Silver segregation and bacterial growth of intraventricular catheters impregnated with silver nanoparticles in cerebrospinal fluid drainages

Objectives: Intraventricular catheters impregnated with silver nanoparticles are developed to reduce catheter-associated infections in cerebrospinal fluid (CSF) drainages. Silver released from these new catheters should have an anti-microbacterial effect. This study examines the silver ion release and a potential effect of bacterial growth in an in vitro experiment. Methods: Seven original silver-coated ventricle catheters were rinsed thoroughly with an artificial CSF for 6 days. The collecting containers were replaced every 24 hours. In these samples, ion concentrations of silver were determined via trace analysis through atomic absorption spectroscopy. Furthermore, a bacterial growth was conducted on silver-impregnated and non-impregnated catheters. Results: In none of the samples, a concentration of silver ions could be detected. For Staphylococcus aureus, a slightly decreased bacterial growth could be observed with silver-impregnated catheters. Discussion: There is no risk of a toxic effect due to silver release into the CSF. However, the in vivo antibacterial effect has to be further investigated. We recommend clinical trials to prove the oligodynamic and anti-microbacterial effects of silver-impregnated ventricular catheters.