Competitive adsorption of bovine serum albumin and lysozyme on a beta-tricalcium phosphate nanocoating

Abstract

Abstract The competitive and cooperative adsorptions of proteins on the surface of implanted materials can affect the biocompatibility and osteogenesis of the material. The adsorption processes are related to the properties of the materials, as well as to the nature of the proteins. Competitive adsorption of bovine serum albumin (BSA) and lysozyme (LSZ), both sequentially, and from a mixture, was investigated on a beta-tricalcium phosphate (β-TCP) nanocoating using quartz crystal microbalance with dissipation technique. In experiments with individual proteins, the BSA adlayer showed higher adsorption quality and viscoelasticity than the LSZ on the β-TCP surface. In the sequential adsorption of LSZ\u2009+\u2009BSA, protein exchange was observed but not in the BSA\u2009+\u2009LSZ sequence, because of the larger molecular and higher surface affinity of BSA relative to LSZ. The substitution rate increased as the increasing concentration of the BSA solution. With a BSA&LSZ mixture, the total amount of protein adsorbed was greater than that for individual or sequential adsorption, owing to the formation of BSA and LSZ agglomerates. The electrostatic force and affinity were dominant factors governing the adsorption behavior between BSZ and LSZ on the β-TCP surface. This work will be beneficial to understand the protein adsorption mechanism on β-TCP surface and provide information to design better osteogenic materials.