Characterization and in vitro testing of layers formed by immersion of ZnMgSr alloy in model body environments
Zinc and its alloys are considered as a member of the group of the biodegradable metals. This metallic element is essential for various processes in the human body. The most important property, which is connected with the orthopaedic applications, is the participation of zinc on bone metabolism as a part of proteins and enzymes. Another crucial aspect of zinc usability as an orthopaedic implant is the degradation process. For now, various tests of the corrosion properties in inorganic models were measured by researches group all over the world. However, only a few studies based on the behaviour of zinc materials in the environments containing proteins were published. Those environments can simulate the initial stages of degradation more precisely than the only inorganic one. The significance of the knowledge of this mechanism is obvious. Presence of proteins can significantly affect the degradation rate as well as the ion release. In this study, the ZnMg0.8Sr0.2 ternary alloy was pre-treated in a phosphate-buffered solution (PBS) or in PBS containing 1 % of bovine serum albumin (BSA). In order to reveal the changes in the surface properties of the material, the surfaces were analysed from the point of view of wettability and roughness. Besides, the morphology and the elemental composition of the newly created formations were analysed. It was found that the pre-treatment of the samples positively affects the surface properties, especially the wettability of the materials. In addition, the influence of the pre-treatment on cell viability was observed as well. This study describes the initial stages of the degradation of zinc alloys and a level of the protein influence on the creation of specific products on the material surface.