Development of a New Bioartificial Liver Support System Using a Radial-flow Bioreactor

Abstract

There is an increasing number of patients with severe liver disease that requires whole organ transplantation or living-related split liver transplantation. This has resulted in a shortage of donor organs, which is particularly problematic and still awaits resolution. Bioartificial liver (BAL) support systems have been developed with the aim of supporting patients with life-threatening liver disease until their liver recovers. Here, we describe a high performance three-dimensional rat hepatocyte culture system using a radial-flow bioreactor (RFB) with a polyvinyl alcohol (PVA) membrane as a small-scale BAL support system. Hepatocytes from male Sprague-Dawley rat livers were isolated and divided into two groups as follows. Group A: isolated hepatocytes were maintained in culture medium as controls; and group B: isolated hepatocytes were injected into the medium chamber of the RFB-PVA culture system. Sampling was carried out every 48 h to analyze the concentrations of ammonia and albumin in the medium. Light and electron microscopic examination of hepatocytes explanted from the PVA membrane was also performed. Albumin production and urea synthesis by cells in group B were both significantly higher than in group A. Hematoxylin-Eosin staining of the cells in group B showed that three-dimensional cell masses were attached to the PVA membrane. It also showed that the cells were stably proliferating in the porous spaces of the PVA. Scanning electron microscopic images of group B also showed clusters of hepatocytes attached to the PVA membrane. Hepatocyte clusters growing in the RFB-PVA culture system retained their biological function and were stable in the porous spaces of the PVA membrane. This cell culture system may be useful for the development of new BAL support systems.