Q21 - Biomimetic Peritoneal Cavity-on-a-Chip for Studying Cancer Progression and Metastasis

Introduction: : Diseases of the peritoneal cavity, including ovarian and pancreatic cancers, are often diagnosed at late stages, with recurrence survival rates of only 3–6 months. A hallmark of these diseases is the spread of circulating cells through peritoneal fluid, where they adhere to mesothelial cells lining the cavity. Despite the known importance of mechanical forces—such as those caused by breathing, digestion, and movement—current models fail to capture how dynamic pressure influences these cell behaviors. This gap in understanding is largely due to the difficulty of imaging and manipulating the peritoneal environment in vivo.
To address this, we developed a novel pressure-responsive peritoneal cavity-on-a-chip (PCOC) platform that integrates both biochemical and mechanical components of the native peritoneum. The system comprises a fluidic device with a tunable pressure-regulating top layer, an elastic membrane mimicking peritoneal stiffness, a 3D collagen-filled cavity for co-culture of mesothelial and tumor cells, and a glass substrate enabling high-resolution live-cell imaging. This platform supports interstitial flow and programmable pressure waveforms to replicate physiological and pathophysiological conditions. It enables real-time visualization of tumor cell migration, adhesion, and mesothelial barrier disruption under varying mechanical stress.
Fabricated via epoxy-coated 3D printed molds, the system is low-cost, reproducible, and scalable, supporting widespread use across academic and clinical labs. The integration of fluidic and mechanical stimuli into a single platform enables investigation of mechanosensitive pathways, under biologically relevant conditions. By supporting the use of patient-derived serous fluid, the device also has direct implications for personalized diagnostics and therapeutics in women’s health and cancer biology.

Materials and

Methods: : We developed a PCOC platform using 3D printed molds for casting PDMS-based fluidic channels. SLA and FDM mold designs were CAD-modeled to produce millifluidic channels (1×1×20 mm) and paired reservoir wells. Molds were post-processed and coated with Janchun or XTC-3D epoxy, enabling reuse and enhancing channel smoothness and optical transparency. (Figure 1) Microscopy confirmed improved feature fidelity in PDMS replicas cast from epoxy-coated molds (Figure 1A–B). We validated mold compatibility across feature sizes down to 100 μm using fluorescent dye profiles (Figure 1C).
Type I collagen was injected into the PDMS channels and shaped into a cavity. LP9 mesothelial cells were seeded to form a biomimetic cell lining. OVCAR3 ovarian cancer cells were introduced under gravity-driven flow via post-sealed reservoirs or pump-driven systems (Figure 2B). Devices were mounted on a custom 3D printed imaging plate containing four open slots with top and bottom water reservoirs to prevent evaporation during long-term microscopy (Figure 2C–D). A modular PDMS lid enabled pressure actuation for simulating intraperitoneal waveforms (Figure 3D).
Fluorescence and brightfield imaging were used to track tumor cell adhesion, invasion, and aggregate formation. Confocal microscopy was employed to visualize multicellular architecture and mesothelial barrier integrity. This design allows parallel testing of multiple conditions and supports tuning of extracellular matrix, cell type, and mechanical parameters without modifying chip geometry.

Results, Conclusions, and Discussions:: Our pressure-responsive PCOC platform enables modeling of peritoneal metastasis under realistic mechanical and fluidic conditions, offering both scalability and physiological relevance. Using standard FDM and SLA 3D printing combined with epoxy post-processing, we produced molds that yield smooth, optically clear PDMS-based channels with strong adhesion to substrates and cell compatibility (Figures 1-2). Cross-sectional and top-down imaging of fluorescent dyes and molded features validated channel geometry down to 100 μm, and epoxy treatment proved essential for optical clarity.
The modular chip supported both gravity-driven and pressure-driven perfusion through a collagen-based 3D cavity. GFP-labeled LP9 mesothelial cells formed a cohesive monolayer on the collagen interface (Figure 3B). OVCAR3 cells were introduced via passive flow, and we observed single cells and clusters flowing and adhering throughout the cavities (Figure 3C). Importantly, the chip supported sustained co-culture and high-resolution confocal microscopy, revealing spatial organization of cells and real-time cell dynamics.
We further are able to use a programmable pressure regulator (Figure 3D) to apply pulsatile forces that mimic ascitic fluid dynamics. This configuration allows us to observe pressure-dependent changes in mesothelial barrier integrity, tumor migration patterns, and cell-cell interactions—suggesting early involvement of pressure-modulated pathways. The chip’s compatibility with live-cell time-lapse imaging enables real-time tracking of mechanoresponse, including future exploration of the Hippo/YAP pathway.
Altogether, this platform offers a powerful, low-cost method for studying cancer cell mechanics, metastasis, and therapy response under dynamic fluidic conditions. Its accessibility, modularity, and clinical relevance position it as a promising tool for mechanomedicine, drug screening, and personalized oncology applications.

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