Smart thin porous calcium phosphate coatings for local antibiotic delivery

Objective: Implant failure after arthroplasty, primarily due to aseptic loosening or periprosthetic joint infection, remains a significant clinical problem. Bioactive ceramic coatings, such as β-tricalcium phosphate (β-TCP), enhance osseointegration and may reduce the risk of aseptic loosening. At the same time, localized antibiotic release from the implant surface represents a promising strategy to prevent early bacterial colonization. The aim of this study was to evaluate the feasibility of incorporating the heat-sensitive antibiotic vancomycin (VAN) into β-TCP coatings using high-velocity suspension flame spraying (HVSFS). Results: We successfully embedded VAN into β-TCP coatings by preparing suspensions containing VAN-loaded supraparticles as feedstock for the HVSFS process. High-performance liquid chromatography analysis confirmed that VAN maintained its chemical integrity during spraying, with spectra comparable to untreated controls, indicating no thermal degradation. The resulting multifunctional coatings therefore combined the osteoconductive potential of β-TCP with the antibacterial activity of VAN. These findings demonstrate that HVSFS is a viable technique for producing bioactive coatings that simultaneously promote bone integration and enable local antibiotic delivery, offering a potential strategy to mitigate both aseptic loosening and infection risks in arthroplasty.