Project abstract for group haynescl

The Investigation of Blood Vessel Functions Using Microfluidic Platform

These researchers are involved in two projects using MSI:

  • Investigation of Drug Effects on Neutrophil Chemotaxis and Viability in Inflammatory Disease: Chronic obstructive pulmonary disease (COPD) and asthma are diseases characterized by neutrophilic airway inflammation, where neutrophils perform excessive chemotaxis and impaired apoptosis to accumulate around infection sites. Development of anti-inflammatory approaches to reduce neutrophil chemotaxis and induce neutrophil apoptosis are essential for the treatment of these global diseases. To gain fundamental insight toward therapeutic treatment, this work investigates the effects of three potential anti-inflammatory drugs on neutrophil migration and viability using a microfluidic platform. Microfluidics is a potent technology based on precise manipulation of fluid flow at the microscale level. Compared to traditional methods, microfluidic platforms are able to establish chemical gradients with controlled and high spatiotemporal resolution. Also, cell imaging through the transparent devices facilitates collection of quantitative data to describe cellular chemotactic behaviors and differentiate responses in various conditions. A CXCR2 antagonist, a blocking agent of the receptor that initiates neutrophil chemotaxis, demonstrated inhibition of chemotaxis and increased cytotoxicity at high concentrations and long incubation times. Another potential drug candidate, an inhibitor of the PI3K enzyme located upstream in the neutrophil chemotaxis signaling pathway, demonstrated mild impacts on cell viability and a concentration-independent decrease in neutrophil chemotaxis. Theophylline, a widely used drug for respiratory diseases, did not influence neutrophil polarization in chemotaxis; however, the introduction of theophylline resulted in the largest drop of cell viability among these three drugs. This work provides new insights on the mechanisms of cell-drug interaction and guides treatment application for neutrophilic inflammation.
  • Characterization of Neutrophil Transendothelial Migration in Vascular Similar Microenvironment Based on Microfluidic Platform: Neutrophil transendothelial migration (TEM) plays an important role in inflammatory response. A variety of cytokines and proteins are involved in this complicated cascade to regulate the tightly ordered interactions between neutrophils and endothelial cells. This investigation of the neutrophil TEM process, again facilitated via microfluidic platforms, is likely to provide deep insights into the molecular mechanisms of cell-cell interactions and the pathogenesis of neutrophil-related diseases. Traditional assays are not capable of characterizing the TEM process due to low spatial and temporal resolution, as well as the inability to simulate the 3D microenvironment. Within the microfluidic device to be used in this work, stable chemoattractant gradients and a 3D endothelial cell layer will be incorporated to create an in vivo-like microenvironment for neutrophil TEM observation. The incubated collagen gel will enable the formation of an endothelial cell layer on the side wall to mimic vascular structure, and a porous gel composition will allow the diffusion of chemoattractant molecules to initiate neutrophil TEM. The number of neutrophils transmigrating through endothelial cell layer into the collagen gel and the migration distance will be determined using in situ imaging of fluorescently labeled cells. Furthermore, competing chemoattractant gradients will be developed to explore neutrophil TEM in complex physiological environments. A versatile microfluidic platform with the ability of reconstituting microvascular structure will be developed to visualize neutrophil TEM process in this work.

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