High Throughput Morphological Screening Identifies Chemically Defined Media for Mesenchymal Stromal Cells that Enhances Proliferation and Supports Maintenance of Immunomodulatory Function

While mesenchymal stromal cell (MSC) therapies show promise for treating several indications due to their regenerative and immunomodulatory capacity, clinical translation has yet to be achieved due to a lack of robust, scalable manufacturing practices. Expansion using undefined fetal bovine serum (FBS) or human platelet lysate contributes to MSC functional heterogeneity and limits control of product quality. The need for tunable and consistent media has thus encouraged development of chemically defined media (CDM). However, CDM development strategies are rarely comprehensive nor considerate of a mediums impact on MSC therapeutic function. Standard practice often neglects high-level interactions of media components, such as growth factors, that are critical to MSC growth and function. Given that MSC morphology has been shown to predict their immunomodulatory function, we employed a high throughput screening (HTS) approach to elucidate effects of growth factor compositions on MSC phenotype and proliferation in a custom CDM. This approach led to the discovery and refinement of several formulations that enhanced MSC proliferation and demonstrated wide ranging impacts on MSC immunomodulation. Overall, this work reflects how our novel HTS approach serves as a generalizable tool for the comprehensive improvement of MSC manufacturing processes.