An iPSC based xeno-free platform to assess the foreign body response against new biomaterials

基于 iPSC 的无异源平台，用于评估新生物材料的异物反应

• 批准号: NC/Y000838/1
• 负责人: Amir Ghaemmaghami
• 金额: $ 76.31万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NC%2FY000838%2F1
• 关键词: iPSC; based; xeno; free; platform

Implantable biomaterials and medical devices have become mainstream solutions for a variety of health problems and their use is constantly increasing. However, the materials used in these devices can be seen as foreign by the immune system triggering adverse immune reactions that could harm the patient and stop the device from working. These responses (generally known as foreign body response or FBR) are initiated by immune cells circulating in the blood (e.g. T cells and monocytes) and those that are resident (e.g. macrophages) in the tissues where the devices are implanted. Macrophages attack implants in an attempt to clear them from the body which leads to complications including inflammation and formation of dense tissues (fibrotic capsules) that surround the devices. Such complications are major causes of corrective surgeries costing the health system billions annually and causing significant suffering for millions of patients. There is therefore significant interest in investigating FBR for new biomaterials, unfortunately however, there is a heavy reliance on animal models in the biomaterials discovery pipeline with thousands of animals used in both academia and industry each year. In addition to ethical issues, these models are expensive, and have poor physiological relevance to human not least due to fundamental differences between the immune system in humans and the animals. Thus, there is an unmet need for developing better in vitro models to investigate FBR.To address this need we will build a stem cell based, microfluidic device that can model the FBR and be used to test new biomaterials for compatibility with implantation. We will achieve this via 4 interlinked tasks:Task 1: Development of Xeno-free hIPSC differentiation of immune and stromal cells. We have developed and validated an efficient, xeno-free stem cell differentiation platform to create all of the necessary cell types required for our model (endothelium, fibroblasts, macrophages and T-cells) in a single media and will finalise development of T-cells in our xeno-free system. Task 2: Optimising static co-cultures of different cell types and cell supply. Our differentiation platform is based on a single cell culture media for all cell types making coculture of the different cell types more simplified. We will mix different cell types together at ratios that reflect healthy human tissue and assess baseline levels of cell metabolism, proliferation, death and inflammatory profiles. Task 3: Microfluidic platform assembly and optimisation. We will build the microfluidic device containing compartments replicating vascular networks, stromal tissue and pumps simulating blood flow. We will further optimise long term cellular function of the device to achieve a functional life span of at least 2 weeks. Task 4: Validation of in the new platform using a selection of well characterised biomaterials. We will compare the performance of the new platform by investigating FBR to a selection of clinically relevant biomaterials where we have access to existing in vivo data from well established animal models. This will enable us to fine tune different aspects of the new device (cell numbers, rations, flow rates) to optimise the device performance if necessary. Together these objectives will deliver a stem cell based, microfluidic FBR model that will recapitulate the three-dimensionality of the target tissue and the dynamic events occurring in immune responses to implanted devices, including recruitment of circulating immune cells to the site of the implant, immune cell migration through blood vessels and connective tissues and their interactions with other cells in the local area. The model will not be reliant on primary cell types/donors and therefore reduce variability of the platform. Ultimately, this will allow more accurate biomaterial discovery while replacing the need to use tens of thousands of animals per year in biomaterial testing.

植入式生物材料和医疗器械已成为多种健康问题的主流解决方案，且其使用量不断增加。然而，这些设备中使用的材料可能会被免疫系统视为异物，从而引发不良免疫反应，从而伤害患者并阻止设备工作。这些反应（通常称为异物反应或 FBR）是由血液中循环的免疫细胞（例如 T 细胞和单核细胞）以及植入设备的组织中驻留的免疫细胞（例如巨噬细胞）发起的。巨噬细胞攻击植入物，试图将其从体内清除，这会导致并发症，包括炎症和装置周围致密组织（纤维化胶囊）的形成。这些并发症是矫正手术的主要原因，每年给卫生系统造成数十亿美元的损失，并给数百万患者带来巨大痛苦。因此，人们对研究新生物材料的 FBR 非常感兴趣，但不幸的是，在生物材料发现管道中严重依赖动物模型，每年学术界和工业界都使用数千只动物。除了伦理问题外，这些模型价格昂贵，并且与人类的生理相关性较差，尤其是由于人类和动物的免疫系统之间存在根本差异。因此，开发更好的体外模型来研究 FBR 的需求尚未得到满足。为了满足这一需求，我们将构建一种基于干细胞的微流体装置，可以模拟 FBR 并用于测试新生物材料与植入的兼容性。我们将通过 4 个相互关联的任务来实现这一目标： 任务 1：开发免疫细胞和基质细胞的无异种 hIPSC 分化。我们开发并验证了一个高效、无异源的干细胞分化平台，可在单一培养基中创建我们的模型所需的所有必需细胞类型（内皮细胞、成纤维细胞、巨噬细胞和 T 细胞），并将最终完成 T 细胞的开发在我们的无异源系统中。任务 2：优化不同细胞类型和细胞供应的静态共培养。我们的分化平台基于适用于所有细胞类型的单细胞培养基，使不同细胞类型的共培养更加简化。我们将以反映健康人体组织的比例将不同的细胞类型混合在一起，并评估细胞代谢、增殖、死亡和炎症特征的基线水平。任务 3：微流控平台组装和优化。我们将构建包含复制血管网络、基质组织和模拟血流的泵的微流体装置。我们将进一步优化设备的长期细胞功能，以实现至少 2 周的功能寿命。任务 4：使用精选的特征良好的生物材料在新平台中进行验证。我们将通过研究 FBR 与精选的临床相关生物材料来比较新平台的性能，在这些生物材料中我们可以从成熟的动物模型中获取现有的体内数据。这将使我们能够微调新设备的不同方面（细胞数量、定量、流速），以在必要时优化设备性能。这些目标共同将提供一个基于干细胞的微流体 FBR 模型，该模型将概括目标组织的三维性以及对植入设备的免疫反应中发生的动态事件，包括将循环免疫细胞募集到植入物部位、免疫细胞通过血管和结缔组织的迁移及其与局部区域其他细胞的相互作用。该模型将不依赖于原代细胞类型/供体，因此减少了平台的可变性。最终，这将允许更准确的生物材料发现，同时取代每年在生物材料测试中使用数万只动物的需要。