Comprehensive evaluation of morphology-property relationship in porous zirconia bioceramics at different levels of scale hierarchy

Abstract

The success of replacement of damaged bone tissue by porous ceramic scaffolds is determined not only by biochemical compatibility of the artificial material, but also by a set of interrelated morphological and mechanical characteristics. But even if all parameters are optimized, the implant can be rejected on account of the low cell adhesion. Cell adhesion is the first step towards the survival of the implant material. Therefore, a challenging issue is still the search for mechanisms of controlling the behavior of cells on the surface of the implant. According to new ideas, the cellular response is influenced no only by the chemical composition and surface energy of the implant but also by the material structure at the micro- and nanoscale levels. To date, the only way to take into account structural features of a material is to determine the fractal dimension. The paper is devoted to the study of structure-property-adhesion relationships at different scale levels of ZrO2 and ZrO2-Al2O3 bioceramics with pore structures of different morphology. Physical regularities are revealed for the relationship between the geometry of pore-forming particles, crystal structure parameters, strength, and fracture toughness of the ceramics. The correlation between the fractal dimension as an integral morphological characteristic of the material and the cellular activity of the 3T3 line is evaluated for the first time. This can be a universal method for assessing the relationship between the structure and osteoreplacement efficiency of ceramics.