Coaxial 3D bioprinting of organ prototyps from nutrients delivery to vascularization
Hamed Ramezani, Luyu Zhou, Lei Shao, Yong He
Abstract
Vascular networks inside organs provide the means for metabolic exchange and adequate nutrition. Similarly, vascular or nutrient networks are needed when building tissue constructs >500 µm in vitro due to the hydrogel compact pore size of bioinks. As the hydrogel used in bioinks is rather soft, it is a great challenge to reconstruct effective vascular networks. Recently, coaxial 3D bioprinting was developed to print tissue constructs directly using hollow hydrogel fibers, which can be treated as built-in microchannels for nutrient delivery. Furthermore, vascular networks could be printed directly through coaxial 3D bioprinting. This review summarizes recent advances in coaxial bioprinting for the fabrication of complex vascularized tissue constructs including methods, the effectiveness of varying strategies, and the use of sacrificial bioink. The limitations and challenges of coaxial 3D bioprinting are also summarized.