Adsorption of HSA, IgG and laminin-1 on model titania surfaces – effects of glow discharge treatment on competitively adsorbed film composition

Abstract

This study investigated the effect of glow discharge treatment of titania surfaces on plasma protein adsorption, by means of ellipsometry and mechanically assisted SDS elution. The adsorption and film elution of three plasma proteins, viz. human serum albumin (HSA), human immunoglobulin G (IgG) and laminin-1, as well as competitive adsorption from a mixture of the three proteins, showed that the adsorbed amount of the individual proteins after 1 h increased in the order HSA <IgG <laminin-1 ≤ protein mixture. Film elutability showed that 30 min of SDS interaction resulted in almost complete removal of adsorbed films. No difference in the total adsorbed amounts of individual proteins, or from the mixture, was observed between untreated and glow discharge treated titania surfaces. However, the composition of the adsorbed films from the mixture differed between the untreated and glow discharge treated substrata. On glow discharge-treated titania the fraction of HSA increased, the fraction of laminin-1 decreased and the fraction of IgG was unchanged compared to the adsorption on the untreated titania, which was attributed to protein–protein interactions and competitive/associative adsorption behaviour.

Keywords:

• human serum albumin, laminin
• immunoglobulin
• ellipsometry
• gel electrophoresis
• implant surface

Acknowledgments

The authors are grateful to Professor Ann Wennerberg, Malmö University, for providing them with the titania surfaces. This study was supported by research grants from the Knowledge Foundation (KK stiftelsen, Biofilms-research centre for biointerfaces), the Swedish Laryng Foundation and Malmö University. Thomas Arnebrant acknowledges the Gustaf Th Ohlsson foundation for financial support.