Culture on Tissue-Specific Coatings Derived from α-Amylase-Digested Decellularized Adipose Tissue Enhances the Proliferation and Adipogenic Differentiation of Human Adipose-Derived Stromal Cells

While extracellular matrix (ECM)-derived coatings have the potential to direct the response of cell populations in culture, there is a need to investigate the effects of ECM sourcing and processing on substrate bioactivity. To develop improved cell culture models for studying adipogenesis, the current study examines the proliferation and adipogenic differentiation of human adipose-derived stem/stromal cells (ASCs) on a range of ECM-derived coatings. Human decellularized adipose tissue (DAT) and commercially available bovine tendon collagen (COL) are digested with alpha-amylase or pepsin to prepare the coatings. Physical characterization demonstrates that alpha-amylase digestion generates softer, thicker, and more stable coatings, with a fibrous tissue-like ultrastructure that is lost in the pepsin-digested thin films. ASCs cultured on the alpha-amylase-digested ECM have a more spindle-shaped morphology, and proliferation is significantly enhanced on the alpha-amylase-digested DAT coatings. Further, the alpha-amylase-digested DAT provides a more pro-adipogenic microenvironment, based on higher levels of adipogenic gene expression, glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity, and perilipin staining. Overall, this study supports alpha-amylase digestion as a new approach for generating bioactive ECM-derived coatings, and demonstrates tissue-specific bioactivity using adipose-derived ECM to enhance ASC proliferation and adipogenic differentiation.