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（尺寸、受体）、血管系统的规模/几何特征（直径、分叉等）和局部血液动力学因素（应力、扭矩等）。目前，这是使用体外平行板流动室进行研究的，所述流动室遭受几个严重的限制，包括（a）理想化的大循环缩放（B）缺乏关键形态特征（连接、网络）、健康与患病的脉管系统和（c）大体积（几ml）和（d）由于不可处置性而造成的污染。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，克服了这些限制。在第一阶段，从体内图像数据中获得解剖学上详细的微血管网络结构，并将其图案化到塑料一次性基底（PDMS）上。成功地进行了灌注和颗粒粘附研究，并使用高保真计算模型分析了数据。确定并记录了显著停滞区域、非直观颗粒和流动分裂、空间非均匀粘附以及颗粒粘附依赖于血管分支角的第一个证据。此外，在PDMS上培养内皮细胞，并且成功地证明了粘附分子（P-选择素）的上调和随后的抗P-选择素涂覆的颗粒与培养的内皮细胞的粘附。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建立了使用所提出的微血管环境的价值，以获得新的见解，并对微血管中的颗粒粘附进行定量预测。II期工作将包括（a）体内网络数据库（和理想化）的扩展（B）使用微/纳米颗粒和内皮/癌细胞的粘附研究和（c）使用计算模型对活体内测量和分析进行验证。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。一个多学科的团队已经组装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镜的专业知识。

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.