Competitive protein adsorption on silicate bioactive glasses

Recent studies have highlighted a poor correlation between the outcomes of in vitro and in vivo characterization of biomaterials. This highlights the poor reliability of the current in vitro models, caused by the lack of knowledge concerning the early-stage interactions between the implanted material and its surrounding tissue, which is largely regulated by protein adsorption on implant. This study investigates the adsorption kinetics of human serum albumin (HSA), immunoglobulin G (IgG), and fibronectin (FN), which are the main protein constituents of human blood plasma, on the clinically available silicate bioactive glass S53P4 before and after surface modification by conditioning and silanization, respectively. Vroman effect was evaluated in real time by an electrokinetic analyzer, and protein adsorption studied and quantified by fluorescence confocal microscopy. IgG and FN, promoters of cell adhesion, displaced the antifouling HSA on the untreated and conditioned glasses, while a long-lasting affinity persisted between the silanized surfaces and HSA. This study provides a foundation for understanding how surface properties influence the Vroman effect on bioactive glasses, enabling the development of more predictive in vitro models and improved control of cell behavior.