Evaluation of the sterilization effect on biphasic scaffold based on bioactive glass and polymer honeycomb membrane

The sterilization is a core preoccupation when it comes to implantable biomaterials. The most common in industry is the gamma sterilization; however, the radiation used in this method can induce modifications in the material properties. This study investigates the impact of such radiations on the physicochemical properties and biological toxicity of a new biomaterial based on a poly-l-co-d,l-lactide polymer honeycomb membrane and bioactive glass (BG), combined, to form an assembly (membrane/BG assembly). The investigated BGs are the S53P4, which is FDA approved and clinically used, and 13-93B20, a BG containing boron promising for bone regeneration. Infrared and photoluminescence measurements revealed that, upon irradiation, defects are created in the BGs molecular matrix. Defects were identified to be mainly non-bridging oxygen hole center and occur in higher proportion in the 13-93B20 making it more sensitive to irradiation compared to the S53P4. However, the irradiation does not significantly impact the structure of the BGs. On the membrane side, the molecular weight is divided by two resulting in a lower shear stress resistance. However, the membrane honeycomb topography does not seem to be impacted by the irradiation. In contact with cells, no toxicity effect was observed, and BGs keep their bioactive properties by releasing ions beneficial to the cell fate and with no influence on apatite precipitation speed. Overall, this study showed that, despite some impact on the physicochemical properties, the irradiation does not induce deleterious effect on the membrane/BG assemblies and is therefore a suitable method for the sterilization of this novel biomaterial.