Verteporfin

PS lumen devices were prepared as described above to create tubular void structures embedded in hydrogel. GFP fluorescent MDA-MB-231 cells were resuspended at 5 million cells/mL and loaded into the lumen structure as described above and left to adhere for 24 h. Verteporfin (Selleckchem, S1786, Pittsburgh, PA, USA), was dissolved at 25 mg/mL in DMSO, and later diluted 1:50,000 (to a final concentration of 500 ng/mL) in relevant media. Verteporfin solution was perfused through the lumen and incubated at 37 °C for 1 h. Thereafter, cells in the lumen were exposed to fluorescent light using a Nikon Eclipse Ti microscope and a 485/35 nm filter for 45 s. After the light activation of Verteporfin, cells were left in the incubator overnight. Viability was assessed via propidium iodide staining as described in subsequent sections, since cells were already fluorescently green, calcein was not required to stain live cells. Images were analyzed using ImageJ by plotting the fluorescence profile in three different region of interests (ROIs) in the image within the lumen (at the beginning, center and end of the lumen along the axis). The area under the curve was calculated and normalized to the highest value (among green and red) to demonstrate which of the fluorescence channels was more prevalent in each section (and ROI) of the lumen.