The effect of wicking fibres in tissue-engineered bone scaffolds

The major limitation of large tissue-engineered constructs used for bone regeneration is the lack of vasculature and, therefore, lack of transport of essential nutrients, chemical factors and progenitor cells. Research approaches to improve the transport properties of large scaffolds focus on using angiogenic factors and vasculogenic cells to create new vasculature; however, the slow rate of vessel formation and reliance on vessel self-assembly in these approaches is problematic. In this study, a novel approach has been proposed, using proprietary engineered 'wicking' fibres of non-circular cross-section that provide highly efficient transport for fluid and cells. The effect of wicking fibres on the movement of fluorescein isothiocyanate (FITC)-conjugated protein in a three-dimensional (3D) hydrogel system was analysed. The results indicated that the rate of diffusion of the fluorescent protein was greatly enhanced in hydrogels that contained wicking fibres in comparison to those that did not. The movement of progenitor cells along wicking fibres and round fibres was assessed. This study demonstrated that wicking fibres enhance the movement of critical growth factors and progenitor cells central for bone regeneration. The results suggested that the incorporation of wicking fibres into large tissue-engineered constructs may improve the transport of growth factors and progenitor cells essential for bone formation.