Relationship between the Porous Structure Hierarchy and the Physical and Mechanical Properties of Calcium Phosphate Drug Carriers

A relationship between the structural-morphological and physical-mechanical properties of macro-porous calcium phosphate (CaP) coatings on the surface of titanium implants is studied. The produced CaP coatings can be used as carriers for target drug delivery in biomedical applications. The regularities of the formation of bulk (thickness of 15–130 μm) and rough (Ra = 1.7–8.5 μm) CaP coatings deposited by the micro-arc oxidation (MAO) method are studied. The coatings have a hierarchical porous structure and a uniform distribution of the structural elements (spheres and pores) over the surface. Correlations between the value of the applied voltage and structural-morphological and physical-mechanical characteristics of the CaP coatings have been established. The value of the coating adhesion strength has been determined with tensile tests. Both cohesive and mixed adhesive-cohesive pull-off of the MAO coating from the substrate have been identified.