Aluminum hydroxide (AH) salts are widely used as vaccine adjuvants and controlling antigen-AH interactions is a key challenge in vaccine formulation. In a previous work, we have developed a quartz crystal microbalance (QCM) platform, based on stable AH-coated sensors, to explore the mechanisms of model antigen adsorption. The QCM study of bovine serum albumin (BSA) adsorption at different pH and ionic strength (I) values showed that protein adsorption on AH adjuvant at physiological pH cannot be explained mainly by electrostatic interactions, in contrast with previous reports. Here, we exploit further the developed QCM platform to investigate the role of phosphate-hydroxyl ligand exchanges in the adsorption mechanism of BSA, human serum albumin (HSA) and ovalbumin (OVA) on two commercial AH adjuvants. BSA adsorption decreased on immobilized AH particles previously treated with KHPO, highlighting the role of exchangeable sites on AH particles in the adsorption process. BSA and OVA were dephosphorylated by treatment with an acid phosphatase to decrease their phosphate content by about 80% and 25%, respectively. Compared to native BSA, adsorption of dephosphorylated BSA decreased significantly on one AH adjuvant at pH 7. Adsorption of dephosphorylated OVA was comparable to the one of native OVA. Further QCM assays showed that phospho-amino acids (PO-serine and PO-threonine) displaced previously adsorbed BSA and OVA from AH particles in conditions that were depending on the protein and the AH. Taken together, these observations suggest that phosphate-hydroxyl ligand exchange is an important adsorption mechanism of proteins on AH. These results moreover confirm that the developed AH-coated QCM sensors offer a new platform for the study of antigen adsorption, to the benefit of vaccine formulation.
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http://dx.doi.org/10.1016/j.ijpharm.2019.118834 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Key Laboratory of Textile Fiber and Products, Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Intelligent Textile Materials & Application, Wuhan Textile University, Wuhan 430200, China.
Constructing a nanofibrous membrane with high flow rate surface pore structure and high-density ligand chemical structure is a promising strategy to balance the trade-off between high flow rates and high adsorption capacity for protein separation and purification. Herein, a nanofiber-based ion-exchange chromatography membrane with a periodic diagonal surface structure and high ionic strength ligands was fabricated using dispersion cross-linking, wet coating, and template printing with a three-wire diagonal woven mesh. For this membrane, EVOH nanofibers were used as skeleton, glutaraldehyde (GA) as cross-linking agent, and quaternized chitosan (QCS) as binder and functional ligand.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Chemistry and Chemical Engineering, Hunan Provincial Engineering Research Center for Functional Membranes, Hunan University of Science and Technology, Xiangtan 411201, China.
Int J Biol Macromol
December 2024
School of Pharmacy, Binzhou Medical University, Yantai 264003, China. Electronic address:
Different kinds of proteins interact with the digestible lipids in various ways, affecting the adsorption behavior of proteins and digestion. The ordered porous layer interferometry (OPLI) system was constructed by the silica colloidal crystal (SCC) films used to monitor the real-time binding assessment between bovine serum albumin (BSA), casein, fibrinogen, and triolein. The OPLI system reflected the changes in protein mass on the SCC films in real time through the migration of the interference spectrum of the SCC films, which was converted into the changes in optical thickness (ΔOT) that can be monitored.
View Article and Find Full Text PDFJ Fluoresc
December 2024
National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080, Pakistan.
This paper describes the synthesis of CoFe₂O₄ nanoparticles via a simple ultrasonic-assisted co-precipitation method and their functionalization with thiol groups using (3-Mercaptopropyl)trimethoxysilane (MPTS) as the functionalizing agent. The use of ultrasonic energy not only serves as a green energy source but also reduces the reaction time fivefold compared to conventional methods. The synthesized CoFe₂O₄ nanoparticles were characterized for their surface and internal properties using instrumental techniques such as Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Vibrating Sample Magnetometer (VSM).
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, PR China. Electronic address:
Wound infections caused by pathogenic bacteria can cause delayed wound healing and even threaten the life of patients. Drug resistance and effectiveness with regard to traditional wound dressings have become urgent issues which need to be addressed. The antibacterial effect of hydrogels, as novel wound dressings, is through contact-active antibacterial was limited by the contact area and time.
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