Comparative assessment of chemical and gamma-irradiation procedures for implantable glucose enzyme electrodes.
Chemical and gamma-irradiation sterilisation were examined in this study for implantable needle electrodes. Exposure to isopropyl alcohol (IPA) led to response elevation, but time-dependent exposures up to 30 min variously to chlorhexidine, H2O2, HCl, HCl/IPA, and alcoholic iodine/potassium iodide, all caused substantial time-dependent response degradation. Sterility was not assessed for such electrodes. High dose (30 KGy) gamma-irradiation also compromised sensor response, with exposed electrodes exhibiting approximately 30% reduction in response, comparable in magnitude to 10 min exposure to chemical sterilisation. However, a lower dose (25 KGy) gamma-irradiation was well tolerated and subsequent microbiological testing (following contamination with Streptococcus epidermidis and Staphylococus aureus) proved device sterility with no culture growth following 7 days incubation at 37 degrees C in brain heart infusion medium.
Ahmed
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S
Section of Clinical Biochemistry, Hope Hospital, Salford, UK. sahmed@fsl.ho.man.ac.uk
Rigby
G P
GP
Crump
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P
Vadgama
P M
PM
D019840:2-Propanol; D015374:Biosensing Techniques / Q000295:instrumentation*; D003470:Culture Media; D004202:Disinfectants; D005720:Gamma Rays; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase; D019736:Prostheses and Implants; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D013242:Sterilization / Q000379:methods*; D013291:Streptococcus / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects
D003470:Culture Media; D004202:Disinfectants; D005949:Glucose Oxidase; D005947:Glucose; D019840:2-Propanol