Primary human cardiac preadipocytes (Cell Applications, Sigma) were plated and began differentiation into mature adipocytes approximately 2 weeks before incorporation into systems. Cells were plated onto 70% isopropanol-sterilized 15 mm glass coverslips at a density of 90,000 cells/cs in Preadipocyte Growth Medium (Cell Applications, Sigma). Preadipocytes were cultured in growth medium for 1–3 days until confluent, and medium was replaced with Adipocyte Differentiation Medium (Cell Applications, Sigma). Differentiation of cells to mature adipocytes was designated when cells exhibited extensive lipid droplet accumulation.
For experiments in monoculture, treatment was performed in-plate, and cells remained in plate for testing/readouts. Prior to functional or endpoint assays, two-organ systems were disassembled and the organ modules were transferred to well-plates.