title: Evaluating structural and microstructural changes of PDMS-SiO2 hybrid materials after sterilization by gamma irradiation.
abstract: PDMS-SiO2 hybrid materials obtained by sol-gel process have been extensively studied over the past years due to its promising biomedical applications namely as bone substitutes, catheters, and drug delivery devices. Regardless of the intended biomedical application, all these materials should go through a sterilization process before interfacing with a living structure. However, it is unclear whether they undergo structural and microstructural changes when subjected to sterilization by gamma irradiation. This paper addresses this issue by showing that a sol-gel processed biomaterial based on the PDMS-CaO-SiO2 hybrid system suffers only small structural changes when submitted to a radiation dose of 25kGy, the dose usually recommended to achieve a Sterility Assurance Level of 10(-6) when the natural contamination level and microorganism types cannot be calculated. The characterization was assessed by FT-IR, (29)Si-{(1)H} CP-MAS, thermal analysis (DTG), and SEM.
authors.affiliation: Department of Materials and Ceramic Engineering/CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: J Carlos
authors.initials: JC
authors.lastname: Almeida
authors.affiliation: Campus Tecnologico e Nuclear, IST, University of Lisbon, E.N 10, 2686-953 Sacavém, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Lancastre
authors.affiliation: Department of Materials and Ceramic Engineering/CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: M Helena
authors.initials: MH
authors.lastname: Vaz Fernandes
authors.affiliation: Campus Tecnologico e Nuclear, IST, University of Lisbon, E.N 10, 2686-953 Sacavém, Portugal.
authors.forename: Fernanda M A
authors.initials: FM
authors.lastname: Margaça
authors.affiliation: Campus Tecnologico e Nuclear, IST, University of Lisbon, E.N 10, 2686-953 Sacavém, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Ferreira
authors.affiliation: Department of Materials and Ceramic Engineering/CICECO, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: isabelmsalvado@ua.pt.
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Miranda Salvado
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D005720:Gamma Rays; D012822:Silicon Dioxide / Q000737:chemistry*; D013242:Sterilization
chemical_list: D004129:Dimethylpolysiloxanes; D012822:Silicon Dioxide
keywords: Gamma irradiation; Hybrid materials; Microstructure; Sterilization; Structure