Effects of gamma irradiation and periodate oxidation on the structure of dextrin assessed by mass spectrometry

Abstract

Sterilization of biomaterials by gamma irradiation should not change its structure, since this may affect also its bioactivity. In this work, dextrin and periodate-oxidized dextrin (ODEX), both irradiated and non-irradiated, were hydrolysed by -amylase and the obtained oligosaccharides were fractionated by ligand-exchange/size exclusion chromatography and analyzed by matrix-assisted laser desorption/ionization (MALDI-MS) and electrospray ionization (ESI-MSn) mass spectrometry. This allowed the identification of structures formed during partial periodate oxidation, which displayed aldehyde groups in different positions of dextrin backbone, according to the type of residue which was oxidized. Importantly, gamma irradiation did not structurally change either dextrin or ODEX, showing that it can be used as suitable terminal sterilization method of these materials for biomedical applications. To our best knowledge, this is the first report using MS-based techniques to evaluate the effects of partial periodate oxidation and of gamma irradiation on polysaccharides and, in particular, on dextrin and its oxidized form.