Enclosed lipid bilayer structures, referred to as liposomes or lipid vesicles, have a wide range of biological functions, such as cellular signaling and membrane trafficking. The efficiency of cellular uptake of liposomes, a key step in many of these functions, is strongly dependent on the contact area between a liposome and a cell membrane, which is governed by the adhesion force w, the membrane bending energy κ, and the osmotic pressure Δp. Herein, we investigate the relationship between these forces and the physicochemical properties of the solvent, namely, the presence of glucose (a nonionic osmolyte). Using fluorescence microscopy, we measure the diffusivity D of small (∼50 nm radius), fluorescently labeled liposomes adhering to a supported lipid bilayer or to the freestanding membrane of a giant (∼10 μm radius) liposome. It is observed that glucose in solution reduces D on the supported membrane, while having negligible effect on D on the freestanding membrane. Using well-known hydrodynamic theory for the diffusivity of membrane inclusions, these observations suggest that glucose enhances the contact area between the small liposomes and the underlying membrane, while not affecting the viscosity of the underlying membrane. In addition, quartz crystal microbalance experiments showed no significant change in the hydrodynamic height of the adsorbed liposomes, upon adding glucose. This observation suggests that instead of osmotic deflation, glucose enhances the contact area via adhesion forces, presumably due to the depletion of the glucose molecules from the intermembrane hydration layer.
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http://dx.doi.org/10.1021/acs.langmuir.7b03364 | DOI Listing |
Sci Rep
December 2024
School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, China.
The dolomite dust-emulsified asphalt composite (DAC) with excellent mechanical properties was successfully prepared using alkali activation. The effects of different alkali concentrations and emulsified asphalt contents on the mechanical properties of the materials were studied. And the micro-mechanisms of its mechanical performance changes were analyzed through SEM and XRD characterization.
View Article and Find Full Text PDFNat Commun
December 2024
Laboratório de Vírus Respiratórios, Exantemáticos, Enterovírus e Emergências (LVRE), Oswaldo Cruz Foundation, Fiocruz, Rio de Janeiro, Brazil.
Zoonotic infections (swine-human) caused by influenza A viruses (IAVs) have been reported and linked to close contact between these species. Here, we describe eight human IAV variant infections (6 mild and 2 severe cases, including 1 death) detected in Paraná, Brazil, during 2020-2023. Genomes recovered were closely related to Brazilian swIAVs of three major lineages (1 A.
View Article and Find Full Text PDFHealth Expect
February 2025
Osteopathy Sciences Research Unit (URSO), Université Libre de Bruxelles (ULB), Brussels, Belgium.
Objective: Chronic musculoskeletal pain (CMSP) is frequent in chronic diseases, decreasing the quality of life of these patients. In a survey conducted in Belgium in 2019, chronic pain was named by patients as the main factor of complexity in their lives. The objective of our research was to provide elements to understand why and how CMSP contributes to the complexity of these people's lives.
View Article and Find Full Text PDFBackground: Seeking sexual partners in men who have sex with men (MSM) venues has been regarded as a high-risk behavior for HIV among MSM. Nevertheless, with the implementation of venue-based interventions and the change in the way MSM seek sexual partners, the continued status of MSM venues as the HIV risk factor remains inconclusive. This study endeavors to delve into this ambiguity by examining the MSM sexual contact network (SCN) as a foundation.
View Article and Find Full Text PDFJ Exp Orthop
January 2025
Department of Orthopedic Surgery and Traumatology, Freiburg University Hospital Albert Ludwigs University Freiburg Freiburg Germany.
Introduction: The medial patellofemoral ligament (MPFL) is the main patellar stabilizer in low knee flexion degrees (0-30°). Isolated MPFL reconstruction (MPFLr) is therefore considered the gold standard of surgical procedures for low flexion patellofemoral instabilities (PFIs). Despite excellent clinical results, little is known about the effect of MPFLr on kinematic parameters (KPs) of the patellofemoral joint in vivo.
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