EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Bioactive glasses (BGs) are well-recognized multifunctional biomaterials for bone regeneration and wound healing applications. Protein adsorption on BG surfaces plays an essential role in determining biocompatibility, cell adhesion and proliferation as well as influencing a series of cellular pathways after cell-BG contact. Understanding protein adsorption on BGs is thus necessary for accelerating the development and applications of next-generation BG-based healthcare materials and devices. However, the influence of BG characteristics on protein adsorption has not been fully understood.
In this work, we investigated the influence of BG composition on protein adsorption. Specifically, two types of BGs, i.e., bulky 45S5 BG and BG nanoparticles (BGNs), were used to understand how glass composition could affect protein adsorption. A series of techniques including FTIR, XPS, ToF-SIMS and the BCA assay were used to characterize the amount and structure of adsorbed proteins. The results revealed that 45S5 BGs could adsorb a larger amount of bovine serum albumin (BSA) than bioinert glasses at different pHs. BSA adsorption on 45S5 BG surfaces was pH-dependent. Apatite formation on 45S5 BGs could enhance the amount of adsorbed BSA but it attenuated the trend of pH-dependent protein adsorption. For SiO2-CaO BGNs, the incorporated Ca did not significantly affect the particle size, specific surface area, and structure. The amount of adsorbed proteins increased over time at the early stage of adsorption (<2 h), regardless of glass composition and protein type (BSA and lysozyme). Further incubation of BGNs with proteins seemed to induce a reduced amount of adsorbed proteins, which was more significant in BGNs with higher Ca content. The results revealed that the composition of BGs indeed affected protein adsorption behavior. However, the influence is complicated and also depends on the types of BG, medium and protein.