Dual-model biomanufacturing of porous biomimetic scaffolds with concentrated growth factors and embedded endothelial vascular channels for bone defect regeneration

In bone tissue engineering studies, establishing vascular networks plays a crucial role in enhancing bone graft repair strategies. While most engineered bones rely on host vascular invasion after implantation, this process is often slow. Therefore, exploring highly vascularized strategies may be beneficial to improving the success of tissue repair. This study aimed to construct bone scaffolds with biomimetic vascular networks using dual-model composite printing to promote angiogenic integration and enhance osteogenic repair. First, the polycaprolactone composite nano-tricalcium phosphate scaffold provided good mechanical properties and porosity and reserved space for the bionic vascular network. Meanwhile, researchers used concentrated growth-factorized gelatin methacryloyl hydrogel-loaded endothelial cells to construct a three-dimensional interoperable cavity structure, with multi-level vascular connectivity into a network diffusing throughout the scaffold. The slow release of biological signals from hydrogel enhanced the biological functions of scaffold acetogenesis and osteogenesis. The results of in vivo and in vitro experiments showed that the composite bionic scaffold enhanced angiogenesis, promoted integration with host vessels, and synergized nano-tricalcium phosphate osteogenesis induction, facilitating bone defect repair and regeneration. This vascularized tissue strategy was versatile and provided a valuable basis and positive insight for constructing large-scale vascularized bone grafts.