Park Jaesung, Li Yawen, Berthiaume François, Toner Mehmet, Yarmush Martin L, Tilles Arno W
Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Shriners Hospitals for Children and Harvard Medical School, Boston, MA 02114, USA.
Biotechnol Bioeng. 2008 Feb 1;99(2):455-67. doi: 10.1002/bit.21572.
Bioartificial liver (BAL) devices with fully functioning hepatocytes have the potential to provide temporary hepatic support for patients with liver failure. The goal of this study was to optimize the flow environment for the cultured hepatocytes in a stacked substrate, radial flow bioreactor. Photolithographic techniques were used to microfabricate concentric grooves onto the underlying glass substrates. The microgrooves served to protect the seeded hepatocytes from the high shear stresses caused by the volumetric flow rates necessary for adequate convective oxygen delivery. Finite element analysis was used to analyze the shear stresses and oxygen concentrations in the bioreactor. By employing high volumetric flow rates, sufficient oxygen supply to the hepatocytes was possible without an integrated oxygen permeable membrane. To implement this concept, 18 microgrooved glass substrates, seeded with rat hepatocytes cocultured with 3T3-J2 fibroblasts, were stacked in the bioreactor, creating a channel height of 100 microm between each substrate. In this bioreactor configuration, liver-specific functions (i.e., albumin and urea synthesis rates) of the hepatocytes remained stable over 5 days of perfusion, and were significantly increased compared to those in the radial flow bioreactor with stacked substrates without microgrooves. This study suggests that this radial flow bioreactor with stacked microgrooved substrates is scalable and may have potential as a BAL device in the treatment of liver failure.
具有功能完备的肝细胞的生物人工肝（BAL）装置有潜力为肝衰竭患者提供临时肝脏支持。本研究的目的是优化堆叠基质径向流生物反应器中培养肝细胞的流动环境。利用光刻技术在底层玻璃基板上微制造同心凹槽。这些微凹槽用于保护接种的肝细胞免受因充足对流氧输送所需的体积流率所引起的高剪切应力影响。使用有限元分析来分析生物反应器中的剪切应力和氧浓度。通过采用高体积流率，在没有集成透氧膜的情况下也能够向肝细胞充分供氧。为实现这一概念，将18个接种了与3T3-J2成纤维细胞共培养的大鼠肝细胞的微槽玻璃基板堆叠在生物反应器中，在每个基板之间形成100微米的通道高度。在这种生物反应器配置中，肝细胞的肝脏特异性功能（即白蛋白和尿素合成率）在灌注5天内保持稳定，并且与没有微槽的堆叠基质径向流生物反应器相比显著增加。本研究表明，这种具有堆叠微槽基板的径向流生物反应器具有可扩展性，可能有潜力作为治疗肝衰竭的BAL装置。
