Formation of Spheroidal Aggregates of Hepatocytes on Biodegradable Polymers Under Continuous-Flow Bioreactor Conditions*

作者：Joerg Matthias Pollok, Dietrich Kluth, Robert J. Cusick, H. Lee, Hirofumi Utsunomiya, Pengtao Ma, Róbert Langer, Christoph E. Broelsch, Joseph P. Vacanti · 发表于：European Journal of Pediatric Surgery · 年份：1998 · DOI：10.1055/s-2008-1071153 · 被引用次数：34 · 研究领域：3D Printing in Biomedical Research

Our laboratory has investigated heterotopic hepatocyte transplantation on biodegradable polymer matrices as an experimental treatment for end-stage liver disease. One of the limitations has been survival of sufficient cell mass after transplantation. We hypothesize that in vitro conditioning of cells within polymer matrices prior to implantation may increase hepatocyte survival and function. In this preliminary study we investigated the effect of continuous flow on hepatocytes and sinusoidal endothelial cells on poly-L-lactic acid (PLLA) discs in vitro. Highly porous PLLA discs were manufactured measuring 18 mm diameter by 1 mm thickness using previously described techniques. Hepatocytes were isolated from adult, male Lewis rats (200-300 g) using a two-step collagenase digestion. Sinusoidal endothelial cells were isolated using a two-step collagenase digestion, differential sedimentation, Percoll gradient centrifugation, and selective adherence. PLLA discs were seeded with hepatocytes alone or with co-cultures of hepatocytes and sinusoidal endothelial cells. Seeded discs were then secured within a flow bioreactor chamber and exposed to continuous flow of culture media at a rate of 20 ml/minute through the chamber. Seeded discs placed in static culture conditions served as controls. Specimens seeded with only hepatocytes were harvested at 24 hours, 48 hours, and 168 hours after seeding. Co-culture specimens were harvested after 168 hours. Specimens were viewed under phase-cont...