How does gelation work in VitroGel?

The hydrogel formation starts when VitroGel is mixed with the cell culture medium.  The hydrogel molecules will interact with the ionic molecules, such as Ca2+ or Na+, from the cell culture medium to induce a matrix structure (hydrogel). For 3D culture operation, the hydrogel formation is in two stages: a) soft hydrogel formation and b) hydrogel stabilization.

1.  Soft hydrogel formation: The hydrogel formation process is slow when a small amount of cell culture medium is used. At this stage, the hydrogel is soft and possesses a shear-thinning and rapid recovering mechanical property, which makes the hydrogel injectable for in vivo. The slow hydrogel-forming process and the injectable property of the soft hydrogel create a time frame for easy hydrogel transfer from the mixing tube to the cell culture plate.



2.  Hydrogel stabilization: After soft hydrogel formation, adding additional cell culture medium on top of the hydrogel would allow more ionic molecules to penetrate the hydrogel matrix and further saturate the hydrogel cross-linking. A solid hydrogel would form during this process.