Integrating pore architectures to evaluate vascularization efficacy in silicate-based bioceramic scaffolds

Pore architecture in bioceramic scaffolds plays an important role in facilitating vascularization efficiency during bone repair or orbital reconstruction. Many investigations have explored this relationship but lack integrating pore architectural features in a scaffold, hindering optimization of architectural parameters (geometry, size and curvature) to improve vascularization and consequently clinical outcomes. To address this challenge, we have developed an integrating design strategy to fabricate different pore architectures (cube, gyroid and hexagon) with different pore dimensions (similar to 350, 500 and 650 mu m) in the silicate-based bioceramic scaffolds via digital light processing technique. The sintered scaffolds maintained high-fidelity pore architectures similar to the printing model. The hexagon- and gyroid-pore scaffolds exhibited the highest and lowest compressive strength (from 15 to 55 MPa), respectively, but the cube-pore scaffolds showed appreciable elastic modulus. Moreover, the gyroid-pore architecture contributed on a faster ion dissolution and mass decay in vitro. It is interesting that both mu CT and histological analyses indicate vascularization efficiency was challenged even in the 650-mu m pore region of hexagon-pore scaffolds within 2 weeks in rabbit models, but the gyroid-pore constructs indicated appreciable blood vessel networks even in the 350-mu m pore region at 2 weeks and high-density blood vessels were uniformly invaded in the 500- and 650-mu m pore at 4 weeks. Angiogenesis was facilitated in the cube-pore scaffolds in comparison with the hexagon-pore ones within 4 weeks. These studies demonstrate that the continuous pore wall curvature feature in gyroid-pore architecture is an important implication for biodegradation, vascular cell migration and vessel ingrowth in porous bioceramic scaffolds.

Automated summary

Pore architecture in bioceramic scaffolds plays a crucial role in promoting vascularization efficiency. A study has developed an integrated design strategy to fabricate scaffolds with different pore architectures and dimensions. The gyroid-pore architecture showed accelerated ion dissolution and mass decay, leading to faster vascularization. In contrast, the hexagon-pore architecture exhibited lower vascularization efficiency, while the cube-pore architecture facilitated angiogenesis.