Evaluating structural and microstructural changes of PDMS –SiO₂ hybrid materials after sterilization by gamma irradiation

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 25 kGy, 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, ²⁹Si–{¹H} CP-MAS, thermal analysis (DTG), and SEM. - Highlights: • Hybrid PDMS–SiO₂ materials were subjected to sterilization by γ-irradiation. • Materials suffer only small structural changes when irradiated. • Characterization was assessed by FT-IR, ²⁹Si-{¹H} CP-MAS, DTG and SEM