The textile industry’s reliance on synthetic dyes contributes significantly to pollution, highlighting the need for sustainable alternatives like biopigments. This study investigates the production and application of the biopigment prodigiosin, which was produced by Pseudomonas putida with a yield of 1.85 g/L. Prodigiosin was prepared under acidic, neutral, and alkaline conditions, resulting in varying protonation states that influenced its affinity for cotton and polyester fibers. Three surfactants (anionic, cationic, non-ionic) were tested, with non-ionic Tween 80 yielding a promising color strength (above 4) and fastness results with neutral prodigiosin at 1.3 g/L. Cotton and polyester demonstrated good washing (color difference up to 14 for cotton, 5 for polyester) and light fastness (up to 15 for cotton, 16 for polyester). Cellulose acetate, used in the conventional printing process as a thickener, produced superior color properties compared to commercial thickeners. Neutral prodigiosin achieved higher color strength, and cotton fabrics displayed halochromic properties, distinguishing them from polyester, which showed excellent fastness. Prodigiosin-printed samples also exhibited strong antimicrobial activity against Pseudomonas aeruginosa and retained halochromic properties over 10 pH cycles. These findings suggest prodigiosin as a sustainable dye alternative and pH sensor, with potential applications in biomedical materials, such as antimicrobial and pH-responsive wound dressings.

[Excerpt] This research envisages the use of bacterial nanocellulose (BNC) as a biomaterial for implants to mitigate neuralgias, focusing on the material's inherent limitations. BNC is widely valued for its excellent mechanical properties, ease of modification, and non-anthropogenic degradability [1]. However, its absent electrical conductivity, insufficient antimicrobial activity, and weak interaction with neural tissues restrict its application as a neural implant [2-4]. To overcome these challenges, lignin/glycerine was incorporated into BNC, and a dielectric barrier discharge (DBD) plasma surface treatment was applied to enhance biocompatibility and improve integration with neural tissues. Plasma treatment is known to modify surface characteristics, namely hydrophilicity and protein adsorption, facilitating cell adhesion and reducing immune response [5]. [...]

This work aimed at studying the dyeing of cotton fabrics with madder extract using two biomordants, quebracho tree extract (Schinopsis spp.) and laccase. Pre-treatment with quebracho increased the colour strength, washing and UV light fastness, and UV protection, while laccase only shows an increase in the UV light fastness. The application of biomordants together with the metal ones (aluminium or iron salts) led to an improved UV light fastness compared to the samples mordanted only with metal salts. Meanwhile, although the colour strength was lower than in the metal-mordanted samples, greater UV protection factors were obtained in the samples pre-treated with quebracho or laccase and iron salt.

[Excerpt] Digital printing is one of the most interesting advances in the textile sector. Digital textile printing can create an infinite number of colors as well as excellent print fastness. One of the most important components of ink-jet printing technology is the ink, which influences the printing quality and reliability. The general requirements for inks used in textile digital printing are purity, particle size (in the case of pigment inks), viscosity, surface tension, stability, pH value, and conductivity.

To achieve good colour depth and fastness of naturally dyed fabrics is necessary to use mordants, usually metallic salts, which are potentially harmful to the environment and human health. In this work, the effect of plasma and cationization pre-treatments on cotton fabrics dyed with natural dye madder extract was investigated as environmentally sustainable alternative processes. Air atmospheric dielectric barrier discharge (DBD) plasma treatment showed a slight improvement in fastness to washing and UV light when samples were dyed at pH 11. On the other side, cationization with poly(diallyldimethylammonium chloride) (PDDA) greatly improved the dye uptake onto cotton, but with poor fastness. Meanwhile, the simultaneous pre-treatment with metallic mordants improved significantly the fastness properties, being the PDDA/Fe pre-treatment, followed by dyeing at pH 5, the process which showed the best results regarding colour strength, fastness to UV light, and UV protection.

Children’s skin is highly sensitive and prone to irritation, allergies, and infections, requiring special consideration in textile selection. Although clothing serves as a protective barrier, it can also pose a risk when dyed with toxic chemical colourants. This study explores the potential of multifunctional natural dyes as safer alternatives for children’s clothing, particularly for those with dermatological conditions. Cotton knitted fabrics were dyed through exhaustion with extracts of madder root (Rubia tinctorum L.), pomegranate peel (Ppe, Punica granatum L.), oxidised logwood (Logox, Haematoxylum campechianum L.), and tannin from quebracho (Schinopsis lorentzii Griseb.), both individually and in various combinations with or without potassium aluminium sulphate dodecahydrate (alum). The combination of madder and Ppe demonstrated the most promising multifunctional performance, being classified as a weak disinfectant against S. aureus (3.7 log reduction) and showing the highest antioxidant activity (92.6 ± 2.56% 2,2′ -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical reduction), while maintaining excellent results after washing. Moreover, these natural formulations expanded the achievable colour palette from each dye while maintaining moderate wash fastness. The results highlight the relevance of these findings to textile and fashion designers, offering sustainable tools for creating health conscious, visually appealing garments. This research reinforces the potential of natural dyes and biomordants in developing functional textiles that support children’s wellbeing and environmental responsibility.

Hospitals and nursing home wards are areas prone to the propagation of infections and are of particular concern regarding the spreading of dangerous viruses and multidrug-resistant bacteria (MDRB). MDRB infections comprise approximately 20% of cases in hospitals and nursing homes. Healthcare textiles, such as blankets, are ubiquitous in hospitals and nursing home wards and may be easily shared between patients/users without an adequate pre-cleaning process. Therefore, functionalizing these textiles with antimicrobial properties may considerably reduce the microbial load and prevent the propagation of infections, including MDRB. Blankets are mainly comprised of knitted cotton (CO), polyester (PES), and cotton-polyester (CO–PES). These fabrics were functionalized with novel gold-hydroxyapatite nanoparticles (AuNPs-HAp) that possess antimicrobial properties, due to the presence of the AuNPs’ amine and carboxyl groups, and low propensity to display toxicity. For optimal functionalization of the knitted fabrics, two pre-treatments, four different surfactants, and two incorporation processes were evaluated. Furthermore, exhaustion parameters (time and temperature) were subjected to a design of experiments (DoE) optimization. The concentration of AuNPs-HAp in the fabrics and their washing fastness were critical factors assessed through color difference (∆E). The best performing knitted fabric was half bleached CO, functionalized using a surfactant combination of Imerol® Jet-B (surfactant A) and Luprintol® Emulsifier PE New (surfactant D) through exhaustion at 70 ◦C for 10 min. This knitted CO displayed antibacterial properties even after 20 washing cycles, showing its potential to be used in comfort textiles within healthcare environments.