Enhanced Stability of Gold Nanoparticles with Thioalkylated Carboxyl-Terminated Ligands for Applications in Biosensing

Abstract

Fragmentation of ?-glucans secreted by the fungus Ophiocordyceps dipterigena BCC 2073 achieved by microfluidization was investigated. The degree of ?-glucan fragmentation was evaluated based on the average number of chain scissions (?). The effects on the ? value of experimental variables like solid concentration of the ?-glucan suspension, interaction chamber pressure, and number of passes through the microfluidizer were examined. Kinetic studies were conducted using the relationships of the ? and suspension viscosity values with the number of passes. Evidence indicated that ? increases with the interaction chamber pressure and the number of passes, whereas the solid concentration shows the inverted effect. Kinetic data indicated that the fragmentation rate increases with ?-glucan solid concentration and interaction chamber pressure. Furthermore, since ?-glucan molecular weight is a key factor determining its biological activity, the effect of ?-glucans of different molecular weights produced by fragmentation on tumor necrosis factor (TNF)-?-stimulating activity in THP-1 human macrophage cells was investigated. Evidence suggested that ?-glucans have an immunostimulating effect on macrophage function, in the absence of cytotoxic effects. Indeed, ?-glucans characterized by a range of molecular weights produced via microfluidization exhibited promise as immunostimulatory agents. ? 2024 National Science and Technology Development Agency, THAILAND