The role of biomimetic scaffold structures on bone tissue regeneration

Introduction: Melt elctrospinning writing (MEW) enables the production of 3D printed scaffolds with a high degree of control over fibre deposition, pore size, pore geometry and fibre diameter. Materials & Methods: In this study we examined the effect of fiber architecture on (a) the
physical properties of 3D printed scaffolds and (b) osteoblast function both in vitro and in vivo. 3D printed MEW e-poly caprolactone (PCL) scaffolds with (1) increasing pore size along the
longitudinal axis from 250 to750 µm (gradient), (2) differing strut offset value (30%, 50%) and (3) uniform pore size (250, 500 and 750 µm) were assessed.
Results: The gradient and 250um uniform pore size scaffolds had superior physical properties such as higher bending modulus while higher levels of mineralization and expression of
osteogenic genes (osteocalcin and osteopontin) in response to osteogenic growth factors were demonstrated in osteoblasts cultured on the 50% offset and gradient scaffolds. In vivo using a rat calvarial defect model, significant bone in-growth through the gradient and 500um scaffolds was demonstrated by microCT 8 weeks post-implantation which was subsequently confirmed by
histological analysis.
Conclusion: These studies indicate that structural offset and gradient porosity scaffolds may be better constructs for bone tissue regeneration applications.