Microengineered tissue barrier system

A method of culturing cells in a microfluidic device, the method comprising:

• a step of assembling a microfluidic device, wherein the microfluidic device is comprises an insert comprising a first central channel;
• a base comprising a second central channel, a third side channel, and a fourth side channel;
• and a porous membrane positioned between the insert and the base, wherein the insert is detachable from the base;
• a step of injecting second cells into the second central channel and then inverting the microfluidic device and culturing them;
• a step of injecting hydrogel comprising third cells into the second central channel and then culturing them;
• and
• a step of inverting the microfluidic device and then injecting first cells into the first central channel and culturing them.

A method of simulating an organ or a body part in a microfluidic device, wherein the microfluidic device is comprises an insert comprising a first central channel;

• a base comprising a second central channel, a third side channel, a fourth side channel, a first fluid reservoir, and a second fluid reservoir;
• and a porous membrane positioned between the insert and the base, wherein the insert is detachable from the base, wherein the method comprises
• a step of perfusing a first fluid through the first central channel;
• and
• a step of injecting a second fluid into the first fluid reservoir to sequentially reach the third side channel, the second central channel, the fourth side channel, and the second fluid reservoir.