Organoids—cellular aggregates derived from stem or progenitor cells that recapitulate organ function in miniature—are of growing interest in developmental biology and medicine. Organoids have been developed for organs and tissues such as the liver, gut, brain, and pancreas; they are used as organ surrogates to study a wide range of questions in basic and developmental biology, genetic disorders, and therapies. However, many organoids reported to date have been cultured in Matrigel, which is prepared from the secretion of Engelbreth-Holm-Swarm mouse sarcoma cells; Matrigel is complex and poorly defined. This complexity makes it difficult to elucidate Matrigel-specific factors governing organoid development. In this review, we discuss promising Matrigel-free methods for the generation and maintenance of organoids that use decellularized extracellular matrix (ECM), synthetic hydrogels, or gel-forming recombinant proteins.
Kozlowski, Crook, and Ku review current state-of-the-art techniques in culturing and manipulating organoids without the use of EHS-tumor-derived matrix, the most popular of which is Matrigel by Corning. They cover organoid-based applications of different matrix types, ranging from natural sources (decellularized ECM, purified ECM proteins, polysaccharides), synthetic sources (e.g. PEG-based), and recombinant peptide-based systems.