Trophowell

A method of testing drugs, the method comprising:

• providing a device,
• said device comprising:
• (i) a plurality of device walls that define an interior enclosure, said interior enclosure further comprising a hydrogel located within said device walls;
• (ii) a first and second capillary tube, wherein the open distal ends of said first and second capillaries extend into said interior enclosure and the first and second capillaries are in fluid communication with said interior enclosure, further wherein said first and second capillaries are configured to allow a biologically active substance and/or cells to transit said capillaries and be delivered to said interior enclosure, and said first and second capillaries are configured to be independently movable relative to said device walls to alter the distance between the distal ends of the first and second capillary relative to each other;
• and
• (iii) an optical port that allows for observations under microscope;
• flowing cells through said first capillary and into said interior enclosure,
• flowing a biologically active substance through said second capillary,
• wherein the distance separating the distal ends of the respective first and second capillaries is adjusted based on the diffusion coefficient of the biologically active substance flowing through the second capillary, the hydrogel contained in the interior enclosure, and the cells flowing through the first capillary.