Abstract

Versatile Synthetic Substrates For Cellular Assay Development and 3D Organoid Culture and Screening

Connie Lebakken, Chief Operating Officer, Stem Pharm, Inc.

Stem Pharm Inc. has developed a synthetic hydrogel platform that allows the design and optimization of substrates for cell expansion, differentiation and screening applications including 3D cell culture and organoid models. Through control of the substrate mechanical properties and adhesion ligand presentation, and utilizing chemistries that maintain cellular health and function, we provide cell-specific biomaterials for advanced cellular assay platforms and specialized cell expansion and differentiation applications.  For many applications, these hydrogels provide advantages over animal-derived biomaterials such as the Engelbreth-Holm-Swarm mouse sarcoma-derived products marketed as Matrigel®, Geltrex® and Cultrex®.  As one example, Stem Pharm has developed a vascular tubulogenesis hydrogel that enables high throughput screening (HTS) for vascular disruptors utilizing human umbilical vein endothelial cells (HUVEC) or iPSC-derived endothelial cells. Use of this hydrogel provides advantages over assay platforms that use Matrigel®, and similar products, that are challenging in an HTS workflow due to their temperature sensitivity and lot-to-lot variability. The Stem Pharm hydrogel platform is flexible for use in standard cell culture workflows, not requiring complex bioprinting methodologies and is suitable for co-culture and 3D organoid applications.  Organoids can be formed and maintained in multi-well plates while adhering to the hydrogel rather than growing en masse in suspension cultures.  This facilitates their use for toxicity or efficacy screening applications including those requiring imaging readouts.  In another example, a neural organoid model enabled by these hydrogels has been developed which produced multicomponent neural constructs with 3D neuronal and glial organization, organized vascular networks, and microglia with ramified morphologies (Schwartz et al (2015), PNAS 112, 12516-12521 and Barry et al (2017), Exp Biol Med 242, 1679-1689).  This model was utilized in a developmental neurotoxicity screen and demonstrated to be very reproducible both well-to-well and between independent experiments.