Advances in diagnostic technology and microscale analysis are transforming the field of biomedical research, enabling more precise and efficient detection and analysis of diseases and biological processes. This work explores innovative approaches in point-of-care diagnostics, microfluidic platforms, and high-throughput screening methods to address challenges in disease diagnosis and cellular analysis.In Chapter 1, we present a point-of-care (POC) serological test for Lyme disease (LD), using synthetic peptides specific to LD antibodies on a paper-based platform for rapid and cost-effective diagnosis. By targeting antigenic epitopes conserved across Borrelia burgdorferi genospecies, we develop a multiplexed panel to detect LD-specific IgG and IgM antibodies from patient sera. The combination of multiple peptide epitopes and a machine learning-based diagnostic model achieves high sensitivity without sacrificing specificity. Blinded validation with samples demonstrates 95.5% sensitivity and 100% specificity, accurately matching lab-based two-tier testing and differentiating LD from similar diseases. This diagnostic test has the potential to replace the cumbersome two-tier testing, improving early diagnosis and treatment while enabling better immune monitoring and surveillance.
In Chapter 2, we discuss how Lab on a Particle (LoP) platforms leverage microparticles for microscale reactions and molecular and cellular analysis. We describe the evolution of hydrogels for single-cell encapsulation and the emergence of hollow core-shell microparticles that are highly parallelizable and analyzable with standard lab instruments like flow cytometers and microscopes. These particles can be used to design custom screening workflows for cell and molecular screening pipelines, enabling high-throughput, massively parallelized analysis and advanced assay capabilities.
In Chapter 3, we present a high-throughput function-first screening platform using core-shell microparticles to compartmentalize individual variants into suspendable colonies for large-scale analysis. By integrating this approach with flow cytometry and deep mutational sequencing, we screen extensive libraries of GCaMPs, genetically encoded calcium indicators, achieving unprecedented throughput by assessing millions of variants within hours. This method allows for the selection based on multi-functional criteria and identified GCaMP variants with over a 10-fold improvement in dynamic response. This innovative platform holds potential to revolutionize fluorescent biosensor engineering and can be broadly applied to screen cells and other proteins, facilitating the discovery of rare, high-performing variants and measuring complex functions that are challenging with traditional methods.
Overall, this thesis presents significant advancements in point-of-care diagnostics, microfluidic platforms, and high-throughput screening technologies that address current limitations in disease detection and protein engineering. By introducing novel diagnostic tools for Lyme disease, expanding the capabilities of Lab on a Particle platforms, and developing innovative approaches for screening biosensors, this work lays the foundation for more efficient, scalable, and precise biomedical applications. The technologies developed have the potential to not only improve clinical diagnostics but also accelerate research in discovery, cellular analysis, and synthetic biology. The commercialization and widespread adoption of these tools could bridge critical gaps in healthcare and biotechnology, ultimately improving patient outcomes and driving progress in biomedical research.
