The inappropriate use of antimicrobials has resulted in the selection of resistant strains. Thus, a great number of studies have focused on the investigation of new antimicrobial agents. The use of zinc oxide nanoparticles (ZnO NPs) to optimise the fight against microbial resistance has been receiving increased attention due to the non-specific activity of inorganic antimicrobial agents. The small particle size and the high surface area of ZnO NPs can enhance antimicrobial activity, causing an improvement in surface reactivity. In addition, surface modifiers covering ZnO NPs can play a role in mediating antimicrobial activity since the surface properties of nanomaterials alter their interactions with cells; this may interfere with the antimicrobial effect of ZnO NPs. The possibility of using surface modifiers with groups toxic to microorganisms can improve the antimicrobial activity of ZnO NPs. Understanding the exact toxicity mechanisms is crucial to elucidating the antimicrobial activity of ZnO NPs in bacteria and fungi. Therefore, this review aims to describe the mechanisms of ZnO NPs toxicity against fungi and bacteria and how the different structural and physical-chemical characteristics of ZnO NPs can interfere in their antimicrobial activity.

Pharmaceutical design has enabled important advances in the prevention, treatment, and diagnosis of diseases. The use of nanotechnology to optimize the delivery of drugs and diagnostic molecules is increasingly receiving attention due to the enhanced efficiency provided by these systems. Understanding the structures of nanocarriers is crucial in elucidating their physical and chemical properties, which greatly influence their behavior in the body at both the molecular and systemic levels. This review was conducted to describe the principles and characteristics of techniques commonly used to elucidate the structures of nanocarriers, with consideration of their size, morphology, surface charge, porosity, crystalline arrangement, and phase. These techniques include X-ray diffraction, small-angle X-ray scattering, dynamic light scattering, zeta potential, polarized light microscopy, transmission electron microscopy, scanning electron microcopy, and porosimetry. Moreover, we describe some of the commonly used nanocarriers (liquid crystals, metal–organic frameworks, silica nanospheres, liposomes, solid lipid nanoparticles, and micelles) and the main aspects of their structures.

Dyeing processes are highly important for differentiation of textile products, and in general, they use a huge amount of water and chemical additives, generating a great environmental impact. In the last years, the interest in finding alternative environmentally friendly solvents for these processes has increased, with a double aim: to decrease the quantity of water used and to improve the dyeing quality. In this work, we analyze an alternative procedure to dye cotton fabrics with only two dyeing agents, a polyfunctional reactive dye and a protic ionic liquid (PIL) as an alternative solvent, avoiding the need for common chemical additives into the conventional process, thus reducing the amount and concentration of pollutants. The proposed procedure allows PIL recycling with no appreciable loss of efficiency, since after dyeing, the unfixed dye remains active in the bath, following the known exhaustion dyeing method. A collection of 13 PILs were studied with the aim of analyzing their effectiveness as dyeing solvents in terms of different standard dyeing quality parameters such as absorption color, tensile strength, and surface morphology of the cotton dyed. The results obtained using PIL as dyeing solvents in the absence of any auxiliary agent showed an outstanding effect when compared with the aqueous process under the same operational conditions.

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