Reinforcing melt electrowritten elements with entangled multifibrillar strands for thin hydrogels with potential in bone resurfacing

Abstract

Osteonecrosis of the femoral head (ONFH) is a disease that affects young adults in their thirties to fifties, representing the progressive destruction of the hip bone caused by deficient vascularization. As the condition slowly leads to complete collapse of the femoral head, the conventional solution is total hip arthroplasty. Thin scaffolds consisting of fiber-reinforced hydrogels could be used to regenerate the affected bone surface, coupled with hip resurfacing for less invasive approaches. Melt electrowriting (MEW) was used to produce polycaprolactone (PCL) reinforcing elements for thin scaffolds, with four mesh densities and highly tunable mechanical properties. The influence of the MEW process parameters on the PCL filaments’ morphology was investigated using Design of Experiments to optimize their fabrication and obtain tailorable structures with entangled fiber morphology for increased contact surface with the hydrogel component. Uniaxial tensile tests were performed to investigate the difference in tensile properties of the entangled design versus the aligned counterparts, including the exploration of the mesh size effect. The microstructure and microstructural changes of the entangled meshes at uniaxial tensile deformation were explored using micro-computed tomography. Plasma treated meshes were embedded in gelatin methacryloyl/alginate hydrogels, developing reinforced composite scaffolds with potential for bone surface reconstruction.

Keywords

• Melt electrowriting (MEW)
• Polycaprolactone (PCL)
• Design of experiments (DoE)
• Osteonecrosis of femoral head (ONFH)
• Bone surface reconstruction