3D-Microprinted PDMS-Based Microfluidic Vessels for Organ-on-a-Chip Applications

Microphysiological systems—also known as "organ-on-a-chip (OOC)" systems—hold considerable promise for applications including drug screening, disease modeling, and personalized medicine. A critical barrier to OOC efficacy, however, stems from manufacturing challenges that hinder the accurate recreation of 3D architectures and material properties of in vivo organ systems. To provide a new pathway to address these issues, here we leverage "Two-Photon Direct Laser Writing (DLW)" to 3D print physiologically relevant polydimethylsiloxane (PDMS) microvessels directly atop 3D microfluidic chips—fabricated via the "Vat Photopolymerization (VPP)" technique, "Liquid-Crystal Display (LCD)" 3D printing. Fabrication results revealed effective production of both interweaving and independent 3D microfluidic vessels with inner diameters (IDs) and wall thicknesses ranging from 80–100 μm and 5–10 μm, respectively, as well as pre-designed (i.e., as-printed) micropores with 5 μm diameters. Preliminary experimental results for MDA-MB-231 cells seeded within the porous microvessels revealed that the 3D PDMS system supported cell viability. In addition, pressure-vacuum experiments revealed that the permeation effects could be tuned to regulate the microenvironmental conditions internal and external to the porous microvessels. In combination, this work serves as a fundamental proof of principle for establishing entirely new classes of 3D microphysiological systems for diverse OOC applications.