用猪肝细胞型混合生物人工肝支持系统治疗肝衰竭的初步研究

目的 对培养猪肝细胞型混合生物人工肝支持系统治疗肝衰竭的可行性进行初步评价。方法 采用自行研制的以新生实验小型猪肝细胞为基础的混合生物人工肝支持系统，对5例慢性重型肝炎患者进行体外人工肝支持，综合评价其临床疗效和安全性。结果 5例患者经混合人工肝支持后，肝衰竭均得到不同程度的控制，表现为临床症状和肝衰竭相关指标好转，肝性脑病改善。最终2例好转出院，1例经肝移植存活，2例 死亡，死亡原因与不良反应无关。结论 猪肝细胞型混合生物人工肝系统可用作重型肝炎肝衰竭的辅助支持和治疗。     

肝细胞培养过程中酸碱度和溶解氧的关联控制

目的在生物型人工肝支持系统(BAL)中,设计一种能够精确控制溶解氧(D0)与酸碱度(pH)的控制方案.方法根据肝细胞培养过程中所需要的物料衡算,采用比例积分(PI)算法结合开关量控制、预测控制等方案,通过工控机构建关联控制系统,使得D0与pH的值相互关联.结果DO控制范围0%～200%,精度达到±5%;pH控制范围6～8,精度达到±0.05.结论经实验证实,本控制方案工作稳定,无静态误差,解决了培养过程中DO与pH相互影响的问题,可用于BAL中对肝细胞培养环境的控制.     

非生物人工肝在重型肝炎患者过渡肝移植中的应用价值

目的　评价非生物人工肝对重型病毒性肝炎 (重型肝炎 )患者等待肝移植的过渡支持作用与价值。方法　采用血浆置换和血浆吸附两种非生物人工肝支持疗法 ,对 8例拟定肝移植的中晚期重型肝炎患者进行人工肝过渡支持。结果　 8例重型肝炎患者经人工肝支持 ,4例肝衰竭得到较好的控制 ,4～ 13d后成功等到供肝。另 4例肝衰竭控制不明显 ,病情呈进行性加重 ,在待肝过程中 (人工肝支持后 3～ 8d)死亡。结论　非生物人工肝对等待肝移植的重型肝炎患者有一定的过渡支持作用 ,能否最终成功过渡与患者肝衰竭程度、并发症及待肝时间密切相关。     

New insights into the effects of biomaterial chemistry and topography on the morphology of kidney epithelial cells

Increasing incidence of renal pathology in the western world calls for innovative research for the development of cell‐based therapies such as a bioartificial kidney (BAK) device. To fulfil the multitude of kidney functions, the core component of the BAK is a living membrane consisting of a tight kidney cell monolayer with preserved functional organic ion transporters cultured on a polymeric membrane surface. This membrane, on one side, is in contact with blood and therefore should have excellent blood compatibility, whereas the other side should facilitate functional monolayer formation. This work investigated the effect of membrane chemistry and surface topography on kidney epithelial cells to improve the formation of a functional monolayer. To achieve this, microtopographies were fabricated with high resolution and reproducibility on polystyrene films and on polyethersulfone‐polyvinyl pyrrolidone (PES‐PVP) porous membranes. A conditionally immortalized proximal tubule epithelial cell line (ciPTEC) was cultured on both, and subsequently, the cell morphology and monolayer formation were assessed. Our results showed that L‐dopamine coating of the PES‐PVP was sufficient to support ciPTEC monolayer formation. The polystyrene topographies with large features were able to align the cells in various patterns without significantly disruption of monolayer formation; however, the PES‐PVP topographies with large features disrupted the monolayer. In contrast, the PES‐PVP membranes with small features and with large spacing supported well the ciPTEC monolayer formation. In addition, the topographical PES‐PVP membranes were compatible as a substrate membrane to measure organic cation transporter activity in Transwell® systems. Copyright © 2016 John Wiley & Sons, Ltd.     

Maintenance of integrity and function of isolated hepatocytes during extended suspension culture at 25°C

Abstract: Isolated hepatocytes in suspension provide a number of advantages for use in bioartificial liver device, however, poor stability of this cell preparation at physiological temperatures is an apparent barrier preventing their use. We therefore investigated the integrity and differentiated function of isolated rat hepatocytes under conditions of mild hypothermia. Isolated hepatocytes were suspended in a bicarbonate buffered saline medium, supplemented with glucose and bovine serum albumin (BSA), and maintained for 48 h at 25 °C on a rotary shaker under an atmosphere of 95% O₂ and 5% CO₂. Under these conditions there was no significant decline in cell viability and good preservation of cellular morphology on transmission electron microscopy for at least 24 h. Isolated hepatocytes in suspension at 25 °C were also able to maintain normal Na ⁺ and K ⁺ ion gradients. The cellular energy status ([ATP], ATP/ADP ratio, cytoplasmic and mitochondrial redox potentials), metabolic function (urea synthesis and ammonia removal), albumin synthesis and phase I and phase II drug detoxification activity of these cells were also maintained for at least 24 h post isolation. These observations demonstrate the robust nature of mildly hypothermic isolated hepatocytes in suspension and encourage further studies re‐examining the feasibility of using this cell preparation in bioartificial livers.     

Determination of peritoneal glucose kinetics in rats: implications for the peritoneal implantation of closed-loop insulin delivery systems

Summary Peritoneal glucose kinetics were evaluated in the anaesthetized rat, to assess whether the peritoneal cavity would be a suitable site for the implantation of membrane-protected islets of Langerhans (bioartificial pancreas) or the glucose sensor of an artificial B cell. Glucose was measured in peritoneal fluid samples aspirated by needle puncture. Basal peritoneal and blood glucose concentrations were identical in 16 h fasted (n=4) and non fasted (n=3) animals. After 10 min of an i.v. glucose infusion (n=15) the increment in peritoneal glucose concentration was 63±3% of the increment in blood glucose concentration and both values were significantly correlated (r=0.92; p<0.001). After 10 min of glucose clamping (12.6±0.8 mmol/l), the increment in peritoneal glucose concentration was 69±3% (n=5; p<0.05) of the increment in blood glucose concentration. In three additional experiments it was 93±3% of the increment in blood glucose concentration (NS), after 30 min of glucose clamping (8.0±0.5 mmol/l). Peritoneal glucose concentration monitored by a glucose sensor: (a) followed blood glucose sluggishly during a glucose clamp (n=5), confirming the data shown above, (b) followed blood glucose with a 5 min delay and reached the same plateau after the intravenous injection of 1U insulin (n=3; NS). We conclude that peritoneal glucose reflects blood glucose at basal state and during variations of glycaemia, nevertheless, presenting heterogeneous kinetics. These kinetics might be appropriate for a bioartificial pancreas but not for an in vivo calibration procedure, of a peritoneally implanted glucose sensor.     

Effects of bone marrow MSCs transfected with sRAGE on the intervention of HMGB1 induced immuno-inflammatory reaction

Background: High mobility group box chromosomal protein 1 (HMGB1) is an important proinflammatory molecule in many inflammatory disorders, but little is known about its role in acute liver failure (ALF). In this study, we determined the plasma and hepatic tissue levels of HMGB1 in a d-galactosamine-induced rat ALF model and investigated the effect of soluble receptor for advanced glycation end products (sRAGE) on ALF successfully. Methods: Male Sprague-Dawley rats were divided into five groups randomly. Group A (Control group, n=20) received administrated saline via peritoneal cavity. Group B (ALF group, n=20) induced by d-galactosamine (0.6 g/kg) via peritoneal cavity. Group C (HMGB1 group, n=20) were treated with HMGB1 recombination protein (200 μg/kg) via penile vein after ALF model induced. Group D (sRAGE group, n=20) received administrated sRAGE recombination protein (400 μg/kg) via penile vein after ALF model induced. Group E (sRAGE-MSC group, n=20) received 3×10⁶ MSC transplantation which could maintain a stable expression of sRAGE via penile vein after ALF model induced. Liver function, level of cytokines and liver pathological changes were measured. Results: We determined that the plasma levels and hepatic tissue levels of HMGB1 were significant increased in ALF model (P<0.05). SRAGE group and sRAGE-MSC group could significantly prolong ALF rat survival time, as well as improve its liver functions, inflammatory cytokines level and hepatocytes necrosis. Conclusion: SRAGE as a ligand decoy has illustrated largely beneficial effects on reducing immuno-inflammatory response, which holds promise for the identification of potential therapeutic targets and/or biomarkers of RAGE activity in ALF.     

Comparison of methods for isolating primary hepatocytes from mini pigs

Successful porcine hepatocyte isolation is crucial for the development of bioartificial liver devices and hepatocyte transplantation. Serva collagenase NB grades are formulated collagenases that are suitable for various tissue isolation applications. N‐acetylcysteine (NAC) can improve the viability of human hepatocytes. The aim of this study was to compare the effectiveness of two collagenases and effect of NAC on hepatocyte isolation from porcine liver tissue. Porcine hepatocytes were isolated using the perfusion method from Bama mini pigs assigned to the Serva NB 4 group (n=6), the Serva NB 8 group (n=6), or the NB 8+NAC group (n=6). Viability and yield were defined as fresh hepatocytes and their spheroids formation after 24‐hour rocker culture in serum‐free medium. Metabolic function was assessed by gene expression, albumin, and urea synthesis. All procedures resulted in successful hepatocyte isolation. Cells from the NB 8+NAC group had (97.8±1.9)% viability, which was higher than the NB 8 group with (94.4±2.4)% and the NB 4 group with (94.5±3.2)% (P<.001). The final cell yield reached (11.8±1.0)×10⁹ cells in the NB 8+NAC group, compared to (9.5±2.1)×10⁹ cells in the NB 8 group (P<.01) and (9.1±1.1) ×10⁹ cells in the NB 4 group (P<.001). The secretion of albumin was superior in the NB 8+NAC group at a concentration of (425.8±35.3) ng/mL compared to the NB 8 group (339.1±32.6) ng/mL (P <.001) and NB 4 group (293.6±43.3) ng/mL (P <.01). The injury of hepatocytes also decreased in the NB 8+NAC group (P<.01). The data are presented as means ± SD. Formulated collagenase Serva NB 8 and NAC could improve the porcine hepatocyte isolation, resulting in higher yields of viable cells.     

A comprehensive gene expression analysis of human hepatocellular carcinoma cell lines as components of a bioartificial liver using a radial flow bioreactor.

BACKGROUND/AIMS: The cells constituting a bioartificial liver are crucial for an effective liver support system. We compared global gene expression profiles in a radial flow bioreactor or a monolayer culture of three functional liver cell lines previously established from human hepatocellular carcinoma. METHODS: The expressions of 60,000 genes of the FLC-4, FLC-5, and FLC-7 cell lines were analyzed by the microarray technique with the Affymetrix GeneChip system. Global gene expression profiles were compared with two-way cluster analysis. Several liver function-related genes were compared between the bioreactor and culture conditions. RESULTS: Cluster analysis revealed that gene expression profiles of bioreactor-grown cells resembled those of the normal liver. Genes related to cellular structure were highly expressed in the bioreactor-grown cells, while genes involved in proliferation or carcinogenesis were suppressed. In the bioreactor-grown cells, some genes for liver functions were expressed at a level similar to that in normal liver, although none of the cell lines expressed the complete set of genes encoding ammonium metabolism or cytochrome P450 species. CONCLUSION: The high-density three-dimensional culture in the radial flow bioreactor prompted differentiation of the cells. These data may be useful for improving the cells by genetic or pharmacological reinforcement and for monitoring bioartificial livers.