Bioinspired vascular structures via 3D printing and suspended microfluidics

Accurate modeling of the complex three-dimensional (3D) microarchitectures of in vivo vascular structures has remained a formidable challenge for medical and biological communities. Although many platforms have been developed to mimic vascular microgeometry, difficulties associated with recreating in vivo characteristics such as permeability and tortuosity has impeded progress. To address these issues, here we present a novel strategy that combines additive manufacturing or “3D printing” with suspended microfluidics to fabricate semipermeable, tubular structures with tortuous architectures. Specifically, the approach entails: (i) using PolyJet 3D printing to create a tubular framework comprising local microcurvature and global tortuosity, and then (ii) employing a suspended microfluidics technique to coat the framework with a porous, biocompatible cellular scaffold. Fabricated proof-of-concept tubular scaffolds exhibited inner radii on the order of 100 μm. Experimental results revealed tubular rupture pressures in the range of approximately 30-65 kPa. Seeding of human umbilical vein endothelial cells (HUVECs) within the tubule suggests that the presented work could be extended to better model the micro/mesoscale architectures of vascular systems for applications including drug discovery, disease modeling, and personalized medicine.