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Polyelectrolyte multilayers (PEMs) are widely utilized in membrane technologies, biosensing, and drug delivery, where precise control over permeability, which refers to the ease of transport through the multilayer, is essential. While the influence of anions on PEMs is well-documented, the role of countercations in regulating transport properties through films remains underexplored. Here, we investigate the effects of sodium (Na) and potassium (K) countercations on the formation, structure, permeability, and transport properties of PAH/PSS and PDADMAC/PSS multilayers. Using a quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy, we demonstrate that K-assembled films exhibit higher mass, denser packing, and significantly reduced permeability compared to Na-assembled films. Extended characterizations reveal selected permeability toward ionic probes and frequency-dependent impedance behavior in K, underscoring the potential of the films as tunable barriers. We further demonstrate their application in a model drug release system, highlighting controlled release profiles influenced by countercation choice. These findings provide insights into cation-mediated tuning of PEM properties, offering a robust strategy for designing advanced materials for separation, sensing, and biomedical applications.
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http://dx.doi.org/10.1021/acs.langmuir.5c01594 | DOI Listing |
Methods Cell Biol
September 2025
Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Italy; CEINGE-Biotecnologie Avanzate, Naples, Italy.
Cystic fibrosis (CF) is a genetic disorder primarily known for its severe impact on lung function, but it also significantly affects the digestive system, leading to complications such as intestinal blockages, malabsorption, inflammation, and microbial dysbiosis. The study of CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) effects on intestinal physiology is critical for developing new effective treatments. This work highlights the use of the mouse intestine as a valuable model for analyzing cellular electrophysiology and CFTR function.
View Article and Find Full Text PDFPhysiol Plant
September 2025
Faculty of Bioscience Engineering, Department of Plants and Crops, Laboratory of Plant Ecology, Ghent University, Ghent, Belgium.
Plant water potential is one of the most frequently measured variables of plant water status. Stem water potential, often approximated by wrapping the leaves, is assumed to be more stable and a better measure of drought stress than leaf water potential. In wheat (Triticum aestivum L.
View Article and Find Full Text PDFJ Leukoc Biol
September 2025
Laboratory of Immunobiology and Ionic Transport Regulation, Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Av. 25 de Julio 965, Villa de San Sebastián, 28045 Colima, México.
Ion channels are integral membrane proteins which facilitate rapid transport of small ions into and out of the cell and between organelles and cytosol. Cytolytic lymphocytes including natural killer (NK) cells principally kill virus-infected and cancer cells by releasing cytolytic granules within the immunological synapse, formed between target and effector cells. This process strongly depends on Ca2+ signaling, which in human NK cells is controlled by the phospholipase C (PLCγ)/inositol-1,4,5-triphospate receptor (IP3R)/calcium release-activated calcium channel (CRAC) axis.
View Article and Find Full Text PDFNat Rev Mol Cell Biol
September 2025
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA.
The defining property of eukaryotic cells is the storage of heritable genetic material in a nuclear compartment. For eukaryotic cells to carry out the myriad biochemical processes necessary for their function, macromolecules must be efficiently exchanged between the nucleus and cytoplasm. The nuclear pore complex (NPC) - which is a massive assembly of ~35 different proteins present in multiple copies totalling ~1,000 protein subunits and architecturally conserved across eukaryotes - establishes a size-selective channel for regulated bidirectional transport of folded macromolecules and macromolecular assemblies across the nuclear envelope.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
Affiliated Hospital of Shandong Second Medical University, Shandong Second Medical University, Weifang, Shandong 261053, P.R. China.
Decades of antibiotic misuse have spurred an antimicrobial resistance crisis, creating an urgent demand for alternative treatment options. Although phototherapy has therapeutic potential, the efficacy of the most advanced photosensitizers (PS) is essentially limited by aggregation-induced quenching, which significantly reduces their therapeutic effect. To address these challenges, we developed a cationic metallocovalent organic framework (CRuP-COF) via a solvent-mediated dual-reaction synthesis strategy.
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