Quantitative microfluidic delivery systems for studying tissue microenvironment and microvascular blood flow regulation in vivo

用于研究体内组织微环境和微血管血流调节的定量微流体输送系统

• 批准号: RGPIN-2017-05205
• 负责人: Fraser, Graham
• 金额: $ 1.68万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=711248
• 关键词: Quantitative; microfluidic; delivery; systems; studying

BACKGROUND: The nutritive requirements of all body tissues are provided for by the dynamic distribution of blood flow to microvascular networks throughout the body. Studying blood flow regulation in vivo requires specialized, minimally invasive, surgical preparations in order to isolate a tissue of interest while preserving the normal function and control of the regulatory system itself. We have previously developed gas exchange chambers to manipulate gas partial pressures in skeletal muscle of live rats. This work demonstrated the feasibility and efficacy of these devices and that the microcirculation can respond to changes in the surrounding microenvironment. We propose the development of novel microfluidic devices that allow for the introduction of dyes and pharmacological agents to skeletal muscle for the purposes of studying blood flow regulation and mass transport. OBJECTIVES: 1) Develop a microfluidic device and fluid flow system capable of maintaining a fixed solute concentration, temperature, and physiologic gas conditions, at the surface of an intact tissue in vivo while simultaneously allowing visualization and quantification of blood flow within the tissue. 2) Validate the efficacy of the device to deliver compounds into the overlying tissue using dyes, fluorescent probes, and vasoactive drugs. 3) Create mathematical mass transport models of the microfluidic device and overlying tissue to calculate the tissue concentration and gradients of solutes within the tissue given known conditions within the microfluidic flow chamber, physical properties of the tissue, and blood flow in the microcirculation. 4) Apply the microfluidic system and mathematical model to interrogate microvascular regulatory mechanisms in intact skeletal muscle using various vasoactive agonist, antagonists, and drugs. SCIENTIFIC APPROACH: Microfluidic devices will be constructed using precision laser cut glass and molded plastics made with soft lithography techniques. Flow within the device will be controlled using standard micro-flow valves connected to a computer system. Visualization and measurement of microvascular blood flow will be achieved using high-powered microscopy of rat skeletal muscle. Computer models will be used to inform the experimental results and calculate the depth to which substances delivered via the microfluidic channel will penetrate into the tissue. IMPACT: The projects related to this program will provide excellent training opportunities for young scientists and students interested in the fundamental function of our cardiovascular systems. This research will produce a novel technology for studying microvascular function in vivo as well as a platform for interrogating the microenvironment of living tissue. These innovations will influence many areas in biomedical research, particularly those related to understanding integrated microcirculation.

背景：人体所有组织的营养需求是由血液流向全身微血管网络的动态分布提供的。研究体内血流调节需要专门的、微创的外科准备，以便在保留调节系统本身的正常功能和控制的同时分离感兴趣的组织。我们之前已经开发了气体交换室来控制活体大鼠骨骼肌中的气体分压。这项工作证明了这些装置的可行性和有效性，以及微循环可以对周围微环境的变化做出反应。 我们建议开发新型微流控装置，允许将染料和药物引入骨骼肌，以研究血流调节和质量传输。 目的：1)开发一种微流控装置和流体流动系统，能够在活体完整的组织表面保持固定的溶质浓度、温度和生理气体条件，同时允许可视化和量化组织内的血流。2)验证使用染料、荧光探针和血管活性药物将化合物输送到覆盖组织中的装置的有效性。3)创建微流控装置和覆盖组织的质量传输数学模型，以计算给定微流控流室内已知条件、组织的物理性质和微循环中的血液流动时组织内的组织浓度和溶质的梯度。4)应用微流控系统和数学模型，研究各种血管活性激动剂、拮抗剂和药物对完整骨骼肌微血管调节机制的影响。 科学方法：微流控设备将使用精密激光切割玻璃和用软光刻技术制造的模塑塑料来构建。该装置内的流量将使用连接到计算机系统的标准微流量阀进行控制。微血管血流的可视化和测量将使用大鼠骨骼肌的高倍显微镜来实现。计算机模型将被用来通知实验结果，并计算通过微流体通道输送的物质将渗透到组织中的深度。 影响：与该项目相关的项目将为对心血管系统基本功能感兴趣的年轻科学家和学生提供极好的培训机会。这项研究将产生一种研究体内微血管功能的新技术，以及一个询问活组织微环境的平台。这些创新将影响生物医学研究的许多领域，特别是与理解整合微循环相关的领域。