The Potential of Suspended Chitosan Nanoparticles as a Surgical Irrigation Fluid.

In this study we sought to synthesize Chitosan nanoparticles (CS-NPs) and characterize their morphology, efficacy of inhibiting bacterial attachment, and efficacy in eradicating bacteria established on implantable hardware. CS-NPs possess desirable properties, including antibacterial properties in biofilm-mediated infections. CS-NPs were produced using ionic gelation and characterized via SEM imaging. Staphylococcus aureus was incubated with CS-NPs at various concentrations and compared to a 1% povidone-iodine with 1% H 2 O 2 control in 24 well plates. Stainless steel bone screws were placed in 6-well plates and inoculated with S. aureus. After 24 hours, the screws were transferred to one of three solutions (saline, 40mg/mL CS-NP, or 1% povidone-iodine with 1% H 2 O 2 ). Four screws from each group were vortexed in saline and plated. The remaining screw from each group was prepped and imaged to map the location of persistent bacteria. Synthesized CS-NPs had a mean diameter of 0.39±0.13μm and circularity of 0.87±0.05. The percent inhibition of bacterial attachment was 73% at 20mg/mL, 73% at 30mg/mL, 75% at 40mg/mL, 79% at 50mg/mL, and 78% at 60mg/mL. When compared to saline, the 40mg/mL CS-NP solution reduced bacteria on the screws by 76%. No bacteria were retrieved from the 1% povidone-iodine with 1% H 2 O 2 group. This study demonstrated that CS-NP solution effectively inhibited S. aureus bacterial attachment and was more effective than saline in eradicating bacteria from orthopedic hardware, suggesting that CS-NPs have potential for prevention and treatment of musculoskeletal infections as a component of an intraoperative surgical irrigation solution. This article is protected by copyright. All rights reserved.