Figure 1.

An arrayable method for fabricating cell-embedded free-standing collagen I lumens. (Ai) Photographs of device setup and basic workflow for Method 1. (Aii) A rubber spacer was added to the 3D printed device to hold up the Teflon tubes on each post. F127 hydrogel seals small gaps so the collagen I does not leak through. (Aiii) The rack was submerged in phosphate buffered saline, and the tubes were pushed down to remove the collagen rings and dissolve F127. (Bi) Fluorescence image of primary human umbilical artery smooth muscle cells embedded in a collagen I ring. Cells are stained with calcein AM (live, green) and ethidium-homodimer I (dead, red). (Bii) Image of an array of 3 mm OD and 1 mm ID hydrogel rings in a 96-well plate.