3D printing of PCL‑based composite scaffolds coated with mesoporous bioactive glass nanoparticles (MBGNs) incorporating boron and molybdenum for ion‑assisted bone tissue engineering

A new family of composite scafolds based on polycaprolactone (PCL) and mesoporous bioactive glass nanoparticles (MBGNs) were 3D-printed. These
printed scafolds were further coated by boron and molybdenum doped MBGNs. The scafolds were characterized in terms of microstructure, hydrophilicity, bioactivity and cytocompatibility. The scafolds exhibited well-defned pore geometries characterized by layer-by-layer microscale struts. MBGNs coatings increased the
hydrophilicity of the PCL scafolds. A burst release of silicon within the frst 48 h (100 ppm cumulative) was observed, indicating the fast dissolution/degradation of MBGNs. In contrast, the release of other ions such as calcium, boron and molybdenum was found to be lower, which is associated with their lower doping levels in the MBGNs silica matrix. In vitro experiments showed that MBGNs (doped and non-doped) enhanced the adhesion and proliferation of MC3T3-E1 cells; these positive biological outcomes were correlated with the release and biological activity of inorganic ions. The results thus demonstrate the potential of the composite scafolds as suitable candidates for bone tissue engineering.