Fused deposition modeling significantly reduces bioburden

Additive manufacturing (AM), particularly fused deposition modeling (FDM), holds promise for producing surgical instruments in austere settings. However, standard sterilization methods often degrade thermoplastics used in FDM. This study evaluates whether the high temperatures inherent to FDM can reduce bioburden on post-print materials.

Polycarbonate filament was inoculated with E. coli and S. aureus and then 3D printed at 260°C or 300°C. Printed samples and preprint controls were cultured under aerobic, anaerobic, and fungal conditions. Sterility was assessed over a 14-day incubation period.

Out of 30 printed samples, 5 (16.6%) showed microbial contamination, compared to 30/30 (100%) positive controls (p≪< 0.01). No significant difference was found between print temperatures or culture conditions.

FDM significantly reduced microbial contamination under non-sterile operating conditions. This suggests further investigations should focus on a potential FDM single-stage, point-of-care sterilization method. Further work is needed to define critical parameters and validate efficacy against more resilient pathogens.