scholarly journals Microparticle Deposition on Human Serum Albumin Layers: Unraveling Anomalous Adsorption Mechanism

2020 ◽  
Vol 4 (4) ◽  
pp. 51
Author(s):  
Małgorzata Nattich-Rak ◽  
Maria Dąbkowska ◽  
Zbigniew Adamczyk

Human serum albumin (HSA) layers are adsorbed on mica under controlled diffusion transport at pH 3.5 and various ionic strengths. The surface concentration of HSA is directly determined by AFM imaging of single molecules. It is shown that the adsorption kinetics derived in this way is quantitatively described using the random sequential (RSA) adsorption model. The electrokinetic characteristics of the HSA layers at various pHs comprising their zeta potential are acquired in situ while using the streaming potential method. It is shown that at pH 3.5 the zeta potential of mica becomes positive for HSA concentrations above 3000 μm−2. At larger pHs, HSA layers exhibit negative zeta potential for the entire range of coverage. Thorough characteristics of these monolayers at various pHs were performed applying the colloid deposition method involving negatively charged polystyrene microparticles. The kinetics of their deposition and their maximum coverage are determined as a function of the HSA layer surface concentration, pH, and ionic strength. An anomalous deposition of microparticles on substrates also exhibiting a negative zeta potential is observed, which contradicts the Derjaguin, Landau, Vervey, Overbeek (DLVO) theory. This effect is interpreted in terms of heterogeneous charge distribution that results from molecule concentration fluctuations. It is also shown that the maximum concentration of microparticles abruptly decreases with the electric double-layer thickness that is regulated by changing ionic strength, which indicates that their deposition is governed by electrostatic interactions. One can argue that the results obtained in this work can be exploited as useful reference data for the analysis of deposition phenomena of bioparticles on protein layers.

2015 ◽  
Vol 68 (12) ◽  
pp. 1894 ◽  
Author(s):  
Mohsen Oftadeh ◽  
Golamreza Rezaei Behbahani ◽  
Ali Akbar Saboury ◽  
Shahnaz Rafiei

The binding parameters between cyclodextrins (CDs) and human serum albumin (HSA) were investigated by isothermal titration calorimetry (ITC), fluorescence quenching, and UV-vis absorption spectroscopy at 300 K in 50 mM phosphate buffer solution. Among the various CDs investigated, β-CD has the greater ability to decrease the aggregation of HSA and the results indicated that the inhibition order is γ-CD < α-CD < β-CD. The obtained heats for HSA+CDs interactions were reported and analysed in terms of the extended solvation model, which was used to reproduce the enthalpies of HSA interactions with CDs over a broad range of complex concentrations. The binding constant and thermodynamic parameters were obtained. These suggested that the binding reaction was driven by both enthalpy and entropy, and electrostatic interactions played a major role in the stabilising of HSA. The parameters and reflected the net effect of β-CD on the HSA stability at low and high cyclodextrin concentrations, respectively. The positive values for indicated that β-CD stabilises the HSA structure at low concentrations. The UV absorption intensity of theses complexes increased and a slight red shift was observed in the absorbance wavelength with increasing the CD concentration. The fluorescence intensity of HSA decreased regularly and a slight blue shift was observed for the emission wavelength with increasing CD concentration. The results indicate that the CD complex could quench the fluorescence of HSA and changes the microenvironment of the tryptophan residue.


2011 ◽  
Vol 44 (13) ◽  
pp. S267
Author(s):  
Masoomeh Vahidzadeh ◽  
Mohsen Gharanfoli ◽  
Jamshid Chamani

Pharmaceutics ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 97 ◽  
Author(s):  
Gábor Katona ◽  
György Tibor Balogh ◽  
Gergő Dargó ◽  
Róbert Gáspár ◽  
Árpád Márki ◽  
...  

The aim of this study was to optimize the formulation of meloxicam (MEL)-containing human serum albumin (HSA) nanoparticles for nose-to-brain via a quality by design (QbD) approach. Liquid and dried formulations of nanoparticles containing Tween 80 and without the surfactant were investigated. Various properties, such as the Z-average, zeta potential, encapsulation efficacy (EE), conjugation of MEL and HSA, physical stability, in vitro dissolution, in vitro permeability, and in vivo plasma and brain distribution of MEL were characterized. From a stability point of view, a solid product (Mel-HSA-Tween) is recommended for further development since it met the desired critical parameters (176 ± 0.3 nm Z-average, 0.205 ± 0.01 PdI, −14.1 ± 0.7 mV zeta potential) after 6 months of storage. In vitro examination showed a significantly increased drug dissolution and permeability of MEL-containing nanoparticles, especially in the case of applying Tween 80. The in vivo studies confirmed both the trans-epithelial and axonal transport of nanoparticles, and a significantly higher cerebral concentration of MEL was detected with nose-to-brain delivery, in comparison with intravenous or per os administration. These results indicate intranasal the administration of optimized MEL-containing HSA formulations as a potentially applicable “value-added” product for the treatment of neuroinflammation.


2012 ◽  
Vol 41 (10) ◽  
pp. 1777-1801 ◽  
Author(s):  
Behnaz Bakaeean ◽  
Mona Kabiri ◽  
Hedieh Iranfar ◽  
Mohammad Reza Saberi ◽  
Jamshidkhan Chamani

2017 ◽  
Vol 242 ◽  
pp. 1018-1026 ◽  
Author(s):  
Otávio Augusto Chaves ◽  
Bijo Mathew ◽  
Dari Cesarin-Sobrinho ◽  
Balasubramanian Lakshminarayanan ◽  
Monu Joy ◽  
...  

2021 ◽  
Author(s):  
Thais Meira Menezes ◽  
Caio Rodrigo Dias de Assis ◽  
Antonio Marinho da Silva Neto ◽  
Priscila Gubert ◽  
Marcos Gomes Ghislandi ◽  
...  

Azo dyes like Drimaren Red CL-5B (DR, CI Reactive Red 241) represent a class of compounds extensively used in the textile industry and are extremely dangerous to the environment and human health. Therefore, understanding the binding characteristics between such substances and biological macromolecules is essential from a toxic-kinetic perspective. The molecular interaction between DR and Human Serum Albumin (HSA) was investigated through spectroscopic techniques and molecular docking approaches. The results indicate that DR quenches HSA fluorescence following a static mechanism (corroborated by UV-Vis studies) with a moderate interaction (Ka~105 M-1), guided by electrostatic interactions (DS> 0 and DH< 0). DR is 5.52 nm distant from fluorophore residue Trp-214 (according to FRET investigations), and the interaction is mainly related to Tyr residues (as revealed by synchronous fluorescence). The Ellman assay identified a decrease in the content of HSA free thiol. The results of the RLS demonstrate that there are HSA alterations, suggesting damage to the confirmation of the protein. Molecular docking suggests the binding site of DR was located in subdomain IIB HSA, corroborating the experimental properties. Finally, the results suggest a high potential for DR toxicity triggered by contact with key proteins, which affects the biomolecule functionalities.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1017 ◽  
Author(s):  
Tatiana V. Plisko ◽  
Alexandr V. Bildyukevich ◽  
Katsiaryna S. Burts ◽  
Sergey S. Ermakov ◽  
Anastasia V. Penkova ◽  
...  

A novel method for one-step preparation of antifouling ultrafiltration membranes via a non-solvent induced phase separation (NIPS) technique is proposed. It involves using aqueous 0.05–0.3 wt.% solutions of cationic polyelectrolyte based on a copolymer of acrylamide and 2-acryloxyethyltrimethylammonium chloride (Praestol 859) as a coagulant in NIPS. A systematic study of the effect of the cationic polyelectrolyte addition to the coagulant on the structure, performance and antifouling stability of polysulfone membranes was carried out. The methods for membrane characterization involved scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), contact angle and zeta-potential measurements and evaluation of the permeability, rejection and antifouling performance in human serum albumin solution and surface water ultrafiltration. It was revealed that in the presence of cationic polyelectrolyte in the coagulation bath, its concentration has a major influence on the rate of “solvent–non-solvent” exchange and thus also on the rate of phase separation which significantly affects membrane structure. The immobilization of cationic polyelectrolyte macromolecules into the selective layer was confirmed by FTIR spectroscopy. It was revealed that polyelectrolyte macromolecules predominately immobilize on the surface of the selective layer and not on the bottom layer. Membrane modification was found to improve the hydrophilicity of the selective layer, to increase surface roughness and to change zeta-potential which yields the substantial improvement of membrane antifouling stability toward natural organic matter and human serum albumin.


2011 ◽  
Vol 25 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Chuanxian Wang ◽  
Qinghua Chu ◽  
Changyun Chen ◽  
Zhao Bo

Fluorescence spectroscopy, UV absorption, circular dichroism (CD) spectroscopy and molecular modeling methods were used to characterize the binding properties of thiacloprid (TL) with human serum albumin (HSA) at molecular level under physiological conditions. The fluorescence intensity of HSA decreased regularly with the gradually increasing concentration of thiacloprid. The binding constant K at three different temperatures (290, 300 and 310 K) were 3.07, 2.74 and 1.35 × 104M−1, respectively, for TL–HSA interaction have been calculated from the relevant fluorescence data. CD spectroscopic measurements have shown that the secondary structures of the protein have been changed by the interaction of thiacloprid with HSA. Furthermore, the study of molecular modeling indicated that thiacloprid could be located on the surface of the binding pocket of subdomains IIA in HSA. The hydrophobic interaction was the major acting force and there are H-bonds and electrostatic interactions between TL and HSA, which is in good agreement with the results from the experimental thermodynamic parameters (the enthalpy change ΔH0and the entropy change ΔS0were calculated to be -20.378 kJ/mol and 16.328 J/mol K according to the Van9t Hoff equation).


Sign in / Sign up

Export Citation Format

Share Document