β-Tricalcium phosphate contained beaded-fiber scaffolds characterized by high early osteoinductive activity for...

The calcium phosphate component and surface topology of a scaffold are considered the two main factors that influence osteogenic differentiation. This research reports a one-step but effective scaffold preparation method that can regulate the morphology of nanofibers and control the distribution and release behavior of calcium phosphate nanoparticles (CaPs). Two beaded-on-string CaPs-loaded electrospun scaffolds (PT7.5 and PT4.5) with composite microstructures of microbeads and nanofibers were fabricated by adjusting the concentration of the electrospinning solution. The presence of the composite microstructure was conducive to the surface exposure and sustained release of bioactive components, which in turn could significantly promote the biomineralization and protein adsorption of the scaffold. A study of the human umbilical vein endothelial cells (HUVECs) and rat-bone marrow-derived mesenchymal stem cells (rBMSCs) revealed that cells cultured on scaffolds with composite microstructures (especially PT4.5) could enhance tube formation of the HUVECs and osteogenic differentiation of rBMSCs. The PT4.5 with significantly different microbead and nanofiber sizes presented the high potential to improve the early osteoinductive activity and angiogenesis of the CaPs-loaded electrospun scaffold and expand its advantage in bone regeneration.