No abstract

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.

Council for their financial support, to the staff of the Atlas Computer SS ratory, Chilton, for their extremely efficient service, and to iiss P. Sage for reproducing the drawings included in this thesis with such great care,The Author is especially indebted to his wife for her tolerance and understanding during the preparation of the thesis, and for ae many long hours she spent typing the manuscript. Oi ONL Ee Nie Synopsis Acknowledgements Contents Notation CHAPTER INTRODUCTION Set Criticism of elastic design methods 132 Limitations of simple plastic design 2g) Proposed design method CHAPTER HISTORICAL REVIEW OF RELATED WORK BAe : 2.3(b) Frame instability 2 oth Recent design and analysis methods