Robust Generation of ASC Spheroids for Use as 3D Cultures and in Bioprinted Tissue Models

Three-dimensional (3D) cell culture techniques have become a valuable tool to mimic the complex interactions of cells with each other and their surrounding extracellular matrix as they occur in vivo. In this respect, 3D spheroids are widely acknowledged as self-assembled cellular aggregates that can be generated from a variety of cell types without the need for exogenous material while being highly reproducible, easy to handle, and cost-effective. Furthermore, due to their capacity to be developed into microtissues, spheroids represent potential building blocks for various tissue engineering applications, including 3D bioprinting approaches for tissue model development. Adipose-derived stromal/stem cells (ASCs), due to their ease of isolation, multipotent nature, and secretory capacity, represent an attractive cell source employed in numerous tissue engineering studies and other cell-based therapy approaches. In this chapter, we describe two procedures for robust spheroid generation, namely the liquid overlay technique, either using agarose-coated 96-well plates or employing agarose-cast micromolds. Furthermore, we show, in principle, the generation of ASC spheroids with subsequent adipogenic differentiation and the spheroid generation using adipogenically differentiated ASCs, as well as the morphological characterization of generated spheroids.