Culture of porcine hepatocytes: The dogma of exogenous matrix revisited

The use of exogenous matrices has been described as an essential component in securing the viability and functionality of hepatocytes in vitro whether cultured for extracorporeal devices or cell transplantation. Here we repor t on the in vitro culture of porcine hepatocytes in polystyrene tissue-cult ure flasks without exogenous matrices showing adequate attachment and viabi lity. Cell proliferation was evidenced by uptake of 5-bromo-2'-deoxyuridine , with peaks at Days 2 (19.7 +/- 8.5%), 15 (20.8 +/- 3.3%), and 35 (21.4 +/ - 0.3%). Detoxification capacity was assessed by determination of monoethyl glycinexylidide, a product of lidocaine metabolism (highest value 156.5 +/- 10.1 ng/ml at Day 4), and by diazepam clearance (maximum mum clearance 66. 2% at Day 6). Diazepam metabolite levels were highest at Day 4 both for tem azepam and oxazepam (6.5 +/- 0.1 and 0.10 +/- 0.01, respectively). These re sults suggest that the need for an exogenous matrix to achieve sustained pr oliferative activity and differentiated hepatocyte function should not nece ssarily be considered a sine qua non condition.