Aged-look vat dyed cotton with anti-bacterial/anti-fungal properties by treatment with nano clay and enzymes

Chitosan Nanoparticles as Bioactive Vehicles for Textile Dyeing: A Proof of Concept

In recent years bioactive textiles have risen to the forefront of consumers perception due to their potential protection against virus, fungi and bacteria. However, traditional textile staining is an eco-damaging process that and current methods of textile functionalization are expensive, complicated and with great environmental impact. With that in mind, this work sought to show a possible solution for this problematic through the usage of a novel one step textile dyeing and functionalization method based upon nanoencapsulated textile dyes (NTDs). To do so navy blue everzol NTDs were produced with chitosan, cotton dyed, characterized through FTIR and SEM and biological potential evaluated through biocompatibility screening and antimicrobial activity against skin pathogens. The data obtained showed that NTDs effectively dyed the target textile through a coating of the cotton fibre and that NTDs formed hydrogen bonds with the cellulose fibre via electrostatic interactions of the chitosan amino groups with cotton sulphate groups. From a biocompatibility perspective NTDs dyed cotton had no deleterious effects upon a skin cell line, as it promoted cellular metabolism of HaCat cells, while traditionally died cotton reduced it by 10%. Last but not least, NTDs dyed cotton showed significant antimicrobial activity as it reduced viable counts of MRSA, MSSA and A. baumannii between 1 and 2 log of CFU while traditional dyed cotton had no antimicrobial activity. Considering these results the novel method proposed shows is a viable and ecological alternative for the development of antimicrobial textiles with potential biomedical applications.

New Laccase-Mediated System Utilized for Bio-Discoloration of Indigo-Dyed Denim Fabrics

In this study, indigo-dyed denim fabric was decolorized via separate and simultaneous applying of laccase, sodium hydrosulfite, and cellulase. In this regard, the surface reflectance and color coordinates of the discolored fabrics were evaluated and scanning electron microscopy (SEM) images of the cellulase treated fabric were prepared to analyze their surfaces. Finally, the characterization of the treated samples was investigated, including moisture content, crease recovery angle, air permeability, and abrasion resistance. The color experiments showed that simultaneous applying of laccase, sodium hydrosulfite, and cellulose had a 55.79% improvement in the samples' lightness (L*). Furthermore, the color coordinate test of specimens revealed that the hue of the treated samples was changed to blue and green, and the purity of color (C*) was modified. The increment in the moisture content and air permeability of the treated specimens indicated that the comfort of the jeans clothing had been enhanced. As a result, sodium hydrosulfite demonstrates a high-efficiency denim discoloration in the laccase-mediated system.

Electrospinning of Scaffolds from the Polycaprolactone/Polyurethane Composite with Graphene Oxide for Skin Tissue Engineering

Creating scaffolds for skin tissue engineering remain challenging in terms of their mechanical and biological properties. In this paper, we present a study on the nanocomposite polyurethane (PU)/polycaprolactone (PCL) scaffolds with graphene oxide (GO), which were fabricated by using electrospinning method, for potential skin tissue engineering. For this, homogenous and soft PU nanofibers containing varying percent of polycaprolactone (12% and 15%) and nano GO (0.5-4%) were electrospun, respectively, and then characterized by different techniques/assays in vitro. For the scaffold characterization, scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) were used. The SEM results show the spun scaffolds have 3D porous structure (90%) with the fiber diameter increased with the GO concentration, while the FTIR results confirmed the presence of PU, PCL, and Go in the scaffolds. Also, the biocompatibility, via the cytotoxicity, of the scaffolds was examined by MTT assay with the human skin fibroblast cells, along with their wettability in terms of contact angle. Our results show that the scaffolds are biocompatible to the skin fibroblast cell, illustrating their potential use in skin tissue engineering. Also, our results illustrate that the addition of GO to the PU/PCL composite can increase the wettability (or hydrophilicity) and biocompatibility of scaffolds. Combined together, the nanocomposite PU/PCL scaffolds with GO are promising as biocompatible constructs for skin tissue engineering.

Tragacanth gum/nano silver hydrogel on cotton fabric: In-situ synthesis and antibacterial properties

This paper is mainly focused on introducing cotton fabric with hydrogel and antimicrobial properties using Tragacanth gum as a natural polymer with hydrogel properties, silver nitrate as silver precursor, citric acid as a cross-linking agent and sodium hypophosphite as catalyst. The water absorption behavior of the treated fabrics was investigated with moisture regain, water retention, drying time of wetted fabric at room condition and vertical wicking tests. Antibacterial properties of the samples were evaluated against Escherichia coli and Staphylococcous aureus. The SEM pictures confirmed formation of nano silver and hydrogel layer on the fabric surface and XRD performed the crystal and particle size of the nano silver. The chemical structure of the fabric samples was identified with FTIR spectra. The central composite design (CCD) was used for statistical modelling, evaluated effective parameters and created optimum conditions. The treated cotton fabrics showed good water absorption properties along with reasonable antibacterial effectiveness.