In Vitro Study of the Influence of Lattice Structures on the Antibacterial Activity of Bone Cement

Abstract

Introduction. Orthopedic implant infections are a serious concern. Local antibiotic delivery via polymethylmethacrylate (PMMA) bone cement is a common preventive strategy, but its release profile is suboptimal. Aim of the study. To study in an in vitro experiment the influence of lattice structures of base implants on the antibacterial activity of antibiotic-impregnated bone cement. Materials and methods. Additively manufactured lattice structures (V2, V3) and a solid cylinder (C) were filled with Synicem 1 cement loaded with vancomycin or cefazolin (5% wt.). Samples were incubated in saline at 37°C. Antibiotic release activity againstStaphylococcus aureusstrains (MSSA, MRSA) was assessed at 6, 12, 24, 48, and 96 hours via broth dilution (MIC assay). Efficacy was expressed as release rate (MIC/h). Results. Lattice structures V2 and V3 significantly increased the rate and duration of antibiotic release compared to the solid control. For cefazolin, lattice samples provided at least a two-fold higher release rate, sustaining levels 2 MIC for 96 hours. For vancomycin, lattice structures showed superior early- and mid-stage release, with a later decline to subtherapeutic levels (1 MIC/h) than the control. This enhanced elution occurred despite a lower cement volume, highlighting the crucial role of increased surface area. Conclusion: The use of lattice structures is an effective strategy for improving antibiotic elution from bone cement for the prevention of orthopedic infections. This approach overcomes a key limitation of traditional PMMA – the short duration of effective release – by providing a higher initial concentration and prolonged antimicrobial activity without changing the cement composition. The obtained results open prospects for the development of more effective implants for the prevention and treatment of orthopedic infections.