Development of a bone substitute material based on additive manufactured Ti6Al4V alloys modified with bioceramic calcium carbonate coating: Characterization and antimicrobial properties

This investigation shows that composite structures based on additive manufactured electron beam melted Ti6Al4V scaffolds coated with calcium carbonate particles can be used as a potential biocomposites for bone substitutes. A continuous bioceramic coating of CaCO3 was deposited on additive manufactured titanium alloy under the influence of ultrasound. XRD analysis revealed the formation of a mixture of calcite and vaterite phases. CaCO3 coating led to decreasing roughness of additively manufactured (AM) scaffolds and improved surface hydrophilicity. In vitro assay demonstrated enhanced inorganic bone phase formation on the surface of CaCO3-coated AM scaffolds compared to as-manufactured ones. The short-term adhesion of S. aureus onto sample surface was evaluated by fluorescent microscopy 0, 3, and 72 h after cell seeding. It revealed that the surface modification resulted in the decreased number of bacteria attached to the surface after CaCO3 deposition. The morphology, roughness, solubility and superhydrophilic character of the CaCO3 coated EBM-manufactured Ti6Al4V alloy surface are suggested as factors contributing to preventing S. aureus adhesion. Thus, the developed biocomposites based on additively manufactured Ti6Al4V alloy scaffolds and CaCO3 coating can be successfully used in bone tissue regeneration providing the effective growth of inorganic bone phase and preventing the bacteria adhesion.