Standard diagnostic tests for common bacterial infections such as strep throat are invasive and uncomfortable, especially for children. Difficulty performing these tests may delay or prevent diagnosis, which leads to more severe consequences, such as secondary conditions or organ damage. To address these barriers to care, we developed the CandyCollect, a novel saliva collection platform that is child-friendly, effective at pathogen collection, and suitable in at-home and clinical settings.The purpose of this study is to test the feasibility of our device’s bacteria capture for home use in healthy people. Staphylococcus aureus and Streptococcus mutans are common oral bacteria that are targeted in this study to assess our device’s ability to capture and detect bacteria. The findings in this study will inform our ability to use the CandyCollect for the bacterial pathogen responsible for strep throat, Streptococcus pyogenes, in future studies. We initally recruited 5 participants (>18 years) nationwide to test our CandyCollect device against oral swabs and spit tubes to compare the efficacy and user feedback of CandyCollect with traditional methods of saliva collection. The study is continuing with additional participants. qPCR analysis and fluorescent imaging were used to detect the target oral bacteria in collected samples. Responses from the user feedback survey indicated that the majority of the participants were satisfied with the design and were optimistic about implementing this device for children. Future applications include quantitative determination of bacteria concentration as well as targeting S. pyogenes. We aim to expand this human subjects study to recruit younger participants, especially children (> 3 years), which will help us achieve the ultimate goal of delivering a comfortable saliva collection platform to pediatric patients.

Microfluidics is the technology of systems in which microscale channels are used to manipulate small quantities of fluids (microliter to picoliter or less). Open microfluidics provides a platform to control the movement of microscale volumes of liquid in open space, making every position more accessible than conventional closed microfluidics. In many applications–including cell culture, chemical synthesis, and high throughput screening–merging droplets is essential for the experimental workflow. For example, merging droplets containing reagents can initiate a chemical reaction, or adding a drug to a cell culture can stimulate cells. In conventional closed droplet-based microfluidics, merging techniques often rely on external components such as merging by electrofusion using electrodes. In other cases, like merging using hydrophilic strips in a channel, the merging method is built into the device and the location of merging must be determined in advance. Therefore, the ability to easily initiate droplet merging in an open microfluidic system would be beneficial to researchers and offer flexibility in experimental design and applications. In this study, I developed an easily accessible droplet fusion technique with the prick of a needle at the liquid interface; my method fuses multiple droplets simultaneously (2-15 droplets). Importantly, this fusion method can be used on-demand at any point in the open microfluidic device and does not require external equipment nor features built into the device. This presentation characterizes the experimental parameters required for successful and controlled droplet fusion and explores the physics behind this phenomenon.

Chronic inflammation in the lung often leads to airway remodeling, which can worsen symptoms in inflammatory diseases such as asthma. Airway remodeling is attributed to the excessive deposition of the extracellular matrix (ECM) by myofibroblasts, which are a differentiated form of fibroblasts. Eosinophils, when activated by interleukin-3 (IL-3), release certain soluble factors that were found to be associated with inflammation in asthmatic tissues. Hence, it is crucial to study cellular communication in airway remodeling to facilitate the development of treatments. The aim of this project is to establish an in vitro model of asthma by coculturing primary human lung fibroblasts and eosinophils to study the soluble factors that trigger airway remodeling. We hypothesize that IL-3 activated eosinophils, when immunoglobulin (IgG) is added, release soluble factors that trigger the gene expression and phenotypic changes in fibroblasts. The coculture device has two chambers, in which two types of cells can be cocultured in the shared media while being physically separated by a half wall. Eosinophils are seeded in the outer chamber of the devices and degranulated. The differentiation of fibroblasts would then be quantified by utilizing immunocytochemistry to see the differences in expression levels of alpha smooth muscle actin (É‘SMA) in fibroblasts, in addition to quantitative polymerase chain reaction (qPCR) to detect messenger RNA (mRNA) level associated with inflammation and tissue remodeling. The initial experiments were focused on the monoculture of fibroblasts to ensure that reliable readouts can be obtained from fibroblasts before initiating the coculture. The preliminary data suggest that the fibroblasts treated with transforming growth factor beta 1 (TGF-β1), which promote differentiation, result in significantly higher expression of É‘SMA. Our future experiments include initiating the coculture of eosinophils and fibroblasts to fully illustrate this crucial cellular communication in airway remodeling.

The rapid rise of bioanalytical testing has renewed discussions in improving the collection of bacteria through oral sampling. Current diagnostic tests for common respiratory illnesses such as strep throat are invasive and uncomfortable, especially for children. Undiagnosed, these treatable diseases can cause serious damage. The Theberge lab has created the CandyCollect, a saliva sampling device intended to be a child-friendly alternative to current sampling techniques for home and clinical settings. The CandyCollect utilizes candy in the design to appeal to children, a unique component that requires additional testing and standardization to be appropriately implemented. This study explores the intersectionality of safety, design, effectiveness, and ease of application by using candy to increase children's compliance and act as a built-in timer. Our goal is to modify the existing device with these objectives in mind. Several types of candy were made using different ingredients, flavors, and textures, and the interaction of these candies with oral bacteria and saliva was investigated. We engineered the device using rapid prototyping, computer-numerical-control (CNC) milling, and silicone mold development. These methods allow for the flexibility to modify the design of the candy and sampling device. We then designed a survey for a human subjects study for adults (>18 years) to receive useability feedback and adapt the device components. Our analysis of these results determines the variety of candy that is most suitable for large scale use. The findings of this study will offer an improved method for child diagnostics and encourage other industries to redesign traditional sampling procedures.