The use of additive manufacturing (AM) in biomedical engineering has transformed how medical implants are made, particularly with polyetheretherketone (PEEK), a high-performance polymer known for its mechanical strength, biocompatibility, and radiolucency. Despite these advantages, PEEK implants still face clinical challenges related to antimicrobial performance and osseointegration. This study introduces a new hybrid manufacturing method that combines Fused Filament Fabrication (FFF) 3D printing with in-situ vacuum arc plasma deposition to create antimicrobial and bioactive thin-film coatings on PEEK implants. This approach offers a path to personalized, antimicrobial, and osseointegrative implants where infection control and tissue integration are critical.

The study focuses on using this method to apply various metal and metal oxide coatings onto 3D-printed PEEK in a single fabrication step. Metals like silver (Ag), copper (Cu), and zinc (Zn) were selected for their antimicrobial properties, while titanium dioxide (TiO₂) was chosen for its ability to promote bone integration. Surface characterization with a laser scanning microscope (LSM) shows that the thin-film coatings preserve the substrate’s surface structure and only slightly alter its roughness. However, TiO₂ coatings significantly increase surface wettability. Cross-cut adhesion tests confirm strong bonding between the coatings and the PEEK substrate.

Bacterial adhesion tests reveal that, among the tested metal coatings, Zn offer the highest antimicrobial efficacy against Staphylococcus aureus, achieving a notable reduction in bacterial counts at a minimum coating thickness of 20 nm. Additionally, TiO₂ coatings enhance osteoblast adhesion and proliferation, improving PEEK’s bioactivity. A composite TiO₂/Zn coating demonstrated both strong antimicrobial protection and support for bone growth, suggesting it could help reduce post-surgical infections while promoting osseointegration. Further, the tests for cytotoxicity to fibroblastic cells reveal satisfactory biocompatibility of the TiO₂/Zn coating.

Future research will focus on fine-tuning the coating configurations to balance antimicrobial activity with biocompatibility, further preparing these advanced 3D-printed PEEK implants for clinical use in infection prevention.