Laser engineered net shaping of antimicrobial and biocompatible titanium-silver alloys

Post-surgery infection is one of the main causes of orthopedic implant failure. This paper presents a powder-feed 3D printing strategy for fabrication of silver (Ag) incorporated titanium (Ti) alloys as an antimicrobial solution for orthopedic implants. Alloys with various Ag concentration, ranging from 0.5% to 2% by weight, were fabricated through laser engineered net shaping (LENS) process. The composition and surface of the fabricated alloys were characterized through X-ray diffraction, energy-dispersive X-ray spectroscopy, and 3D surface profiling. The mechanical properties, antimicrobial performance, and biocompatibility of the alloys were also investigated. Results showed that LENS fabricated Ti[sbnd]Ag alloys had a marginally higher microhardness and a lower ductility compared to pure Ti. Within only 3 h, Ti[sbnd]Ag alloys significantly reduced the bacterial attachment of both gram-positive and gram-negative strains by one to four orders of magnitudes. These alloys also demonstrated excellent in-vitro biocompatibility to human osteosarcoma cells. For the first time, laser engineered net shaping (LENS) of Ti[sbnd]Ag alloy has been explored as an antimicrobial solution for orthopedic applications and showed great potential for biomedical instrumentation.