Microgel particles for use in 3D printing and 3D cell growth medium and related compositions, systems, and methods

A three-dimensional cell growth medium, the three-dimensional cell growth medium consisting of:

• a plurality of microgel particles, wherein each of the plurality of microgel particles consists of a crosslinked polymeric network, and wherein the crosslinked polymeric network consists of:
• low charge density polymer molecules, wherein each of the low charge density polymer molecules consists of a first set of neutral monomer units derived from acrylamide and a second set of charged monomer units derived from methacrylic acid, wherein an average spacing between the charged monomer units is greater than the Bjerrum length;
• and
• a crosslinker;
• wherein a molar ratio of the first monomer to the crosslinker present in the solution is between 20:1 and 200:1;
• and
• a liquid cell culture medium, wherein the plurality of microgel particles swell with the liquid cell culture medium to form a three-dimensional granular gel;
• and
• wherein the three-dimensional cell growth medium is a yield stress material.