Cellular Composite Device for Combination Therapy of Acute Liver Failure

描述（由申请人提供）：肝衰竭是第七大死因，在美国每年造成50,000人死亡。原位肝移植是唯一被证实有效的治疗急性肝衰竭（ALF）的方法，但由于器官供体短缺、相关的高成本和终身免疫抑制的要求，其应用受到限制。目前和预计的肝衰竭患者数量都在不断增长，需要一种替代移植的救命方法来支持患者。生物人工肝装置是支持ALF患者进行移植的合理途径。五种基于细胞的设备已经在人类和猪身上进行了测试，似乎是安全的，但没有一种显示出生存效益。迄今为止设备的失效表明作用机制无效。终末期肝功能衰竭导致与炎症反应同时发生的全身性功能障碍。我们假设，提供肝细胞支持以及细胞保护、抗炎和营养支持的联合治疗方法将涵盖广泛的病理过程，可以稳定患者。在原理验证治疗试验中，我们已经证明人间充质干细胞（MSCs）自然分泌具有免疫调节特性的生物活性分子。我们已经开发出基于骨髓间质干细胞的设备，这种设备可以在体外运行，并连接到受试者的循环系统以提供长期支持，并且已经表明，当连接其中一个设备10小时时，接受ALF的大鼠的存活率从不足15%增加到70%以上，增加了5倍。这个I期项目的总体目标是开发一种用于治疗ALF的复合细胞生物反应器，将肝细胞和间充质干细胞的代谢和分泌整合在一个单元中，并评估这种双细胞设备在MSC设备有效性之上的附加效益。项目具体目标为：(1)优化MSCs与肝细胞体外共培养，模拟肝功能衰竭血清对共培养功能的影响；(2)将间充质干细胞和肝细胞整合到平板设备中，并在啮齿动物模型中启动生物反应器治疗的治疗试验。在这个项目成功完成后，交付的产品将是一个原型细胞装载透析盒，可以很容易地扩大规模，并在大型动物身上进行测试。

DESCRIPTION (provided by applicant): Liver failure is the 7th leading cause of death and is responsible for 50,000 deaths per year in the United States. Orthotopic liver transplantation is the only proven effective treatment of acute liver failure (ALF), but its use is limited due to organ donor shortage, associated high costs, and the requirement of lifelong immunosuppression. The present and expected growth of the population that is affected by liver failure is ever rising and a life-saving alternative to transplantation is needed to support patients. Bioartificial liver devices are a rational approach to support ALF patients as a bridge to transplantation. Five cell- based devices have been tested in humans and pigs and appear safe, but none have shown a survival benefit. The failure of devices to-date suggests an ineffective mechanism of action. End-stage liver failure leads to systemic dysfunction that is occurring simultaneously with an inflammatory response. We hypothesize that a combination approach to therapy that provides hepatocellular support along with cytoprotection, anti-inflammatory, and trophic support will cover the broad spectrum of pathological processes that can stabilize a patient. In proof-of-principle therapeutic trials, we have demonstrated that human mesenchymal stem cell (MSCs) naturally secrete bioactive molecules that have immunomodulatory properties. We have developed MSC-based devices that are operated outside the body and connect to a subject's circulation to provide long-term support, and have shown that when connected to one of these devices for 10 hours, rats undergoing ALF have a 5-fold increase in survival from less than 15% to over 70%. The overall goal of this Phase I project is to develop a composite cellular bioreactor for the treatment of ALF that integrates both hepatocyte and MSC metabolism and secretion in a single unit, and evaluate the added benefit of this two-cell device over and above the effectiveness of the MSC devices. The project specific aims are: (1) To optimize the in vitro coculture of MSCs and hepatocytes and simulate the effect of liver failure serum on the function of the coculture; and (2) To incorporate MSCs and hepatocytes into flat-plate devices and initiate therapeutic testing of bioreactor treatments in rodent models. Upon successful completion of this project, the deliverable will be a prototype cell-laden dialysis cartridge that can be readily scaled up and tested in large animals. PUBLIC HEALTH RELEVANCE: We propose to develop an extracorporeal bioartificial liver device that offers unparalleled support to patients undergoing liver failure. The device will contain hepatocytes and mesenchymal stem cells (MSCs). The addition of MSCs is unique to our technology and is designed to enhance the metabolic functions of hepatocytes exposed to plasma and restore the regulation of the dysfunctional immune system in patients undergoing liver failure by active MSC secretion anti-inflammatory and trophic molecules. This two-pronged approach distinguishes this device from current prototypes. Our objectives are to perform in vitro optimization of the coculture using metabolic engineering of the coculture and in vivo testing of a microfabricated coculture device in two rat models of liver failure. These studies will determine if the combination therapeutic approach can be indicated for a broad range of liver disease etiologies and will motivate testing in large animal models of liver failure, and ultimately in human patients.