At present, there is an urgent need in medicine and industry to develop new approaches to eliminate bacterial biofilms. Considering the low efficiency of classical approaches to biofilm eradication and the growing problem of antibiotic resistance, the introduction of nanomaterials may be a promising solution. Outstanding antimicrobial properties have been demonstrated by nanoparticles (NPs) of metal oxides and their nanocomposites. The review presents a comparative analysis of antibiofilm properties of various metal oxide NPs (primarily, CuO, Fe3O4, TiO2, ZnO, MgO, and Al2O3 NPs) and nanocomposites, as well as mechanisms of their effect on plankton bacteria cells and biofilms. The potential mutagenicity of metal oxide NPs and safety problems of their wide application are also discussed.

Advanced wound dressings improve wound healing by releasing antibacterial agents, accelerating wound closure, and reporting (sensing) changes in the wound’s state. The challenge with the release of antibacterial agents such as drugs, peptides, or nanoparticles is their unregulated administration. In addition, bacteria resistance to antibiotics stimulates the search for new types of antibacterial wound dressings. Here, we report a new approach to antibacterial wound dressings by utilizing a nanocolloidal hydrogel with strong Fe3+ ion sequestration capability, thus depriving bacteria of much-needed ionic iron and suppressing bacteria growth. The hydrogel was derived from cellulose nanocrystals decorated with carbon dots (C-dot/CNCs). Upon Fe3+ ion uptake by the nanofibrillar hydrogel, the photoluminescence of the hydrogel was quenched, due to adsorption of ions to the C-dot surface, thus reporting on the removal of ionic iron from the medium. The hydrogel suppressed the growth of antibiotic-resistant Gram-negative Escherichia coli, antibiotic-resistant Pseudomonas aeruginosa, and Gram-positive Staphylococcus aureus and was noncytotoxic for human fibroblasts. Wound dressings were readily fabricated using three-dimensional (3D) printing. The new mechanism of antibacterial performance of the hydrogel, its sensing capability, biocompatibility, and the capability to 3D print wound dressing patches make it a very promising material for the fabrication of advanced wound dressings.

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Rapid detection of bacterial contamination is an essential task in numerous medical and technical processes and one of the most rapidly developing areas of nano-based analytics. Here, we present a simple-to-use and special-equipment-free test-system for bacteria detection based on magnetite nanoparticle arrays. The system is based on peroxide oxidation of chromogenic substrate catalyzed by magnetite nanoparticles, and the process undergoes computer-aided visual analysis. The nanoparticles used had a pristine surface free of adsorbed molecules and demonstrated high catalytic activities up to 6585 U/mg. The catalytic process showed the Michaelis–Menten kinetic with Km valued 1.22 mmol/L and Vmax of 4.39 µmol/s. The nanoparticles synthesized were used for the creation of inkjet printing inks and the design of sensor arrays by soft lithography. The printed sensors require no special equipment for data reading and showed a linear response for the detection of model bacteria in the range of 104–108 colony-forming units (CFU) per milliliter with the detection limit of 3.2 × 103 CFU/mL.

Organically-coated nanomaterials are intensively studied and find numerous applications in a wide range of areas from optics to biomedicine. One of the recent trends in material science is the application of bio-mimetic polydopamine coatings that can be produced on a variety of substrates in a cost-efficient way under mild conditions. Such coatings not only modify the biocompatibility of the material but also add functional amino groups to the surface that can be further modified by classic conjugation techniques. Here we show an alternative strategy for substrates modification using dopamine conjugates instead of native dopamine. Compared to the classic scheme, the proposed strategy allows separation of the “organic” and “colloidal” stages, and simplified identification and purification steps. Modification with pre-modified dopamine made it possible to achieve high loading capacities with active components up to 10.5% wt. A series of organo-inorganic hybrids were synthesized and their bioactivity was analyzed.