Researcher(s)
- Krish Patel, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- John Slater, Biomedical Engineering, University of Delaware
Abstract
The endothelium regulates blood flow and nutrient exchange, maintaining a tightly controlled barrier under homeostasis. In diseases such as cancer, endothelial integrity becomes compromised, increasing vascular permeability and enabling metastasis. Cancer cells release soluble factors that actively alter endothelial cell behavior by downregulating junctional proteins and reorganizing actin stress fibers. These changes loosen tight junctions and facilitate transendothelial migration, a key step in both intravasation and extravasation. Since these interactions are dynamic, advanced 3D endothelial models are needed to monitor endothelial–cancer cell crosstalk in physiologically relevant environments. Traditional 2D transwell assays fail to capture essential cell–cell and cell–matrix interactions. Recent microfluidic and biomaterial advances enable fabrication of biomimetic 3D microvessels. In this work, a perfusable microvessel was generated within a cancer‑cell‑laden hydrogel to evaluate how breast cancer–secreted factors alter microvessel permeability. A proteolytically degradable PEG‑based hydrogel containing integrin‑binding sites supported metastatic growth of encapsulated MDA‑MB‑231 (p231) cells at 2 million cells/mL. Human brain microvascular endothelial cells (hCMEC/D3) were used to form the vessel lining. Microchannels were created by UV‑crosslinking the hydrogel around a 300 µm polymeric filament, which was removed to produce an open lumen. The channel walls were functionalized with methacrylated gelatin to promote endothelial adhesion and lumen formation. After a 24‑hour swelling period, endothelial cells were perfused through the channel to establish the microvessel. The hydrogel’s degradable nature enabled cancer‑driven matrix remodeling and direct interaction with the vessel. Permeability was quantified using 10 kDa fluorescent dextran, with transport analyzed through temporal fluorescence imaging and Fick’s First Law. The presence of cancer cells surrounding the microvessel is expected to increase permeability by disrupting endothelial junctions and reorganizing cytoskeletal and actin fiber structures, reflecting cancer‑induced endothelial barrier dysfunction.