An enhancement on healing effect of wound dressing: Acrylic acid grafted and gamma-polyglutamic acid/chitosan immobilized polypropylene non-woven

Disposable biosensor based on ionic liquid, carbon nanofiber and poly(glutamic acid) for tyramine determination

In this study, an electrochemical biosensor based on carbon nanofibers (CNF), ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (IL), poly(glutamic acid) (PGA) and tyrosinase (Tyr) modified screen printed carbon electrode (SPE) was constructed for tyramine determination. Optimum experimental parameters such as CNF and IL amount, polymerization conditions of glutamic acid, enzyme loading, pH of test solution and operating potential were explored. The construction steps of the Tyr/PGA/CNF-IL/SPE were pursued by scanning electron microscopy and cyclic voltammetry. The Tyr/PGA/CNF-IL/SPE biosensor exhibited linear response to tyramine in the range of 2.0 × 10-7 - 4.8 × 10-5 M with a low detection limit of 9.1 × 10-8 M and sensitivity of 302.6 μA mM-1. The other advantages of Tyr/PGA/CNF-IL/SPE include its high reproducibility, good stability and anti-interference ability. The presented biosensor was also applied for tyramine determination in malt drink and pickle juice samples and mean analytical recoveries of spiked tyramine were calculated as 100.6% and 100.4% respectively.

The Influence of κ-Carrageenan-R-Phycoerythrin Hydrogel on In Vitro Wound Healing and Biological Function

Wound healing is widely recognized as a critical issue impacting the healthcare sector in numerous countries. The application of wound dressings multiple times in such instances can result in tissue damage, thereby increasing the complexity of wound healing. With the aim of tackling this necessity, in the present study, we have formulated a hydrogel using natural polysaccharide κ-carrageenan and phycobiliprotein R-phycoerythrin from Pyropia yezoensis. The formulated hydrogel κ-Carrageenan-R-Phycoerythrin (κ-CRG-R-PE) was analyzed for its antioxidant and antimicrobial activity. The wound healing potential of the κ-CRG-R-PE was evaluated in Hs27 cells by the wound scratch assay method. The hydrogel showed dose-dependent antioxidant activity and significant antimicrobial activity at 100 μg/mL concentration. κ-CRG-R-PE hydrogels promoted more rapid and complete wound closure than κ-Carrageenan (κ-CRG) hydrogel at 24 and 48 h. κ-CRG-R-PE hydrogels also filled the wound within 48 h of incubation, indicating that they positively affect fibroblast migration and wound healing.

Waterproof and Breathable Wound Dressing Composited By Expanded Polytetrafluoroethylene Backing and Hydrogel

Wound dressings with waterproof, breathable and bacterial-resistant properties are still rarely realized. In this work, a newly hydrogel-based dressing is designed with a backing of expanded polytetrafluoroethylene (ePTFE) film. The ePTFE grafting with polyvinylpyrrolidone (PVP) brush is composited with hydrogel successfully with an adhesion energy of ∼80 kJ/m² . In this resultant composite, the ePTFE backing contributes excellent breathability, water resistance and bacterial barrier property. The water vapor transmission rate of the composite is 4.83 × 10³  g/m² ·24 h, which can maintain the mosit evironment of wound and relive pain by evaporating water. Notably, it can withstand 500 mm water column for over 300 s, which is obviously better than the commonly used nonwoven fabric backing materials. It can also prevent the invasion of bacteria, because the pores of ePTFE backing are smaller than those of most common bacterial. As a result, the composite with an ePTFE film backing has a positive effect in accelerating wound healing, promoting the reconstruction of intact epidermis and reducing inflammation. This article is protected by copyright. All rights reserved.

κ-carrageenan-C-phycocyanin based smart injectable hydrogels for accelerated wound recovery and real-time monitoring

Wound healing remains a healthcare challenge in patients suffering from grave tissue damage due to burn injuries and severe medical conditions like diabetes and ischemia. A repeated wound dressing in such cases leads to tissue damage, which could further inflate the wound healing. It is also challenging to analyze the depth of wound bed in these conditions, which could affect the recovery period. To address this need, we have developed an injectable hydrogel from natural polysaccharide κ-carrageenan and a pigmented protein C-phycocyanin. C-phycocyanin has wound healing, antimicrobial, antioxidant and anti-inflammatory properties along with the In-vivo fluorescence imaging ability. Gelling property of κ-carrageenan could be utilized along with C-phycocyanin as an injectable and regenerative wound dressings matrix to monitor wound healing in real-time without upsetting the healing process. The hydrogel presented herein was built from ionic crosslinking of κ-carrageenan monomers along with C-phycocyanin, which provides an interconnected network of porous material with hydrophilic surface and mechanical stiffness. This porosity allows nutrients transportation and gaseous exchange across the wound healing site for the proliferation of various cells. Hydrogel material enhances the proliferation of dermal fibroblasts in vitro without inducing inflammation along with reducing the blood clotting time with no haemolysis. We have found that κ-carrageenan-C-phycocyanin (κ-CRG-C-Pc) hydrogel not only exhibit superior haemostatic capabilities in traumatic injury condition but also provide support for rapid wound healing. Overall, these findings demonstrate the potential of κ-carrageenan-C-phycocyanin hydrogels as a wound-healing and imaging platform towards accelerating tissue repair and real-time monitoring. STATEMENT OF SIGNIFICANCE: Blood clotting and inflammation are the most crucial stages of wound healing along with appropriate monitoring of the healing process. Thus, there is a need of system that could provide point-to-point care and monitoring in this multistage process. Here, we have introduced a self healing, injectable hydrogel system with in vivo imaging abilities from κ-carragenan and C-phycocyanin. C-phycocyanin improves the stability of κ-carragenan matrix and provide support to cellular adhesion, proliferation, and migration. Its anti-inflammatory response and rapid blood clotting ability further empower its applicability in critical medical conditions and wound recovery.

Biofunctionalization of Textile Materials.1. Biofunctionalization of Poly(Propylene) (PP) Nonwovens Fabrics by Alafosfalin

This paper presents the method of obtaining poly(propylene) (PP) nonwoven fabrics with antimicrobial properties, using Alafosfalin as the nonwoven modifying agent. Alafosfalin, namely L-alanyl-L-1-aminoethylphosphonic acid, presents representative P-terminal phosphonodipeptide, which possesses a strong, broad spectrum of antimicrobial properties. The analysis of these biofunctionalized nonwoven fabrics processed by the melt-blown technique, included: scanning electron microscopy (SEM), UV/Vis transmittance, FTIR spectrometry, and air permeability. The nonwovens were subjected to microbial activity tests against colonies of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Results indicate that the described nonwovens can be successfully used as an antibacterial material.

Surface Attachment of Natural Antimicrobial Coatings onto Conventional Polypropylene Nonwoven Fabric and Its Antimicrobial Performance Assessment

The growing number of microbial cross-contamination events necessitates the development of novel antimicrobial strategies in the food industry. In this study, a polypropylene nonwoven fabric (PPNWF) was grafted with a natural antimicrobial component, aloe emodin (AE), and its antimicrobial performance was evaluated. The grafted samples (PPNWF-g-AE) were examined using Fourier transform infrared spectroscopy and scanning electron microscopy. AE was effectively grafted onto the surface of the PPNWF through the adsorption covalent effect. Compared with nongrafted PPNWF, the antimicrobial activity of PPNWF-g-AE against Staphylococcus aureus, Escherichia coli, and Candida albicans was significantly enhanced. Scanning electron micrographs confirmed that the inhibitory mechanism of PPNWF-g-AE was the microbicidal function of the grafted AE. These findings indicate that PPNWF-g-AE has potential as an effective antimicrobial material in food applications.

Highly effective Cu/Zn-carbon micro/nanofiber-polymer nanocomposite-based wound dressing biomaterial against the P. aeruginosa multi- and extensively drug-resistant strains

Pseudomonas aeruginosa (P. aeruginosa) is the most prevalent bacteria in the infections caused by burn, surgery, and traumatic injuries. Emergence of the P. aeruginosa bacterial resistance against various clinical drugs for wound treatment is the major concern nowadays. The present study describes the synthesis of the polyvinyl alcohol (PVA) and cellulose acetate phthalate (CAP) polymeric composite film (~0.2mm thickness) reinforced with the Cu/Zn bimetal-dispersed activated carbon micro/nanofiber (ACF/CNF), as a wound dressing material. The focus is on determining the efficacy of the prepared biomaterial against the multi and extensively drug-resistant P. aeruginosa strains isolated from the burning, surgical, and traumatic injury-wounds. The primary synthesis steps for the biomaterial include the mixing of a blend of CAP powder and the asymmetrically distributed Cu/Zn bimetals in ACF/CNF, into the polymerization reaction mixture of PVA. Biochemical tests showed that the prepared composite material significantly enhanced the in-vitro blood clotting rate, platelet aggregation, and macrophage cell proliferation, indicating the suitability of the material as a fast wound healer. The antibacterial tests performed against the P. aeruginosa strains showed that the material effectively suppressed the bacterial growth, with the bimetal nanoparticles dispersed in the material serving as an antibacterial agent. The PVA/CAP polymer composite served as an encapsulating agent providing a slow release of the nanoparticles, besides increasing the hemostatic properties of the biomaterial. The ACF/CNF served as a support to the dispersed bimetal nanoparticles, which also provided a mechanical and thermal stability to the material. Experimentally demonstrated to be biocompatible, the prepared metal-carbon-polymer nanocomposite in this study is an effective dressing material for the P. aeruginosa-infected wounds.

Development of a γ-polyglutamic acid binder for cathodes with high mass fraction of sulfur

PGA binder, with a high density of electron-rich functional groups on the molecule, could suppress diffusion of polysulfides.

Cationic vinyl monomer-grafted polypropylene preparation and its use as a compatibilizer for polypropylene/poly(vinyl chloride) blends

Grafting polymerization is a valuable method for the modification of the chemical and physical properties of polymer surfaces. In this paper, the grafting of cationic vinyl monomer with quaternary ammonium groups, i.e., methacryloxyethyltrimethyl ammonium chloride (DMC), onto the isotactic polypropylene (iPP) granule was performed by the suspension solid-state grafting process. The technique offers new opportunities in modification of polyolefins, which has advantages of being solventless and having a lower process temperature. The grafted PP [PP-g-(St-co-DMC)] was systematically characterized by using various analytic tools including Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR spectra of the grafted iPP confirmed that DMC was successfully grafted onto the iPP backbone. The results of TGA and the hydrophilicity measurement indicated that the thermal stability of the grafted iPP was enhanced remarkably, and the hydrophilicity was also enhanced due to the addition of hydrophilic quaternary ammonium groups. Furthermore, the mechanical properties effect of PP-g-(St-co-DMC) on PP/poly(vinyl chloride) (PVC) blends was investigated. The measurements of tensile strength and impact strength indicated that the PP-g-(St-co-DMC) could remarkably enhance compatibility of PP/PVC blends. The tensile strength and the impact strength of PP/PVC blends with a concentration of PP-g-(St-co-DMC) at 4% (wt) increased up to 19.15% and 74.48%, respectively.

Preparation and characterization of the anti-virus and anti-bacteria composite air filter materials

The anti-virus and anti-bacteria active components were extracted from some Chinese medicine, such as the honeysuckle, forsythia and the licorice. Using a w/o/w emulsion method, the active components were fabricated to uniform particulate microcapsule with sustained-release properties. The polypropylene punched felt was finished with the finishing agent of microcapsule, nano ZnO and TiO₂ and polymer adhesive, and the composite air filter with anti-virus and anti-bacteria properties were formed, staphylococcus aureus, colibacillus and candida albicans were applied to antibacterial experiments. The results indicate that the anti-bacteria rate are all 100%, and the virus inactivation rate also reaches 100% to pandemic influenza A virus.