HepaRG Self-Assembled Spheroids in Alginate Beads Meet the Clinical Needs for Bioartificial Liver.

ABSTRACT

In liver tissue engineering, cell culture in spheroids is now well recognized to promote the maintenance of hepatic functions. However, the process leading to spheroids formation is time consuming, costly, and not easy to scale-up for further use in human bioartificial liver (BAL) applications. In this study, we encapsulated HepaRG cells (precursors of hepatocyte-like cells) in 1.5% alginate beads without preforming spheroids. Starting from a given hepatic biomass, we analyzed cell differentiation and metabolic performance for further use in a fluidized-bed BAL. We observed that cells self-rearranged as aggregates within the beads and adequately differentiated over time, in the absence of any differentiating factors classically used. On day 14 postencapsulation, cells displayed a wide range of hepatic features necessary for the treatment of a patient in acute liver failure. These activities include albumin synthesis, ammonia and lactate detoxification, and the efficacy of the enzymes involved in the xenobiotic metabolism (such as CYP1A1/2). Impact statement It has been recognized that culturing cells in spheroids (SPHs) is advantageous as they better reproduce the three-dimensional physiological microenvironment. This approach can be exploited in bioartificial liver applications, where obtaining a functional hepatic biomass is the major challenge. Our study describes an original method for culturing hepatic cells in alginate beads that makes possible the autonomous formation of SPHs after 3 days of culture. In turn, the cells differentiate adequately and display a wide range of hepatic features. They are also capable of treating a pathological plasma model. Finally, this setup can easily be scaled-up to treat acute liver failure.