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.