Manuka honey (MH) is used as an antibacterial agent in bioactive wound dressings via direct impregnation onto a suitable substrate. MH provides unique antibacterial activity when compared with conventional honeys, owing partly to one of its constituents, methylglyoxal (MGO). Aiming to investigate an antibiotic-free antimicrobial strategy, we studied the antibacterial activity of both MH and MGO (at equivalent MGO concentrations) when applied as a physical coating to a nonwoven fabric wound dressing. When physically coated on to a cellulosic hydroentangled nonwoven fabric, it was found that concentrations of 0.0054 mg cm⁻² of MGO in the form of MH and MGO were sufficient to achieve a 100 colony forming unit % bacteria reduction against gram-positive Staphylococcus aureus and gram-negative Klebsiella pneumoniae, based on BS EN ISO 20743:2007. A 3- to 20-fold increase in MGO concentration (0.0170–0.1 mg cm⁻²) was required to facilitate a good antibacterial effect (based on BS EN ISO 20645:2004) in terms of zone of inhibition and lack of growth under the sample. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was also assessed for MGO in liquid form against three prevalent wound and healthcare-associated pathogens, i.e., Staphylococcus aureus, gram-negative Pseudomonas aeruginosa and gram-positive Enterococcus faecalis. Other than the case of MGO-containing fabrics, solutions with much higher MGO concentrations (128 mg L⁻¹–1024 mg L⁻¹) were required to provide either a bacteriostatic or bactericidal effect. The results presented in this study therefore demonstrate the relevance of an MGO-based coating as an environmentally friendly strategy for the design of functional dressings with antibiotic-free antimicrobial chemistries.

This article compares the dyeing of cellulose diacetate (cellulose‐based) and polyester fabrics using supercritical carbon dioxide (SC‐CO₂) and aqueous media. The benefits of dyeing in SC‐CO₂ were clearly demonstrated in laboratory‐based and pilot‐scale studies in terms of increased colour strength, uniformity, fastness and the absence of auxiliaries such as dispersing agents or surfactants. In addition, the “super‐levelling” nature of the SC‐CO₂ medium was demonstrated in the reprocessing of polyester “waste textile” and the re‐use of the “locked‐in waste” colourant. The SC‐CO₂ processing medium can be utilised to accurately colour “multiple life” polyester and cellulose acetate uniformly and to creatively tie‐dye polyester and cellulose acetate fabrics. Through SC‐CO₂ fluid technology, we can envisage a viable waterless circular manufacturing and recycling/remanufacturing framework for the predominantly polyester global fibre market coupled to the sustainably sourced, biodegradable cellulose diacetate as a replacement for cotton. The key technical and commercial advantages being the use of a single solvent dye class for both polyester and the cellulose diacetate, saving on energy costs, integrated simpler processing, reduced water usage and associated efficient recycling. Further, repositioning the cellulosic fibre industry towards using sustainable forests is attractive in terms of improved land, water and environmental management.

Previous studies have established that the application of crosslinking dyes and easy care finishes to cotton can significantly reduce the dissolution of waste cotton in swelling solvents and limit potential recycling of cellulosic materials through Lyocell fibre regeneration process. In this study, a sequential hydrolysis/reduction/oxidative treatment was investigated as a potential method to completely strip all types of reactive dye chromophores from cotton. It was established that the treatment could completely strip off colours from the reactively dyed fabrics and post-consumer denim jeans fabric resulting in a white, NMMO-dissolvable cellulosic material, which could be used as a feedstock for Lyocell fibre regeneration. The white cellulose had an acceptable degree of polymerisation and the regenerated fibres had structural and mechanical properties similar to those of fibres regenerated from conventional wood pulp. Blending conventional wood pulp and recycled cotton pulp allowed manufacturing of regenerated Lyocell-type fibres with acceptable properties.

Healthcare associated infections (HCAIs) are responsible for substantial patient morbidity, mortality and economic cost. Infection control strategies for reducing rates of transmission include the use of nonwoven wipes to remove pathogenic bacteria from frequently touched surfaces. Wiping is a dynamic process that involves physicochemical mechanisms to detach and transfer bacteria to fibre surfaces within the wipe. The purpose of this study was to determine the extent to which systematic changes in fibre surface energy and nano-roughness influence removal of bacteria from an abiotic polymer surface in dry wiping conditions, without liquid detergents or disinfectants. Nonwoven wipe substrates composed of two commonly used fibre types, lyocell (cellulosic) and polypropylene, with different surface energies and nano-roughnesses, were manufactured using pilot-scale nonwoven facilities to produce samples of comparable structure and dimensional properties. The surface energy and nano-roughness of some lyocell substrates were further adjusted by either oxygen (O₂) or hexafluoroethane (C₂F₆) gas plasma treatment. Static adpression wiping of an inoculated surface under dry conditions produced removal efficiencies of between 9.4% and 15.7%, with no significant difference (p < 0.05) in the relative removal efficiencies of Escherichia coli, Staphylococcus aureus or Enterococcus faecalis. However, dynamic wiping markedly increased peak wiping efficiencies to over 50%, with a minimum increase in removal efficiency of 12.5% and a maximum increase in removal efficiency of 37.9% (all significant at p < 0.05) compared with static wiping, depending on fibre type and bacterium. In dry, dynamic wiping conditions, nonwoven wipe substrates with a surface energy closest to that of the contaminated surface produced the highest E. coli removal efficiency, while the associated increase in fibre nano-roughness abrogated this trend with S. aureus and E. faecalis. Plasma modification of the nano-roughness and surface energy of fibres in nonwoven wipes was found to influence the relative removal efficiencies of common bacterial pathogens from model healthcare surfaces under dynamic wiping conditions.