Microfluidic-blow-spinning of carvacrol-loaded porphyrin metal - organic framework nanofiber films with synergistic antibacterial capabilities for food packaging.

The adherence of foodborne microorganisms threatens human health, necessitating the development of antibacterial food packaging films. In this study, the antibacterial agent carvacrol (CV), hindered by its high volatility and intense aromatic odor, was encapsulated within the photosensitive metal-organic frameworks (MOFs) material PCN-224 (loading rate 50%). Subsequently, the microfluidic-blow-spinning (MBS) technique was employed for the rapid fabrication of CV@PCN-224/polycaprolactone (PCL)/chitosan (CS) nanofiber films. The incorporation of CV@PCN-224 NPs enhances the nanofiber films' thermal stability and mechanical properties and improves the water vapor permeability while maintaining the sustained release of CV over an extended period and good biocompatibility. Due to the simultaneous loading of antibacterial agent (CV) and photosensitive agent (PCN-224), the CV@PCN-224/PCL/CS films exhibited good synergistic antibacterial functionality, as demonstrated by effective inhibition against both E. coli and S. aureus. All results show the vast potential of the prepared nanofiber films in antibacterial food packaging.

Preparation of amphiphilic polyquaternium nanofiber films with antibacterial activity via environmentally friendly microfluidic-blow-spinning for green food packaging applications.

Green food packaging plays an important role in environmental protection and sustainable development. Therefore, it is advisable to employ low-energy consumption manufacturing techniques, select environmentally friendly materials, and focus on cost-effectiveness with high production yields during the production process. In this study, an amphiphilic polyquaternium called PBzCl was proposed and synthesized by free radical polymerization of cost-efficient quaternary ammonium salts and methacrylate monomers. Then, biodegradable PCL and PVP were used to rapidly prepare the PBzCl@PCL/PVP nanofiber films via environmentally friendly microfluidic-blow-spinning (MBS). The best antibacterial effect was observed at a PBzCl loading concentration of 13.5%, and the PBzCl@PCL/PVP nanofiber films had 91% and 100% antibacterial rates against Escherichia coli and Staphylococcus aureus, respectively. Besides, the loading of PBzCl improved the water stability of the PCL/PVP nanofiber films, and the films also showed excellent biocompatibility. Overall, PBzCl@PCL/PVP nanofibre films have promising food packaging potential.

Fabrication of antimicrobial PCL/EC nanofibrous films containing natamycin and trans-cinnamic acid by microfluidic blow spinning for fruit preservation.

Fruit is susceptible to various postharvest pathogens; thus, the development of multifunctional preservation materials that can achieve the broad-spectrum inhibition of different pathogens is a current research hotspot. Here, microfluidic blow spinning was used to create a biodegradable polycaprolactone/ethyl cellulose (PCL/EC) nanofibrous film that incorporated two naturally-sourced compounds, natamycin and trans-cinnamic acid, resulting in multi-microbial inhibition. The PCL/EC-based film had a smooth and even morphology, indicating the favorable integration of PCL and EC. After the incorporation of ingredients, the film exhibited good inhibitory activity against Escherichia coli, Staphylococcus aureus, and Botrytis cinerea, and it had finer fiber diameters, higher permeability, and antioxidant properties. We further demonstrated that strawberries that were padded with the film had good resistance to Botrytis cinerea. Also, the film did not interference with the qualities of the strawberries during storage. The study demonstrates a promising application for multi-antimicrobial and bio-friendly packaging materials in postharvest fruit preservation.

Characterization of glycosylated gelatin/pullulan nanofibers fabricated by multi-fluid mixing solution blow spinning.

In this work, multi-fluid mixing solution blow spinning was applied to develop gelatin/pullulan composite nanofibers, and then the nanofibers were glycated to enhance the physical properties. The results show that the grafting degree of the nanofibers increased significantly from 17.5 % to 36.0 % as the glycation time increased, and the morphology results indicated that 72 h of glycation did not destroy the structure of the nanofibers. FTIR results show that the glycation consumed the the-NH2 groups, cleaved sugar units of polysaccharide, and affected the secondary structure of the protein. The glycation enhanced the thermal stability and improved the rigidity of the nanofibers. Besides, after 120 h of glycation, the water contact angle of nanofibers increased from 0° to 79.1°, and the water vapor transmission rates decreased from 12.49 to 8.97 g mm/m2 h kPa, indicating the enhanced hydrophobicity and barrier properties. In addition, the glycation improved the water stability of the nanofibers, which increased the applicability of the gelatin/pullulan nanofibers in food packaging. The present work provides a green and efficient method for improving the physical properties of gelatin/pullulan nanofibers.

Formononetin/methyl-ß-cyclodextrin inclusion complex incorporated into electrospun polyvinyl-alcohol nanofibers: Enhanced water solubility and oral fast-dissolving property.

Improving solubility and administration route of isoflavone formononetin (FMN) are critical factors to improve its bioavailability in the oral cavity. This study fabricated fast-dissolving nanofibers containing FMN/methyl-ß-cyclodextrin (FMN/Me-ß-CD) inclusion complex. The solubility of FMN could be increased by approximately 50 times at 20 mM aqueous Me-ß-CD. Interactions and thermodynamic parameters of the host-guest inclusion complex were studied by a fluorescence quenching method. The structure and mechanisms of the complex were further studied by molecular docking and molecular dynamics. Finally, polyvinyl-alcohol (PVA) nanofibrous webs containing the FMN/Me-ß-CD inclusion complex were fabricated by electrospinning. The dissolution test demonstrated that the FMN/Me-ß-CD/PVA nanofibers can be dissolved in artificial saliva within approximately 2 s. This study shows the potential of Me-ß-CD inclusion and electrospinning to improve solubility and administration route of isoflavones.