The US is experiencing an epidemic rise in obesity [1] and related co-morbidities, such as type 2 diabetes. Epidemiological studies demonstrate that these co-morbidities are specifically correlated with visceral (intra-abdominal) fat deposition. To elucidate this association, an ideal model, human visceral adipocytes, must be made available to researchers. Zen-Bio, Inc. will address this need by developing a characterized, commercially accessible source of cultured human visceral preadipocytes. Preliminary data indicate that visceral preadipocytes are distinct from subcutaneous adipocytes, requiring individualized culturing techniques. Aim 1 of this proposal will seek to maximize visceral preadipocyte recovery from small solid tissue samples by improving mechanical and enzymatic dissolution of tissue and removal of contaminating cell types. Aim 2 will focus on expansion of the visceral preadipocytes to at least 20 million cells by developing growth factor cocktails and determining optimal seeding densities. Aim 3 will assess two parameters, advanced age of a donor or increased time post-mortem, for negative impact on total cell recovery, viability and/or growth characteristics. This Phase I SBIR concentrates on developing specialized techniques needed for culture of visceral preadipocytes. In Phase II we will focus on differentiating these cells into mature visceral adipocytes, followed by optimization of cell-based assays to effectively utilize these cells.