A cost-effective vessel-on-a-chip for high shear stress applications in vascular biology

The vascular endothelium is constantly subjected to hemodynamic forces, including tangential shear stress, which are crucial for maintaining vascular homeostasis. Pathological shear stress levels, such as those observed in pulmonary arterial hypertension (PAH) or atherosclerosis, disrupt this balance, driving vascular remodeling and endothelial dysfunction. Current microfluidic platforms for studying these conditions are limited by high costs, excessive reagent requirements, and non-physiological channel geometries. Here we introduce a novel microfluidic chip system, a Nylon Vessel-on-Chip (NVoC) which represents a cost-effective and straightforward fabrication platform that eliminates the need for specialized equipment and enables a physiologically relevant round channel geometry. The NVoC was fabricated using Polydimethylsiloxane (PDMS) and nylon threads, with surface activation achieved through polydopamine and collagen-I coating, enabling robust endothelial cell (EC) attachment and long-term culture. Immortalized endothelial colony-forming cells (iECFCs) and human umbilical vein EC (HUVECs) were used to optimize and validate the platform, demonstrating its compatibility with high shear stress conditions (up to 90 dyne/cm 2 ) and various molecular biology techniques, including RT-qPCR, Western blotting, and immunofluorescent staining. With fabrication costs six times lower than commercial alternatives and overall experimental costs reduced threefold, the NVoC offers the ability to expose endothelial cells to physiological and pathological shear stress levels in a reproducible, accessible, and scalable manner. Its versatility and affordability make it a valuable tool for investigating shear stress-related mechanisms in microvascular diseases, particularly PAH, with potential applications in drug discovery and translational research. • The Nylon Vessel-on-Chip (NVoC) enables physiologically relevant, round-channel vessel geometry using low-cost materials and reusable 3D-printed molds, reducing fabrication expenses by more than sixfold compared to commercial systems. • The NVoC reliably supports endothelial cell culture under physiological and pathological shear stress levels (up to 90 dyne/cm 2 ), without compromising cell morphology or viability, and is suitable for long-term dynamic flow experiments. • The system supports a broad range of molecular biology techniques, such as RT-qPCR, Western blot, immunofluorescence, enabling in-depth investigation of shear stress–regulated signal transduction pathways in endothelial cells.