Enhanced retention of polymer physical characteristics and mechanical strength of 70:30 poly(L-lactide-co-D,L-lactide) after ethylene oxide sterilization

✍ Scribed by Anastasia J. McManus; Rodney C. Moser; Rhiannon B. Dabkowski; Kevin A. Thomas

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 351 KB
• Volume: 82B
• Category: Article
• ISSN: 1552-4973
• DOI: 10.1002/jbm.b.30737

✦ Synopsis

Abstract

This study examined the effect of ethylene oxide (EtO) and electron beam (e‐beam) irradiation on the properties of 70:30 poly(L‐lactide‐co‐D,L‐lactide). The effects of sterilization upon the polymer physical characteristics and strength retention of the material were examined, both initially and after being subjected to real time ageing. Commercially available 70:30 poly(L‐lactide‐co‐D,L‐lactide) material was fabricated into rectangular, cylindrical, screw, and sheet designs, and tested in compression, shear, or tension. Sterilization of 70:30 poly(L‐lactide‐co‐D,L‐lactide) by ethylene oxide had a nearly negligible effect on the physical properties of the polymer, regardless of specimen size or manufacturing technique. The molecular weight and inherent viscosity of the specimens decreased by ∼3% after sterilization by EtO. However, sterilization of 70:30 poly(L‐lactide‐co‐D,L‐lactide) by e‐beam irradiation resulted in immediate changes to some of the physical properties of the polymer. Specimens sterilized by e‐beam irradiation displayed an immediate decrease in inherent viscosity of ∼67% as compared to the respective nonsterile samples. The immediate decrease in inherent viscosity and molecular weight with e‐beam irradiation required ∼39 weeks of real time ageing of the EtO sterilized parts. At all time points investigated in the present study, the strength retention of the EtO sterilized devices equaled or exceeded that of the e‐beam irradiated samples. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007