of substrates to generate various 1,2,3-triazole derivatives that contain the diaryl ketone scaffold.

Many conductive scaffolds were fabricated to mimic the topography of the cardiac microenvironment in vitro in order to improve the performance of engineered cardiac tissues. This study fabricated aligned poly(lactic-co-glycolic acid)/multiwalled carbon nanotube fibers by electrospinning. The Young's modulus and conductivity were significantly greater on poly(lactic-co-glycolic acid) fibers with 3% multiwalled carbon nanotubes compared to others. Topographical cues and conductivity were applied to investigate the combined effect on cardiomyocyte behavior. Neonatal rat cardiomyocytes cultured on the conductive fibers maintained their viability, induced cell elongation, and enhanced sarcomeric α-actinin and troponin I production in cardiomyocytes. The results indicate that poly(lactic-co-glycolic acid)/multiwalled carbon nanotube composite fibers have great potential for cardiac tissue engineering.

The objective of this study was to determine the impact of wheat bran and its main polysaccharides on intestinal bacteria and gene expression of intestinal barrier function relevant proteins. Thirty freshly weaned male piglets were assigned randomly to five dietary treatment groups with six piglets per group. Accordingly, five synthetic diets including a basal control diet without fiber components (CON), wheat bran diet (10% wheat bran, WB), arabinoxylan diet (AX), cellulose diet (CEL) and combined diet of arabinoxylan and cellulose (CB) were studied. The piglets were fed ad libitum for 30 d. Lower Escherichia coli (E. coli) populations in WB group and higher probiotic (Lactobacillus and Bifidobacterium) populations in groups fed diets containing arabinoxylan (WB, AX and CB) were observed and compared with CON group. Compared with CON group, the gene expressions of cystic fibrosis transmembrane conductance regulator (CFTR), calcium-activated chloride channel regulator 1 (CLCA1) and voltage-gated chloride channel 2 (CIC2) were suppressed in the WB group. And wheat bran down-regulated gene expression of pro-inflammation (TNF-α, IL-1β, IL-6) and TLRs/MyD88/NF-κB pathway compared with CON group. In conclusion, wheat bran and its main polysaccharides could change intestinal microflora and down-regulate the gene expression of intestinal barrier function relevant proteins in the distal small intestinal mucosa.

Graphical abstract, Highlights • PVA/AgNPs nanofibers were grafted with 3,3′,4,4′-benzophenone tetracarboxylic acid. • The water vapor transmittance and mechanical properties were improved. • It retained >70% of its original OH⋅ radical and H2O2 charging capacity after 7 cycles. • It showed higher filtration efficiency and antibacterial activity., In this study, poly(vinyl alcohol) (PVA) membranes containing Ag nanoparticles (AgNPs) were prepared by electrospinning and grafted copolymerization with 3,3′,4,4′-benzophenone tetracarboxylic acid (BPTA) to provide better mechanical properties, lower water vapor transmittance, and higher antibacterial activity (against Staphylococcus aureus and Escherichia coli) than the PVA/AgNPs membrane. The PVA/AgNPs/BPTA membrane showed higher antibacterial activity than the other membranes, and it produced inhibition zones with diameters of 18.12 ± 0.08 and 16.41 ± 0.05 mm against S. aureus and E. coli, respectively. The PVA/AgNPs/BPTA membrane was found to be capable of promoting reactive oxygen species (ROS) formation under both light and dark conditions. Cycling experiments performed following ROS quenching showed that the best-performing composite membrane retained >70% of its original OH⋅ radical and H2O2 charging capacity after seven cycles. In the filtration test, the electrospun nanofibrous membranes showed high filtration efficiencies of 99.98% for sodium chloride (NaCl). In addition, these membranes maintained a relatively low pressure drop of 168 Pa with a basis weight of 2.1 g m−2. Thus, the PVA/AgNPs/BPTA membrane was concluded to be a promising medical protective material offering the benefits of structural stability and reusability.

In this study, two different species of lactic acid bacteria (LAB) (Lactobacillus plantarum and Pedocococcus pentosaceus) with high exopolysaccharide (EPS) yield were selected from a pickled water. Further, edible films based on cassava starch (CS) were developed containing LAB, and sodium carboxymethylcellulose (CMC). After addition of probiotics, the antioxidant activity of the composite film was significantly enhanced. Further, as the probiotic content increased, the antioxidant activity continuously increased. Moreover, L. plantarum showed uniform distribution in the CS/CMC matrix, forming a denser structure, which effectively blocked the penetration of water molecules and exhibited ultraviolet protection. Finally, due to the intermolecular interaction between probiotics and the CS/CMC matrix, the water vapor and light transmission rates were reduced, effectively blocking water and light to prevent lipid oxidation deterioration in food packaging. Banana shelf life has qualitatively improved with 2% LAB added composite film and its application in food packaging has been affirmed.

In this study, secondary pyrolysis oil-based drilling cuttings ash (OBDCA-sp) was used to remediate chromium (Cr)-contaminated soil. The effects of the OBCDA-sp mesh, OBCDA-sp dosage and soil moisture content on the removal of Cr (VI) were investigated. Subsequently, a kinetic experiment was conducted where the pseudo-first-order and pseudo-second-order kinetic models both fitted well on OBDCA-sp with the adsorption process of Cr (VI) in soil. The change of the chromium form indicated that the addition of OBCDA-sp transformed Cr from an effective state to a stable form, reducing its mobility and bioavailability. X-ray diffraction and Fourier transform infrared spectroscopy analysis were used to verify the potential mechanism of Cr (VI) removal; Ba, Fe, S, and P elements in OBCDA-sp were observed to play a significant role in the reduction of Cr (VI). The results from this study indicate that OBCDA-sp could be an emergent and promising alternative for the remediation of Cr-contaminated soil.

An antibacterial and anti-oxidation composite film was prepared by a casting method using sodium alginate (SA) and apple polyphenols (APPs) as the base material and glycerol as the plasticizer. Silver nanoparticles (AgNPs) were deposited by ultrasonic-assisted electrospray method. The degree of influence of the addition ratio of SA and AgNPs and different ultrasonic time on the mechanical properties, barrier properties, optical properties, and hydrophilicity of the composite film was explored. The composite films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the SA: AgNPs ratio of 7:3 and the ultrasonic time for 30 min have the best comprehensive performance, and SA/AgNPs/APP films showed the lowest water vapor permeability value of 0.75 &times, 10&minus, 11 g/m&middot, s&middot, Pa. The composite film has good strength and softness, with tensile strength (TS) and elongation at break (E) at 23.94 MPa and 29.18%, respectively. SEM images showed that the surface of the composite film was smooth and the AgNPs&rsquo, distribution was uniform. The composite film showed broad antibacterial activity, and the antibacterial activity of Escherichia coli (92.01%) was higher than that of Staphylococcus aureus (91.26%). However, due to the addition of APP, its antioxidant activity can reach 98.39%, which has a synergistic effect on antibacterial activity. For strawberry as a model, the results showed that this composite film can prolong the shelf life of strawberries for about 8 days at 4 &deg, C, effectively maintaining their storage quality. Compared with the commonly used PE(Polyethylene film) film on the market, it has a greater fresh-keeping effect and can be used as an active food packaging material.

Response Surface Methodology (RSM) was used to assess the optimal conditions for a Water/Oil/Water (W/O/W) emulsion for encapsulated nisin (EN). Nano-encapsulated nisin had high encapsulation efficiencies (EE) (86.66 &plusmn, 1.59%), small particle size (320 &plusmn, 20 nm), and low polydispersity index (0.27). Biodegradable polyvinyl alcohol (PVA) and polyacrylate sodium (PAAS) were blended with EN and prepared by electrospinning. Scanning electron microscopy (SEM) revealed PVA/PAAS/EN nanofibers with good morphology, and that their EN activity and mechanical properties were enhanced. When the ultrasonication time was 15 min and 15% EN was added, the nanofibers had optimal mechanical, light transmittance, and barrier properties. Besides, the release behavior of nisin from the nanofibers fit the Korsemeyer&ndash, Peppas (KP) model, a maximum nisin release rate of 85.28 &plusmn, 2.38% was achieved over 16 days. At 4 &deg, C, the growth of Escherichia coli and Staphylococcus aureus was inhibited for 16 days in nanofibers under different ultrasonic times. The application of the fiber in food packaging can effectively inhibit the activity of food microorganisms and prolong the shelf life of strawberries, displaying a great potential application for food preservation.

Mesenchymal stem cells (MSCs) have been widely used for regenerative therapy. In most current clinical applications, MSCs are delivered by injection but face significant issues with cell viability and penetration into the target tissue due to a limited migration capacity. Some therapies have attempted to improve MSC stability by their encapsulation within biomaterials; however, these treatments still require an enormous number of cells to achieve therapeutic efficacy due to low efficiency. Additionally, while local injection allows for targeted delivery, injections with conventional syringes are highly invasive. Due to the challenges associated with stem cell delivery, a local and minimally invasive approach with high efficiency and improved cell viability is highly desired. In this study, we present a detachable hybrid microneedle depot (d-HMND) for cell delivery. Our system consists of an array of microneedles with an outer poly(lactic-co-glycolic) acid (PLGA) shell and an internal gelatin methacryloyl (GelMA)-MSC mixture (GMM). The GMM was characterized and optimized for cell viability and mechanical strength of the d-HMND required to penetrate mouse skin tissue was also determined. MSC viability and function within the d-HMND was characterized in vitro and the regenerative efficacy of the d-HMND was demonstrated in vivo using a mouse skin wound model.