Physicochemical study for characterization of lyophilized collagens irradiated with gamma radiation and for optimization of medical device manufacturing process

In this study different experimental models of lyophilized collagen samples (wound dressing medical devices) were irradiated at different doses ranging from 10 kGy to 100 kGy and tested versus control samples (unirradiated). The purpose of our study to obtain new data on the gamma irradiation effects on different lyophilized collagens, by combined analytical techniques (TG/DSC, FTIR, SDS-PAGE and ICP-MS), which can be used for product qualification and optimizing the medical device manufacturing process. SDS-PAGE allowed highlighting the parameters of interest for optimizing the extraction and purification process of collagen and for characterizing the final product. In normal irradiation conditions (room temperature and normal atmosphere), gamma irradiation causes significant breaks of the macromolecular chains in the collagen molecule. Thermal analysis results can be used for confirmation and/or quantification of the results obtained by SDS-PAGE. Irradiation leads to a decrease of molecular masses, which is not found in a decrease in the stability of the fibrillar network: the cleavage of collagen macromolecules may be compensated by the formation of new intermolecular bonds (increasing the cross-linking degree). FTIR results confirms the absence of significant changes regarding the chemical structure of the collagenous material subjected to irradiation and can be used in the characterization of the cross-linking induced by ionizing radiation, in correlation with thermal analysis parameters. ICP-MS determinations confirm the adequacy of medical use of collagen material and can identify the contamination induced by the manufacturing process. •SDS-PAGE highlights parameters for optimizing extraction and purification of collagen.•Thermal analysis (TA) confirms and quantify results obtained by SDS-PAGE.•FT-IR and Thermal analysis correlation can characterize collagen cross-linking.•ICP-MS confirms the adequacy of the use of collagen for pharmaceutical applications.•γ radiation decreases collagen helix stability but not stability of fibrillar network.