Microfluidic Chip and Software for Microvascular Studies

描述（由申请人提供）：颗粒与组织（血管内皮）的粘附主要取决于颗粒/细胞特性（大小、受体）、血管的尺度/几何特征（直径、分叉等）和局部血流动力学因素（应力、扭矩等）。目前，这是使用体外平行板流室进行研究的，它存在几个严重的局限性，包括(a)理想的，大循环缩放(b)缺乏关键的形态学特征（连接，网络），健康与患病的脉管系统；(c)大容量（几毫升）和(d)由于不可一次性而造成的污染。我们建议开发一种新的基于微流体的细胞/药物颗粒粘附平台，以克服这些局限性。在第一阶段，从体内图像数据中获得解剖详细的微血管网络结构，并将其绘制在塑料一次性衬底（PDMS）上。灌注和颗粒粘附研究成功进行，并使用高保真计算模型分析数据。存在显著的停滞区，非直观的颗粒和流动分裂，空间上不均匀的粘附以及颗粒粘附依赖于血管分支角度的第一个证据被识别和记录。此外，在PDMS上培养内皮细胞，并通过上调粘附分子（p -选择素）和随后抗p -选择素包被颗粒对培养的内皮细胞的粘附证明了成功。试剂的净使用量减少了两个数量级以上。第一阶段的结果清楚地确立了利用所提出的微血管环境获得新的见解并对微血管中的颗粒粘附进行定量预测的价值。II期的工作将包括(a)扩展体内网络数据库（和理想化）(b)使用微/纳米颗粒和内皮细胞/癌细胞进行粘附研究，以及(c)通过计算模型验证生命内测量和分析。通过在真正模拟微血管环境的受控条件下研究颗粒/细胞组织相互作用，最终的II期产品将推进各种治疗领域的药物发现和递送研究，包括炎症、过敏/传染病、心血管疾病和癌症等。一个多学科团队在微循环和细胞粘附研究、微加工/微流体、计算建模和活体显微学方面具有专业知识。

DESCRIPTION (provided by applicant): Particle adhesion to tissue (vascular endothelium) depends critically upon particle/cell property (size, receptors), scale/geometric features of vasculature (diameter, bifurcation, etc.) and local hemodynamic factors (stress, torque etc). Currently, this is investigated using in-vitro parallel-plate flow chambers which suffer from several serious limitations including (a) idealized, macrocirculatory scaling (b) lack of critical morphological features (junctions, network), healthy vs. diseased vasculature and (c) large volumes (several ml) and (d) contamination due to non-disposability. We propose to develop a novel microfluidics-based platform for cell/drug-particle adhesion which overcomes these limitations In Phase I, anatomically detailed microvascular network structures were obtained from in-vivo image data and patterned onto a plastic, disposable substrate (PDMS). Perfusion and particle adhesion studies were successfully carried-out and the data was analyzed using high-fidelity computational models. The presence of significant stagnant regions, non-intuitive particle and flow splits, spatially non-uniform adhesion as well as first evidence of dependence of particle adhesion on vessel branching angle were identified and documented. In addition, endothelial cells were cultured on the PDMS and success was demonstrated with the upregulation of adhesion molecule (P-selectin) and subsequent adhesion of anti-P-selectin coated particle to the cultured endothelial cells. Net usage of reagents was decreased by over two orders of magnitude. Phase I results clearly established the value of using the proposed microvascular environment to gain new insights and make quantitative predictions on particle adhesion in the microvasculature. The Phase II efforts will include (a) expansion of the in-vivo network databases (and idealizations) (b) adhesion studies using micro/nano particles and endothelial/cancer cells and (c) validation against intra-vital measurements and analysis with computational models. By enabling the study of particle/cell-tissue interactions under controlled conditions that truly mimic the microvascular environment, the final Phase II product will advance drug discovery and delivery research in a variety of therapeutic areas including inflammation, allergy/infectious disease, cardiovascular disease and cancer among others. A multidisciplinary team has been assembled with expertise in microcirculation and cell adhesion research, microfabrication/microfluidics, computational modeling and intra-vital microscopy.