Perfusion bioreactor driven by osmotic pressure gradients

A bioreactor system, comprising a plurality of cylindrical well-plate inserts positioned inside wells of a well-plate, each insert having a top opening, a bottom opening, and a cylindrical wall,

• wherein each insert is divided into at least one printing well and at least one collection chamber,
• wherein the printing well is filled with a three-dimensional (3D) cell growth medium that comprises a plurality of hydrogel particles and a liquid cell culture medium, wherein the hydrogel particles are swelled with the liquid cell culture medium to form a granular gel,
• wherein the printing well is configured to provide unencumbered access to the 3D cell growth medium for 3D printing,
• wherein the collection chamber is filled with an absorbant material that is separated from the well of the well-plate by a filter material,
• wherein the absorbant material establishes an osmotic pressure gradient that draws the liquid cell culture medium from the well of the well-plate where the liquid cell culture medium permeates the 3D cell growth medium, through the filter material, and finally into the absorbant material of the collection chamber, and
• wherein the filter material has a porosity smaller than the size of the swollen hydrogel particles.