Cross-linked poly(vinyl alcohol)/citric acid electrospun fibers containing imidazolium ionic liquid with enhanced antiadhesive and antimicrobial properties

Surface coating nanoarchitectonics for optimizing cytocompatibility and antimicrobial activity: The impact of hyaluronic acid positioning as the outermost layer

Polyelectrolyte multilayers (PEMs) based on hyaluronic acid (HA) and poly (diallyldimethylammonium chloride) (PDDA) were deposited on oxidized polystyrene (PSox) via the layer-by-layer (LbL) method. The X-ray photoelectron spectroscopy (XPS) confirmed the PEM deposition on PSox, and atomic force microscopy (AFM) indicated that the surface roughness of PS also increased after PEM deposition. The PEMs significantly enhanced PS wettability, reducing the contact angle from 73° on PS to 24° on PDDA-terminated (PDDA/HA)2.5 PEM (2.5 bilayers, 5 layers) and 36° on HA-terminated (PDDA/HA)3 PEM (3 bilayers, 6 layers). The HA-terminated (PDDA/HA)₃ PEM demonstrated antimicrobial activity. Compared to uncoated PS surfaces, this PEM reduced the surface coverage of viable P. aeruginosa cells from 36.5 % to 3.7 % and S. aureus cells from 13.3 % to 2.5 % on uncoated PS surfaces. The antimicrobial assay following the JIS Z 2801-2010 standard demonstrated that the PDDA-terminated (PDDA/HA)2.5 PEM inhibited S. aureus growth by 48 %, compared to 32 % inhibition by the HA-terminated (PDDA/HA)3 PEM relative to the uncoated and non-oxidized polystyrene (PS) surface (control). HA-terminated PEM demonstrated lesser antimicrobial activity than PDDA-terminated PEM. However, both PEMs were cytocompatible against erythrocytes and human adipose-derived stem cells (ADSCs), indicating their potential for biomedical applications, particularly prosthetic coatings.

Designing Effective Antimicrobial Agents: Structural Insights into the Antibiofilm Activity of Ionic Liquids

Research concerning biofilm control is critical due to the pervasive and resilient nature of biofilms, which pose significant challenges across the industrial, environmental, and healthcare sectors. Traditional antimicrobial treatments are often ineffective against these robust structures. Here, we explore the antimicrobial properties of ionic liquids (ILs) and their efficacy in biofilm disruption. By examining the structural variations of ILs, we highlight the key role of hydrophobicity, noting that longer alkyl side chains in IL cations enhance biofilm disruption and bacterial death. However, upon reaching a certain optimal chain length─usually C12 to C14─the antimicrobial activity of ILs starts to decrease. Furthermore, the symmetry and size of anions significantly impact biofilm elimination. This Perspective addresses a critical gap in biofilm research, revealing the structure-activity relationships of ILs and providing a foundation for designing more effective biofilm-disrupting agents.

Fabrication of PVA Coatings Applied to Electrospun PLGA Scaffolds to Prevent Postoperative Adhesions

There is currently a demand for anti-adhesive materials that are capable of preventing the formation of intra-abdominal adhesions. In this study, electrospun poly(lactide-co-glycolide) scaffolds were dip-coated in aqueous solutions of polyvinyl alcohol with concentrations of 3 wt.%, 6 wt.% and 9 wt.% to obtain a nontoxic and anti-adhesive biomedical material. The viscosities of the applied 3 wt.%, 6 wt.% and 9 wt.% polyvinyl alcohol solutions were 7.7 mPa∙s, 38.2 mPa∙s and 180.8 mPa∙s, respectively, and increased exponentially. It is shown that increasing the viscosity of the polyvinyl alcohol solution from 6 wt.% to 9 wt.% increases the thickness of the polyvinyl alcohol layer from (3.32 ± 0.97) µm to (8.09 ± 1.43) µm. No pronounced polyvinyl alcohol layer can be observed on samples dip-coated in 3 wt.% PVA solution. Increasing the viscosity of the polyvinyl alcohol solution from 3 wt.% to 9 wt.% increases the mechanical properties of the poly(lactide-co-glycolide) samples by a factor of 1.16-1.45. Cytotoxicity analysis of all samples reveals that none is toxic to 3T3-L1 fibroblast cells. A cell adhesion assay indicates that the anti-adhesion properties increase with increasing viscosity of the polyvinyl alcohol solution and the thickness of the polyvinyl alcohol layer on the poly(lactide-co-glycolide) scaffolds. Fluorescence images of the cells show that as the thickness of the polyvinyl alcohol coating increases, the number of cells decreases, and they do not cover the surface of the samples and form spherical three-dimensional agglomerates. The highest mechanical and anti-adhesion properties are obtained with the poly(lactide-co-glycolide) scaffold sample dip-coated in the 9 wt.% polyvinyl alcohol solution. This is because this sample has the thickest polyvinyl alcohol coating.

Cyano-functionalized porous hyper-crosslinked cationic polymers for efficient preconcentration and detection of phenolic endocrine disruptors in fresh water and fish

Sensitively analyzing phenolic endocrine-disrupting chemicals (EDCs) in environmental substrates and aquatic organisms provides a significant challenge. Here, we developed a novel porous hyper-crosslinked ionic polymer bearing cyano groups (CN-HIP) as adsorbent for the highly efficient solid phase extraction (SPE) of phenolic EDCs in water and fish. The CN-HIP gave an excellent adsorption capability for targeted EDCs over a wide pH range, and the adsorption capacity was superior to that of several common commercial SPE adsorbents. The coexistence of electrostatic forces, hydrogen bond, and π-π interactions was confirmed as the main adsorption mechanism. A sensitive quantitative method was established by coupling CN-HIP based SPE method with high-performance liquid chromatography for the simultaneously determining trace bisphenol A, bisphenol F, bisphenol B and 4-tert-butylphenol in fresh water and fish. The method afforded lower detection limits (S/N = 3) (at 0.03-0.10 ng mL-1 for water and 0.8-4.0 ng g-1 for fish), high accuracy (the recovery of spiked sample at 88.0%-112 %) and high precision (the relative standard deviation < 8.5 %). This work provides a feasible method for detecting phenolic EDCs, and also opens a new perspective in developing functionalized cationic adsorbent.

Antifungal Hybrid Graphene-Transition-Metal Dichalcogenides Aerogels with an Ionic Liquid Additive as Innovative Absorbers for Preventive Conservation of Cultural Heritage

The use and integration of novel materials are increasingly becoming vital tools in the field of preventive conservation of cultural heritage. Chemical factors, such as volatile organic compounds (VOCs), but also environmental factors such as high relative humidity, can lead to degradation, oxidation, yellowing, and fading of the works of art. To prevent these phenomena, highly porous materials have been developed for the absorption of VOCs and for controlling the relative humidity. In this work, graphene and transition-metal dichalcogenides (TMDs) were combined to create three-dimensional aerogels that absorb certain harmful substances. More specifically, the addition of the TMDs molybdenum disulfide and tungsten disulfide in such macrostructures led to the selective absorption of ammonia. Moreover, the addition of the ionic liquid 1-hexadecyl-3-methylimidazolium chloride promoted higher rates of VOCs absorption and anti-fungal activity against the fungus Aspergillus niger. These two-dimensional materials outperform benchmark porous absorbers in the absorption of all the examined VOCs, such as ammonia, formic acid, acetic acid, formaldehyde, and acetaldehyde. Consequently, they can be used by museums, galleries, or even storage places for the perpetual protection of works of art.