(149f) A Comparison of Two Dimensional Monolayer and Three Dimensional Spheroid Adipocyte Cultures

According to the Center for Disease Control and Prevention, 72.5 million adults in the United States are classified as obese, with the annual mortality rate exceeding 300,000. In order to effectively treat this disease, obesity must be better understood at the cellular level with respect to metabolic state and environmental stress; however, current two-dimensional (2-D) in vitro cell culture methods do not represent the in vivo adipose tissue appropriately due to absence of complex architecture and cellular signaling. Conversely, 3-D in vitro cultures have been reported in the literature to have optimal results mimicking the adipose tissue in vivo. In previous studies, our laboratory created 3-D spheroid hepatocyte constructs when cells were cultured on tissue culture polystyrene (TCPS) culture plates coated with elastin-like polypeptide (ELP) coupled to polyethyleneimine (PEI). The aims of this study were to examine the efficacy of the ELP-PEI conjugate toward creating a 3-D preadipocyte culture system, and to study their differentiation and maintenance process in physiologically-relevant microenvironments when subjected to various concentrations of nutritionally relevant free fatty acids with respect to total DNA content, cell viability, and intracellular triglyceride accumulation. Our results showed that 3T3-L1 preadipocytes cultured on the ELP-PEI surface formed 3-D spheroids within 72 hours, whereas the cells cultured on unmodified TCPS remained in monolayer configuration. Significant statistical difference was discovered between the 3-D spheroid and 2-D monolayer culture with respect to the DNA content and triglyceride accumulation, indicating differences in cellular response. Results indicated that the 3-D culture may be a more sensitive modeling technique for in vitro adipocyte culture and provides a platform for future evaluation of 3-D in vitro adipocyte culture. This outcome may prove advantageous for more rapidly promoting a differentiated phenotype in adipose cell cultures for investigating the influence of exogenous drugs and nutrient treatments on a mature cell population over a shorter in vitro experimental period.