Fig. 1.

Fabrication and characterization of manually deposited fibronectin fibers. (A) A pipette tip is submersed slowly into a concentrated solution (0.76 mg/mL) of fibronectin (Fn) and removed to generate polymerized Fn fibers that were deposited onto stretchable silicone sheets. (B) Differential Interference Contrast (DIC) and (C) fluorescence images of a fiber as it extends away from the droplet (upper-left corner) reveal a bundling behavior that is confirmed via (D) a Scanning Electron Micrograph taken along the length of the fiber. (E) DIC image of Human Foreskin Fibroblasts (HFFs) adhered to and oriented along the length of a fiber. (F) 3D-confocal microscopy reconstruction of a Human Umbilical Vein Endothelial Cell (HUVEC) spread on a manually deposited fiber: the cell is fluorescently labeled with a CellTrace™ Far Red dye (Invitrogen) and cultured for 1 h after seeding onto an Alexa Flour^® 488-labeled fiber. A dual-channel z-stack and Imaris™ software (Bitplane) were used to render the image shown. Grid marks represent 10 µm. The image is representative of cells on manually deposited fibers and confirms that cell adhesion occurs on the top and sides of a fiber but not onto the underlying substrate.