Coupled osteogenesis and angiogenesis on 3D-printed highly porous PCL/magnesium/laponite nanocomposite scaffold

3D-printed scaffolds are crucial in bone tissue engineering, providing a bioactive porous network for osteogenesis. However, their limited angiogenesis and mechanical strength poses challenges for effective bone repair. In this study, a 3D-printed scaffold based on polycaprolactone (PCL) containing magnesium particles (Mg) and laponite nanoparticles (LAP) loaded with pre-osteoblastic cells (MC₃T₃-E₁) was developed to simultaneously improve mechanical properties, and exhibit coupled osteoblastic differentiation and vascularization. Adding Mg and LAP particles to PCL increased cell viability by 21% and 10% for scaffolds containing Mg (PM) and Mg-LAP (PML), respectively. The hierarchical 3D structure was investigated by scanning electron microscopy, while the surface properties and the structural analysis were studied by FTIR, DLS, XRD, and wettability tests. The PM and PML showed 20% and 60% enhancement in Young's modulus as compared to the P scaffold, i.e., remarkably in the range of natural bone. Noticeably, adding Mg and LAP increased the alkaline phosphate enzyme activity of pre-osteoblastic cells by 28-fold and 20-fold in comparison with the P scaffolds and non-treated control samples. Moreover, PML printed scaffold showed significantly higher vascularization compared to P scaffolds in chorioallantoic membrane (CAM) assay. The 3D-printed scaffolds developed in this study demonstrated coupled osteogenesis and angiogenesis, paving the way for innovative biomaterials in bone tissue regeneration.