Embedded multimaterial bioprinting platform for biofabrication of biomimetic vascular structures

The advent of bioprinting technology into the tissue engineering field has permitted the attainment of complex-shaped tissue constructs with unprecedented degree of precision and reproducibility, promising for the highly demanded tissue substitutes including vascular grafts. However, most of the bioprinted vascular tissue substitutes still lack multicellular composition and hierarchical complexity of native blood vessels. In this study, a multimaterial bioprinting platform incorporating multiple-channel microfluidic printhead was combined with embedded bioprinting technique for the fabrication of vascular-like constructs. Three different bioink formulations targeting intimal, medial, and adventitial zones of the natural vascular tissues were sequentially extruded from the microfluidic channels of printhead into a hydrogel-nanoclay support bath in a controlled manner to reach the biomimicry of vascular tissues. The results demonstrated the successful deposition of three bioink compositions into distinct zones within hollow structures, which would provide an opportunity for the construction of functional vascular substitutes.