Effect of fulminant hepatic failure porcine plasma supplemented with essential components on encapsulated rat hepatocyte spheroids

The development of bioartificial liver (BAL) systems has required detailed information about the functional capabilities of cultured hepatocytes during blood or plasma passage. In this study we investigated the effects of porcine plasma and various supplements on the viability and function of adult rat hepatocytes in vitro. Primary rat hepatocytes cultured in porcine plasma supplemented with various substances showed albumin synthesis rates and viability equal to or higher than those of controls. Supplementation with calcium chloride, magnesium sulfate, trace elements, amino acids, insulin, and epidermal growth factor were essential to maintain viability and high albumin synthesis. Especially, trace elements showed significantly higher and longer albumin secretion.Isolated rat hepatocytes were cultured in Spinner flasks for 24 hours to form spheroids that were harvested and encapsulated with chitosan-alginate solution before transfer to the bioreactor in the BAL system. Encapsulated rat hepatocyte spheroids cultured with porcine plasma including trace elements showed higher viability (57%) than controls (40%) after 24 hours, with ammonia removal values of 30.92 μg/10⁶ cells versus the control 9.04 μg/10⁶ cells. After 24 hours of operation the urea secretion value of encapsulated rat hepatocyte spheroids cultured in porcine plasma in the presence versus absence of trace elements was 76.73 μg/10⁶ cells and 18.80 μg/10⁶ cells, respectively. We concluded that encapsulated hepatocyte spheroids in a packed-bed bioreactor operated with human plasma including trace elements enhanced cell viability and liver function as a bases for an in vivo clinical trial of the BAL system.