Advancing tumor-on-a-chip technologies: a 3D-printed, PDMS-free biochip for breast cancer studies

Organ-on-a-chip (OoC) systems are microfluidic technologies that replicate human physiology and disease conditionsex vivo, offering a promising alternative to animal models in preclinical drug testing and fundamental biological studies. Traditionally, OoCs systems are fabricated using conventional soft-lithography techniques with polydimethylsiloxane (PDMS) primarily due to its excellent inherent properties, including gas permeability, optical transparency, and biocompatibility. However, PDMS presents several notable shortcomings, most its limited scalability, which have prompted the search for more rapid and scalable fabrication processes. In this study, we present a cost-effective, efficient, and rapid design, development, and prototyping process for a microfluidic tumor-on-a-chip (TOC) platform technology for applications in cancer research and drug screening. Specifically, we present a novel 3D-printed, closed-system TOC device (i.e. Biochip) featuring distinct yet interconnected tumor and stromal regions, separated by an array of trapezoidal microposts, and fabricated with high precision and fidelity. The proposed Biochip was fabricated utilizing vat polymerization with a biocompatible resin and was compared alongside a conventional PDMS-glass (PDMS-G) and PDMS-laminate (PDMS-L) TOCs to evaluate its biological outcomes. The fabricated Biochip supported closed-channel 3D cell culture for testing up to 5 d. Using two triple-negative breast cancer cells, namely SUM-159 and MDA-MB-231, we further assessed and cross compared cellular migration, viability, and morphology across the Biochip, PDMS-G, and PDMS-L platforms. Overall, this work establishes a 3D-printed Biochip as a robust, cost-effective, and time-saving alternative to PDMS-based OoC, and specifically TOC systems.