EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Some bone diseases require the use of biomaterials that facilitate the natural bone regeneration processes. In this context, the use of 3D scaffolds based on mesoporous bioactive glasses (MBGs) improved with therapeutic ions, biologically active molecules and mesenchymal cells (MSCs) is a remarkable strategy to improve bone repair. In this study, the osteogenic ability of ZnO-enriched MBG scaffolds loaded or not with osteostatin (OST) and autologous MSCs was evaluated after implantation in New Zealand osteoporotic rabbits. Cylindrical meso-macroporous scaffolds with composition 76SiO2-15CaO-5P2O5-4ZnO (mol-%) (4ZN) were obtained by rapid prototyping and then coated with a gelatin layer for easy handling and to favor the release to medium of ions and biomolecules in the scaffolds. Then, 4ZN was loaded with OST, by soaking in a 100 nM peptide solution and seeded at 15.104cells/scaffold with autologous MSCs obtained from bone marrow of donor femur rabbits. Bone defects 7.5 mm diameter, 12 mm depth, were drilled in distal femoral epiphysis and filled with 4ZN or 4ZN + MSC + OST. Rabbits were sacrificed at 6 and 12 weeks extracting the distal third of bone specimens for microtomography (µCT) and histological analyses. 4ZN + MSC + OST scaffolds exhibited improved bone repair ability compared to 4ZN scaffolds in histological sections stained with Von Kossa and Goldner's trichrome. These positive results were confirmed by µCT determinations in both trabecular and cortical bone at 6 and 12 weeks. Trabecular bone volume density (BV/TV), trabecular number and cortical thickness parameters were significantly improved by 4ZN + MSC + OST scaffolds compared with 4ZN scaffolds. In this regard, trabecular separation was also decreased in presence of 4ZN + MSC + OST materials. Our in vivo findings suggest the interest of these MBGs-based systems loaded with OST and decorated with autologous MSCs to improve bone repair in the clinical practice.