Effects of Defined and Undefined Extracellular Matrices on Human iPSC Morphology, Expansion, and Differentiation

Abstract

Human induced pluripotent stem cells (iPSC) have great potential as a cell source for regenerative medicine, drug discovery and disease modeling. The quality and consistency of iPSC culture is critical for basic research and clinical therapy development. To improve reproducibility and safety, there have been significant effort in developing fully controlled iPSC systems such as using defined xeno-free media and feeder free substrates such as basement membrane extracts (BME). IPSC are anchorage dependent cells whose survival, pluripotency, and differentiation potential are critically dependent upon extracellular matrix (ECM). BME is a soluble form of the basement membrane that contains undefined ratios of ECM proteins. Proteins such as human recombinant vitronectin (VN) and fibronectin (FN) pose an attractive alternative to BME and have been shown to support iPSC culture. IPSC attach to the ECM via integrin receptors which are linked to focal adhesions and the cytoskeleton. Depending on the nature of the substrate, different integrin receptors may be recruited to promote iPSC adhesion and activate various survival, mitotic or differentiation pathways. It is critically important to understand the influences that diverse substrates may have on iPSC colony morphology or differentiation potential. Identifying and characterizing a chemically-defined surface for culturing iPSCs will be paramount for establishing consistency in stem cell cultures. In this work, we report differences in human iPSC colony morphology when cultured on different ECM substrates. Subsequently, iPSC colonies on VN, FN, or BME were characterized by assessing cellular identities, cytoskeletal structure, integrin/FA signaling, and differentiation potential.

Embryonic & Induced Pluripotent Stem Cell Products

Cultrex Basement Membrane Extract and Extracellular Matrices

Integrins and Associated Molecules