Speaker
Description
A new-generation of synthetic bone scaffold is tailored using a bricks-and-mortar approach from bioactive glass nanoparticles BGNps (SiO2-CaO-P2O5 doped with metal ions, the bricks), and customized polymers (PLA, poly (lactic acid), the mortar). Used as synthetic implants for substitutive and regenerative therapies targeting mandibular osteoradionecrosis (ORM), they must promote bone formation and cell adhesion, while exhibiting high porosity, adequate mechanical strength, and pro-angiogenic coupled with antibacterial properties. Freeze-casting solutions of BGNps and PLA derivatives can result in hybrid nanocomposite scaffolds1, with a multi-scale porosity, offering improved mechanical properties and proper auto-catalytic degradation.
To shed light on the mechanisms behind the formation of the hierarchical structure of these scaffolds, the synthesis of BGNps derived from Stöber silica was studied using in-situ SAXS at synchrotron facilities (ID02@ESRF2 and SWING@SOLEIL). The SAXS data revealed the preorganization of the particles in solution prior to freeze-casting.
Subsequently, thanks to a custom-built sample chamber, fast X-ray phase-contrast tomography operando experiments were performed using synchrotron beams (ID19@ESRF). They allowed to follow the controlled growth via a freeze-casting process of centimeter-cubed scaffolds made from nanoparticles (bricks) and polymers (mortar), at high resolution. We pictured the fabrication process from the initial suspension of nanoparticles to the finalized porous material, obtained via lyophilization that was also studied operando with X-ray tomography.
