Investigation of the potential adverse effects of chemicals and drugs is essential during the drug development process. In vitro cell model systems have been developed over the past years towards such toxicity investigation. 96-well plate is the common platform for screening drug toxicity due to its simplicity. However, this platform only offers 2D cell culture environment and lacks the flow of solutions, which fails to provide the suitable environment for the cells to adequately metabolize the drugs, for the media to replenish, and for the metabolites and wastes to be removed. Microfluidic chips populated with human or animal cells, known as organ-on-a-chip (OOC), can reconcile many issues of in vitro cell models, such as the lack of extracellular matrix and flow as well as the species difference. However, OOC can be complicated to fabricate and operate. To bridge this gap, we utilized paper as a primary substrate for OOC, considering its fibrous structure that can mimic natural extracellular matrix, as well as a syringe pump and filter that are commonly available in most laboratories. Paper microfluidic model was designed and fabricated by wax printing on nitrocellulose paper, seeded and proliferated with liver cells (primary rat hepatocytes and HepG2 cells), and two paper substrates were stacked together to complete the paper model. To this paper-based liver cell model, the following drugs were added: Phenacetin (pain reliever and fever reducer), Bupropion (antidepressant), Dextromethorphan (antidepressant), and phosphate-buffered saline (PBS) as a control, all under a physiologically relevant flow rate. The combination of these drugs with Fluconazole (antifungal drug) was also investigated. Cell count, cell morphology, protein production, and urea secretion after drug treatment confirmed that the model successfully predicted toxicity within 40 minutes. This simple, paper-based liver cell model provided enhanced and faster cell response to drug toxicity and showed comparable or better behavior than the cells cultured in conventional 2D in vitro models.

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用于药物筛选的基于纸张的简单肝细胞模型

在药物开发过程中，对化学药品和药物的潜在不利影响进行调查至关重要。在过去的几年中，已经针对这种毒性研究开发了体外细胞模型系统。由于其简单性，96孔板是筛选药物毒性的常用平台。但是，该平台仅提供二维细胞培养环境，缺乏解决方案流程，无法为细胞充分代谢药物，补充培养基以及清除代谢产物和废物提供合适的环境。包含人或动物细胞的微流控芯片（称为“芯片上器官”（OOC））可以协调许多体外问题细胞模型，例如缺少细胞外基质和流动以及物种差异。但是，OOC的制造和操作可能很复杂。为了弥合这一差距，考虑到纸的纤维结构可以模仿天然的细胞外基质，以及大多数实验室普遍使用的注射泵和过滤器，我们将纸用作OOC的主要基材。通过在硝酸纤维素纸上打蜡设计，制造纸微流体模型，并在其上接种肝细胞（原代大鼠肝细胞和HepG2细胞）并进行增殖，然后将两个纸质基材堆叠在一起以完成纸模。在此基于纸张的肝细胞模型中，添加了以下药物：非那西丁（止痛药和退烧药），安非他酮（抗抑郁药），右美沙芬（抗抑郁药），和磷酸盐缓冲盐水（PBS）作为对照，均在生理相关的流速下进行。还研究了这些药物与氟康唑（抗真菌药）的组合。药物处理后的细胞计数，细胞形态，蛋白质产生和尿素分泌证实该模型成功预测了40分钟内的毒性。这个简单的，基于纸质的肝细胞模型提供了增强的和更快的细胞对药物毒性的反应，并显示了与常规2D培养的细胞相当或更好的行为体外模型。