Enhanced Strength Retention of Bioresorbable Implants Sterilized by Ethylene Oxide (ETO)

摘要

Sterilization by ethylene oxide had a nearly negligible effect on the molecular weight and inherent viscosity of the polymer. The immediate decrease in IV or Mw observed with e-beam sterilization required approximately 39 weeks of ageing following ETO sterilization. At all time points, the strength retention of ETO devices equaled or exceeded that of the e-beam. The essential effect of the ETO sterilization was to decrease the molecular degradation and corresponding mechanical strength loss typically observed with this material when sterilized by e-beam. These results indicate that bioresorbable 70:30 poly(L-lactide-co-D,L-lactide) implants sterilized by ETO can maintain substantially more strength than if sterilized by e-beam, for periods exceeding that typically required for bony healing or fusion, with no difference in the biocompatibility or crystallinity of the polymer.