A hybrid electrospinning and electrospraying 3D printing for tissue engineered scaffolds

Purpose - Fabricating functionally graded scaffolds to mimic the complex spatial distributions of the composition, micro-structure and functionality of native tissues will be one of the key objectives for future tissue engineering research. This study aims to create a scaffold to mimic functionally-graded tissue using a hybrid process, which incorporated electrospun polycaprolactone (PCL) and electrosprayed hydroxyapatite (HA) in a simple pathway. Design/methodology/approach - The PCL and HA were dispensed simultaneously from different positions to form a layer on a rotational mandrel, and a gradient construct was achieved by adjusting dispensing rates of both materials. Findings - The morphology of scaffolds changed gradually from one layer to another layer with the change of the dispensing conditions of the two materials. The elemental distribution analysis revealed that C/Ca ratio linearly increased with certain dispensing rate ratio of PCL: HA. In addition, the thickness, mechanical properties (i.e. ultimate tensile stress and Young's modulus), surface roughness and water contact angle of each layer changed accordingly with the variation of dispensing rate of PCL and HA, and the diameter distributions of PCL fibres and HA particles did not vary significantly. Originality/value - This study showed the hybrid process has the potential to be used in fabrication of scaffold with functionally graded structure for tissue engineering applications, especially for mimicking the nature of the native 3D tendon-bone interface.