Collagen Based Bioactive Electrospun Scaffolds for Bone Tissue Engineering

Most natural tissues contain substantial amounts of collagen, a natural polymer. Bone consists of Type I collagen reinforced with approximately 40vol% bone mineral, a version of hydroxyapatite (Ca10(PO4)6(OH)2). The aim of this project is to optimise the production of a bioactive, porous scaffold based on dual core electrospinning. This will be used to coat each fibre of a slowly degrading ductile polymer, with a more bioactive outer layer, attracting cells to accelerate bone formation. The inner fibre core will be polycaprolactone, the outer layer clinical grade Type I collagen to be either mineralised in vitro or manufactured containing HA. Natural collagen provides a framework of extracellular matrix (ECM) for tissues. Collagen is substantially more bioactive and biocompatible than most polymers, but the supply system is complex to ensure clinical grade material and needs careful processing to ensure controlled degradation of the materials/device produced, for this project will be supplied by Collagen Solutions Ltd. Additionally, peptides have been employed to mimic natural tissue fibrous structures of the extra cellular matrix. Synthetic ionic self-assembly oligo-peptides (iSAP) have the ability to drive differential cell responses by specific ligand-receptor interaction. In this study we will functionalise the scaffold surfaces with a novel iSAP. Composite optimisation will be based on mechanical properties, principally strength and ductility, followed by assessment of biocompatibility and bioactivity with further optimisation.