Solvent-free melt-electrowriting of polycaprolactone-bioceramic composites

With increasing surgical cases for bone reconstruction, there is a rising need for advanced synthetic graft materials. In this paper, a novel pipeline for fabricating polycaprolactone (PCL)/bioceramic scaffolds was used to produce micron-fibre composite scaffolds comprising either 25 wt% 45S5 bioglass/45K PCL or 25 wt% molybdenum-doped bioglass/45K PCL (MoBG/PCL). Cryomixing was shown to be an effective method for evenly dispersing high concentrations of finely milled bioceramic particles into PCL without the need for chloroform solvents. The resulting composites had sufficiently low viscosity at 120 °C to be printed using melt electrowriting (MEW). The addition of bioceramic particles into PCL increased the elastic modulus and dramatically reduced the elongation at break. MEW scaffolds printed from a MoBG/PCL composite were shown to effectively support osteoblast cell growth. The cells on MoBG/PCL constructs displayed greater metabolic activity and DNA concentration after 7 days in culture relative to constructs made from unmodified PCL. Concentrated MoBG/PCL composite scaffolds may be a promising pathway for advanced bone tissue scaffolds.