title: The effect of ethylene oxide sterilization on the surface chemistry and in vitro cytotoxicity of several kinds of chitosan.
abstract: The surfaces of three chitosan samples, differing only in their degrees of deacetylation and of carboxyethyl chitosan were chemically characterized by X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectroscopy, X-ray diffraction, and Fourier transform infrared, both before and after sterilization with ethylene oxide. Unexpected elemental ratios suggest that surface chemical modification occurred during the processing of the original chitin, with further surface modification on subsequent sterilization, despite previous reports to the contrary. Cell viability was evaluated by direct contact methyl thiazole tetrazolium and lactate dehydrogenase assays between the chitosan particles and A549 human epithelial cells, which demonstrated that the modifications incurred on sterilization are reflected in biocompatibility changes. All the samples were found to be biocompatible and nontoxic before sterilization and remained so subsequently. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
authors.affiliation: Department of Restorative Dentistry, University of Manitoba, Winnipeg, Manitoba, Canada, R3E 0W2.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: França
authors.forename: Doris A
authors.initials: DA
authors.lastname: Mbeh
authors.forename: Taraneh Djavanbakht
authors.initials: TD
authors.lastname: Samani
authors.forename: Canh
authors.initials: C
authors.lastname: Le Tien
authors.forename: Mircea A
authors.initials: MA
authors.lastname: Mateescu
authors.forename: L'hocine
authors.initials: L
authors.lastname: Yahia
authors.forename: Edward
authors.initials: E
authors.lastname: Sacher
keywords: biocompatibility; chemical modification; chitosan; cytotoxicological evaluation; ethylene oxide sterilization; surface characterization