High Density 3D Printed Microfluidics for Cell-Based Biomedical Applications

项目摘要 生长因子、其他细胞信号分子和营养物质的浓度梯度推动着 一系列关键的生物学过程，包括免疫细胞迁移、血管生成、伤口愈合、 癌症转移和生物体发育。微流控装置被广泛用于创建 相关的浓度梯度，并监测细胞对该梯度的响应行为。 不幸的是，大多数浓度梯度微流控装置的设计完全假设 扩散输送过程，同时纳入平流输送解耦战略，这些战略是 很大程度上无效和/或缓慢。这种方法会导致特定和重要的缺点，包括低 梯度中的动态范围，测量生命周期内的不稳定梯度，以及 设备的不同空间区域之间的梯度不一致。因此，现有的 构建浓度梯度的微流体方法不能充分模拟扩散- 产生了体内发现的浓度梯度。因此，对微流体有大量未得到满足的需求 能够快速创建稳定且灵活的浓度梯度的设备，允许敏感 监控关键的细胞过程。 此续订计划侧重于利用和扩展复杂的高分辨率3D 用于微流体的打印技术，以创建产生浓度梯度的集成设备 具有可在多个信源和信宿解决方案之间切换的大动态范围 可选择的浓度和快速设置时间(几分钟)，以实现临时多路传输 稳定的浓度梯度序列。研究工作将由三个具体目标组成。第一, 将使用3D模拟来评估大范围的浓度梯度形成 基于源流体和汇流体的新的反向流动概念的几何，目标是 将平流与扩散质量输送脱钩，前者需要前者来补充来源 和下沉流体，而后者需要产生浓度梯度。接下来，各种 将对候选几何图形进行3D打印和测试，以迭代优化浓度梯度 动态范围、设置时间、稳定性和一致性。最好的候选人将与芯片集成 泵、阀门、串联稀释器和储液器，以创建集成系统。最后，这样的设备将被 用于分析代谢工程细菌的趋化性。开发的新功能已超过 授权期的设计是为了能够回答关于以下方面的重要问题 发育生物学、细胞对营养提示的反应，以及血管生成和癌症生长 和侵犯性。

Project Summary Concentration gradients of growth factors, other cell-signaling molecules, and nutrients drive a wide range of critical biological processes, including immune cell migration, angiogenesis, wound healing, cancer metastasis, and organism development. Microfluidic devices are extensively used to both create the relevant concentration gradient, and to monitor cellular behavior in response to that gradient. Unfortunately, most concentration gradient microfluidic devices are designed assuming exclusively diffusional transport processes, while incorporating advective transport decoupling strategies that are largely ineffective and/or slow. This approach results in specific and important drawbacks, including low dynamic range in the gradient, unstable gradients over the lifetime of the measurement, and inconsistency in the gradient between different spatial regions of the device. As a result, existing microfluidic approaches to concentration gradient construction do not adequately mimic the diffusion- generated concentration gradients found in-vivo. Hence, there is a large unmet need for microfluidic devices that can rapidly create stable and flexible concentration gradients that allow sensitive monitoring of critical cellular processes. This renewal proposal focuses on leveraging and extending sophisticated high resolution 3D printing technology for microfluidics to create integrated devices that generate concentration gradients with large dynamic range that are switchable between multiple source and sink solutions with selectable concentration and rapid set up time (few minutes) to enable temporal multiplexing of sequences of stable concentration gradients. Research efforts will consist of three specific aims. First, 3D simulation will be employed to evaluate a wide range of concentration gradient formation geometries based on a new opposing-flow concept for source and sink fluids with the objective of decoupling advective from diffusive mass transport, where the former is needed to replenish source and sink fluids while the latter is required to generate the concentration gradient. Next, a variety of candidate geometries will be 3D printed and tested to iteratively optimize concentration gradient dynamic range, set up time, stability, and uniformity. The best candidates will be integrated with on-chip pumps, valves, serial diluters, and reservoirs to create integrated systems. Finally, such devices will be used to analyze chemotaxis of metabolically engineered bacteria. The new capabilities developed over the grant period are designed to allow important questions to be answered with respect to developmental biology, cellular response to nutritive cues, as well as angiogenesis, and cancer growth and invasiveness.