Protein interactions with bioactive glass surfaces: A review

Bioactive glasses (BGs) are an important class of biomaterials being proposed for several biomedical applications including bone/soft tissue regeneration, bone substitute materials, bioactive orthopedic coatings, wound healing, cancer treatment, and drug delivery. Adsorption of proteins onto bioactive glass (BG) surfaces is the initial interaction between BGs and the biological medium, e.g., blood plasma, interstitial fluids. Protein adsorption plays an essential role in determining biocompatibility, cell adhesion and proliferation as well as influencing a series of cellular pathways after cell-material contact. Understanding the adsorption of proteins on BGs is thus necessary for accelerating the development and applications of next-generation BG-based healthcare materials and devices. In this review, we comprehensively cover previous literature regarding protein adsorption on BG surfaces. The factors impacting protein adsorption on these bioreactive materials are summarized and discussed. In particular, the influence of BG surface properties (e.g., surface topography, composition) on protein adsorption is highlighted. The effects of adsorbed proteins on the surface properties of BGs, in terms of biological response, biomineralization (hydroxyapatite formation in contact with biological fluids), and BG dissolution, are also covered in this review. The paper discusses the methods suitable to analyze the protein adsorption process and to characterize possible changes in the structure of adsorbed proteins, and also presents approaches to control the protein adsorption phenomenon. A discussion on applications of protein adsorbed BGs is also included. The review also highlights the current challenges and uncertainties in this field and discusses future research directions. (C) 2019 Elsevier Ltd. All rights reserved.