Fig. 1. Methods of making organoids without Matrigel.

Replacing the undefined medium of Matrigel is a major goal of organoid culture. We will discuss three main alternative media: (a) decellularized extracellular matrix and other derived proteins, (b) synthetic hydrogels, which generally incorporate cell-adhesive domains or proteolytic degradation sites, and (c) gel-forming recombinant peptides. Adding multipotent cells to these matrices enables the growth of organoids, which are potentially applicable as transplants, drug-testing platforms, personalized medicine, and means to understand organ development.