title: Ethylene oxide's role as a reactive agent during sterilization: effects of polymer composition and device architecture.
abstract: Sterilization conditions need to be optimized to effectively neutralize the bioburden while using short exposure times for minimizing the changes in chemical composition, material properties and device architecture. Towards this goal, effects of ethylene oxide (EtO) exposure parameters such as time, temperature, humidity, and EtO concentration on the polymer properties were investigated by monitoring the changes in composition, and the morphology of different types of structures in a family of poly(ethylene glycol) (PEG)-containing tyrosine-derived polycarbonates. EtO was found to esterify the carboxyl groups present in the desaminotyrosyl-tyrosine groups. Sterilization under conditions more severe than those normally used reduced the glass transition temperature (Tg) and the molecular weight of the polymers, and the presence of PEG in the polymer enhanced this effect. Furthermore, electron micrographs showed that EtO sterilization cycle conditions, even those considered "mild," were found to damage the fragile structures such as those found in electrospun mats and porous scaffolds. Our study shows that the presence of EtO-susceptible groups, fusible architecture, and surface morphology should be taken into account in choosing the appropriate EtO sterilization conditions.
authors.affiliation: New Jersey Center for Biomaterials, Rutgers-The State University of New Jersey, Piscataway, New Jersey 08854, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Phillip
authors.forename: N Sanjeeva
authors.initials: NS
authors.lastname: Murthy
authors.forename: Durgadas
authors.initials: D
authors.lastname: Bolikal
authors.forename: Pallassana
authors.initials: P
authors.lastname: Narayanan
authors.forename: Joachim
authors.initials: J
authors.lastname: Kohn
authors.forename: Linda
authors.initials: L
authors.lastname: Lavelle
authors.forename: Stanko
authors.initials: S
authors.lastname: Bodnar
authors.forename: Kurt
authors.initials: K
authors.lastname: Pricer
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002850:Chromatography, Gel; D005027:Ethylene Oxide / Q000737:chemistry*; D005898:Glass; D009682:Magnetic Resonance Spectroscopy; D008422:Materials Testing; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000737:chemistry*; D016062:Porosity; D013242:Sterilization; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D011092:Polyethylene Glycols; D014443:Tyrosine; D005027:Ethylene Oxide