Poster Y8 - A 3D printed platform for generating solid tumors and vessels to track tumor dynamics

Introduction: Organ-on-a-chip (OOC) technology replicates human tissue complexity in a miniaturized format using microfluidics, with photolithography as the standard fabrication method [1]. Despite its precision, photolithography is costly, time-consuming, and challenging for larger feature sizes as it reaches the millimeter (mm) scale [2]. Stereolithography offers a faster, reusable alternative for creating larger features, but drawbacks are transparency and imaging quality issues when casting polydimethylsiloxane (PDMS) off 3D printed molds. To overcome these limitations, we developed a reusable 3D printed platform for OOC studies, demonstrating its potential by generating arrays of solid tumors in collagen cavities and tracking tumor dynamics with live cell imaging.

Materials and

Methods: Device models of the 3D printed platform (well plate, channels, and PDMS spacers) were created in SOLIDWORKS and printed using the Formlabs 3+ stereolithographic printer using Clear V4 resin. Parts were then washed in isopropyl alcohol, dried, and coated with epoxy followed by curing overnight. The printed parts were cast with PDMS to generate channels, wells, and spacers. All parts were sterilized and PDMS channels were bonded to glass coverslips. Type I collagen was injected into the microfluidic chamber and molded around an acupuncture needle to generate an empty cavity, in which fluorescently labeled cells were subsequently seeded to generate solid tumors in 3D matrix, as previously described [3,4]. Four assembled devices on coverslips comprising 5 tumors each were placed within slots of the 3D printed plate and subjected to gravity-driven flow for long-term culture (14 days). OOCs were imaged using confocal microscopy to visualize tumor behaviors over time.

Results, Conclusions, and Discussions: Devices of the 3D printed platform (well plate, channels, and PDMS spacers) were designed in SOLIDWORKS and printed using the Formlabs 3+ printer using Clear V4 resin. Parts were washed in isopropyl alcohol, dried, and coated with epoxy followed by curing overnight. Printed parts were cast with PDMS to generate channels, wells, and spacers. Parts were sterilized and PDMS channels were bonded to glass coverslips. Type I collagen was injected into the microfluidic chamber and molded around an acupuncture needle to generate an empty cavity, in which cells were subsequently seeded to generate solid tumors in 3D matrix, as previously described [3,4]. Four assembled devices on coverslips comprising 5 tumors each were placed within slots of the 3D printed plate and subjected to gravity-driven flow for long-term culture (14 days). OOCs were imaged using confocal microscopy to visualize tumor behaviors over time. The work here provides an accessible platform for OOC generation and optical imaging, which can be applied toward the investigation of various complex diseases [4,1].

Acknowledgements (Optional): REFERENCES
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