Scaffold-free human vascular calcification model using a bio-three-dimensional printer.

Morbidity and mortality rates associated with atherosclerosis-related diseases are increasing. Therefore, developing new research models is important in furthering our understanding of atherosclerosis and investigate novel treatments. Here, we designed novel vascular-like tubular tissues from multicellular spheroids composed of human aortic smooth muscle cells, endothelial cells, and fibroblasts using a bio-3D printer. We also evaluated their potential as a research model for Mönckeberg's medial calcific sclerosis. The tubular tissues were sufficiently strong to be handled 1 week after printing and could still be cultured for 3 weeks. Histological assessment showed that calcified areas appeared in the tubular tissues within 1 week after culture in a medium containing inorganic phosphate (Pi) or calcium chloride as the calcification-stimulating factors. Calcium deposition was confirmed using micro-computed tomography imaging. Real-time quantitative reverse transcription polymerase chain reaction analysis revealed that the expression of osteogenic transcription factors increased in calcified tubular tissues. Furthermore, the administration of Pi and rosuvastatin enhanced tissue calcification. The bio-3D printed vascular-like tubular structures, which are composed of human-derived cells, can serve as a novel research model for Mönckeberg's medial calcific sclerosis.