The interfacial adsorption of proteins is a problem during processing and formulation. The flexibility and aggregation of the protein cause the formation of a viscoelastic multilayer upon adsorption to the oil/water interface. Protein adsorption is a complex process and therefore it is difficult to elaborate which protein characteristics are important for the interfacial protein adsorption. From our results it seems that the molecular weight influences this the most. In this study, the adsorption of three proteins, bovine serum albumin (BSA), lysozyme and insulin, to oil/water interfaces is characterized by interfacial shear stress measurements using a sensitive rheometer equipped with a Du Noüy ring geometry. The interfacial protein adsorption is concentration dependent for the three proteins investigated, where the complex viscosity of the viscoelastic multilayer increases with increased concentration. The adsorption rate of the proteins varies, BSA reaches a plateau after 2h, insulin takes 24h to reach a plateau value and lysozyme adsorbs fast in the beginning, then levels of to a slow but steady increase in the complex viscosity, BSA and insulin were shown to have similar characteristics in the evolvement of the interfacial layer despite the rate, indicating similar mechanism of adsorption, whereas lysozyme differs. This is also seen when G' and G'' are used in order to relate the rheological measurements to the three adsorption regimes. This study shows the potentials and effectiveness of the Du Noüy ring geometry for characterization of protein adsorption to oil/water interfaces.
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http://dx.doi.org/10.1016/j.colsurfb.2010.03.020 | DOI Listing |
Soft Matter
January 2025
Physical Chemistry, Chemistry Centre, Lund University, SE-22100 Lund, Sweden.
We have investigated the adsorption of the amyloid-forming protein α-Synuclein (αSyn) onto small unilamellar vesicles composed of a mixture of zwitterionic POPC and anionic POPS lipids. αSyn monomers adsorb onto the anionic lipid vesicles where they adopt an α-helical secondary structure. The degree of adsorption depends on the fraction of anionic lipid in the mixed lipid membrane, but one needs to consider the electrostatic shift of the serine p with increasing fraction of POPS.
View Article and Find Full Text PDFWater Res X
May 2025
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
Emerging organophosphate flame retardants (E-OPFRs) are a new class of pollutants that have attracted increasing attention, but their bioaccumulation patterns and trophodynamic behaviors in aquatic food webs still need to be validated by comparison with legacy OPFRs (L-OPFRs). In this study, we simultaneously investigated the bioaccumulation, trophic transfer, and dietary exposure of 8 E-OPFRs and 10 L-OPFRs in a tropical estuarine food web from Hainan Island, China. Notably, the ΣL-OPFRs concentration (16.
View Article and Find Full Text PDFJ Biosci Bioeng
January 2025
Department of Chemical Systems Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan. Electronic address:
The bioartificial pancreas, composed of a semi-permeable hydrogel encapsulating insulin-secreting cells, has attracted attention as a treatment for type 1 diabetes. In this study, we developed phospholipid polymer-modified alginate hydrogel beads that encapsulated spheroids of the pancreatic beta cell line MIN6. The hydrogel beads were composed of methacrylated alginic acid, which enabled both ionic and covalent cross-linking, resulting in a hydrogel that was more stable than conventional alginate hydrogels.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Institute of Microfluidic Chip Development in Biomedical Engineering, College of Information Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China. Electronic address:
Background: Digital recombinase polymerase amplification (dRPA) is an effective tool for the absolute quantification of nucleic acids and the detection of rare mutations. Due to the high viscosity or other physical properties of the reagent, this can compromise the accuracy and reproducibility of detection results, which limits the broader adoption and practical application of this technology. In this study, we developed an asymmetric contact angle digital isothermal detection (ACA-DID) chip and optimized the ACA-DID chip structure to achieve rapid digital recombinase polymerase amplification.
View Article and Find Full Text PDFEnviron Res
January 2025
State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong 999077, China; School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Hong Kong Kowloon, 999077, China. Electronic address:
Bisphenol A (BPA) is a commonly used endocrine-disrupting chemical found in high levels in wastewater worldwide. Aerobic denitrification is a promising alternative to conventional nitrogen removal processes. However, the effects of BPA on this novel nitrogen removal process have rarely been reported.
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