Researcher(s)
- Krish Patel, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- John Slater, Biomedical Engineering, University of Delaware
Abstract
Effect of Cancer Cell Density on Permeability of Microvessels
Krish Patel, Rishabh Singh, John H. Slater
Department of Biomedical Engineering, University of Delaware
The endothelium, a single layer of endothelial cells lining blood vessels, regulates blood flow and substance exchange between blood and tissues. Vascular leakage is tightly controlled to maintain homeostasis, but in diseases like cancer, endothelial barrier integrity is often compromised, leading to increased permeability and promoting metastasis. Initially viewed as passive barriers, endothelial cells are now understood to actively respond to cancer cells by downregulating junctional proteins. Specifically, cancer cell interaction reduces actin fibers in endothelial cells, creating tight junction gaps and facilitating cancer cell intravasation. To better study the endothelium’s role in metastasis, more advanced in vitro models are needed. Traditional 2D platforms like transwell assays fail to capture key cell–cell and cell–matrix interactions. Advances in microfluidics and biomaterials have enabled the development of biomimetic 3D endothelial models. Here, we present a new biofabrication approach to culture a 3D microvessel within a cancer hydrogel matrix and assess microvessel permeability as a function of cancer cell density. Hydrogels were formulated with 5% (w/v) PEG-PQ and 2.1 mM RGDS, photo-crosslinked using 3.0 mg/mL lithium phenyl-2,4,6-trimethylbenzoylphosphinate under UV light (365 nm, 10 mW/cm²) for 1 minute. The triple-negative breast cancer cell line MDA-MB-231 (p231) was encapsulated at either 1 or 5 million cells/mL. Human brain microvascular endothelial cells (hCMEC/D3) were used to form the vascular network. Microvessel fabrication involved: [a] polymerizing the p231-laden hydrogel in a PDMS mold with a removable FEP filament; [b] removing the filament post-crosslinking to form microchannels; [c] coating channels with fibronectin (100 µg/mL); and [d] perfusing with hCMEC/D3 cells (30 million cells/mL) after 24 h swelling in media. Permeability will be evaluated using fluorescent dextran (10 and 70 kDa), with dye leakage measured via fluorescence microscopy. We expect higher cancer cell densities to correlate with increased permeability due to compromised endothelial junctions.