Effect of geometric modification of fumed nanoscale silica for medical applications on adsorption of human serum albumin: Physicochemical and surface properties.

The influence of the geometric modification (GM) of fumed nanoscale silica A300 (NS) on the adsorption capacity of human serum albumin (HSA) as well as the physicochemical and textural properties of the protein/nanosilica system was analyzed. An effective medical enterosorbent based on fumed nanosilica was designed and produced in the Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine. To design an effective nanomaterial for biomedical applications as a wound-healing material, the adsorption, physicochemical and surface properties of the initial nanosilica (NS), nanosilica after geometric modification (GM-nanosilica), and HSA/nanosilica biocomposites were characterized. The differences in sorption capacities, acid-base, textural, and surface properties of the obtained materials were monitored using the diffuse UV–vis reflectance spectroscopy, the potentiometric titration of suspension, the nitrogen adsorption/desorption isotherms, the scanning electron microscopy with the energy dispersive X-ray microanalysis and the digital optical microscope. For a deeper understanding of the nature of immobilized HSA molecules on the nanosilica and GM-nanosilica, the surface functional groups were characterized by the FTIR spectroscopy. It was found that the adsorption properties, physicochemical and textural characteristics of fumed nanoscale silica depend on the mechanical treatment time (t MT) and bulk density (d b). In fact, as the t MT increases, the d b of initial fumed nanosilica increases, and the protein adsorption capacity decreases, however, it remains at an acceptable level: 0.075 g/g, 0.056 g/g, 0.032 g/g for GM-nanosilica after 1, 4, and 7 h of mechanical treatment, respectively. HSA adsorption significantly changes the surface morphology, acid-base character, and structure of both unmodified and modified nanosilica. [Display omitted] • Mechanical treatment leads to significant changes in enterosorbents bulk density. • Methods for the production of fumed silica based bionanocomposites have been developed. • Decrease of protein adsorption with an increased nanosilica bulk density observed. • Physicochemical properties change of biocomposites HSA/NS and HSA/GM-nanosilica. • Topography, nanostructure, chemical composition of HSA/nanosilica surface analyzed. [ABSTRACT FROM AUTHOR]