The potential of suspended chitosan nanoparticles as a surgical irrigation fluid

• Published in: Journal of orthopaedic research 2024-01, Vol.42 (1), p.223-229
• Main Authors: Holmes, Miles D., Narro, Analisa J., Jones, Hugh L., Noble, Philip C., Ambrose, Catherine G.
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; biomaterials; cell and molecular imaging; Chitosan - pharmacology; infection; Nanoparticles; Povidone-Iodine - pharmacology; Staphylococcus aureus
• ISSN: 0736-0266; 1554-527X
• DOI: 10.1002/jor.25667

In this study, we sought to synthesize chitosan nanoparticles (CS‐NPs) and characterize their morphology, efficacy in 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 scanning electron microscope imaging. Staphylococcus aureus was incubated with CS‐NPs at various concentrations and compared to a 1% povidone‐iodine with 1% H2O2 control in 24‐well plates. Stainless steel bone screws were placed in six‐well plates and inoculated with S. aureus. After 24 h, the screws were transferred to one of three solutions (saline, 40 mg/mL CS‐NP, or 1% povidone‐iodine with 1% H2O2). 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 ± 0.13 μm and circularity of 0.87 ± 0.05. The percent inhibition of bacterial attachment was 73% at 20 mg/mL, 73% at 30 mg/mL, 75% at 40 mg/mL, 79% at 50 mg/mL, and 78% at 60 mg/mL. When compared to saline, the 40 mg/mL CS‐NP solution reduced bacteria on the screws by 76%. No bacteria were retrieved from the 1% povidone‐iodine with 1% H2O2 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 the potential for prevention and treatment of musculoskeletal infections as a component of an intraoperative surgical irrigation solution.