Highly porous polymer matrices as a three-dimensional culture system for hepatocytes

Hepatocyte-based therapies (e.g., hepatocyte transplantation and extracorporeal support devices) may provide alternative therapies to treat patients with liver disease, but suitable approaches to localize these cells to a given location while maintaining liver-specific gene expression must be developed, The suitability of highly porous three-dimensional sponges fabricated from poly (L-lactic acid) [PLLA] as an hepatocyte culture system was evaluated in this study, Sponges were fabricated utilizing a particulate leaching technique, and were approximately 95% porous, with an average pore diameter of 180 mu m Hepatocytes seeded into these sponges adhered and remained viable for 14 days, However, the secretion rate of albumin from these cells, an indication of liver-specific gene expression, was low (approximately 6 pg/cell/day at day 1), and decreased steadily over the 14 days of the experiment, Coating sponges with collagen, and more preferably, immobilizing cells within the PLLA sponges with a collagen gel, led to enhanced cell survival and albumin secretion at all time points, These data suggest that porous PLLA sponges may provide a novel system for long-term culture of hepatocytes, and proper design of the system may allow the liver-specific gene expression of hepatocytes transplanted in these matrices to be enhanced. (C) 1997 Elsevier Science Inc.