Engineering Fluidic Tools for Translational Science: Developing In Vitro Tissues and Remote Sampling Platforms

Abstract

This dissertation discusses the development and optimization of various open microfluidic inspired toolsfor translational science applications in studying human health and the environment. Chapter 1 introduces the field of open microfluidics and provides background into open microfluidic hydrogel patterning for tissue engineering and at-home blood sampling for downstream transcriptomic analysis. Chapter 2 describes a novel removable suspended open microfluidic platform for patterning hydrogel-based tissue constructs suspended between two posts. This platform uses microfluidic principles such as surface tension and capillary pinning to control the flow and shape of hydrogels in a suspended format to generate engineered tissue constructs with defined interfacial regions for disease and tissue junction modeling. Chapter 3 explores the use of homeRNA, a previously established kit for at-home user-based blood collection and stabilization, in high temperature settings via two pilot studies conducted in the hot summer months in the Western and South Central United States and Doha, Qatar. These pilot studies yielded RNA from homeRNA-stabilized samples of sufficient quality for use in downstream transcriptomic analysis despite exposure to temperatures greater than 37°C. Chapter 4 further establishes the robustness of homeRNA by systematically testing RNA quality from homeRNA-stabilized samples after short-term (<2 days) and long-term exposure (>2 days) to a range of temperatures above 37°C via in-lab testing and a realworld controlled shipping experiment. These samples were then sequenced using 3’ mRNA-sequencing technology, which showed little to no preferential transcript degradation of isolated RNA from homeRNAstabilized samples due to high temperatures or extended shipping times. Chapter 5 then outlines the first use of homeRNA with bulk RNA-sequencing, in which we demonstrated that homeRNA can successfully capture an LPS-induced inflammatory response that was comparable to that of stabilized venous blood. This work establishes the compatibility of homeRNA with bulk RNA-sequencing, demonstrating its potential as a useful tool for monitoring immune response via remote sampling. Lastly, Chapter 6 describes a yearlong homeRNA-based remote study to probe immune response to wildfire smoke exposure in the Western and South Central United States. This demonstrates the ability of homeRNA to be used in a fully remote and flexible study design for user-based blood collection in challenging environments. Ongoing work with this study includes investigating the gene expression profile of homeRNA-stabilized samples from 32 unique participants to elucidate the transcriptomic immune response to wildfire smoke. This dissertation presents two bioanalytical platforms that advance translational medicine by enabling more targeted biological and health-related investigations. Combined, STOMP and homeRNA collectively expand the scope of translational research in tissue engineering and remote sampling applications, thus supporting more targeted investigations into disease mechanisms, therapeutic efficacy, and environmental health impacts.