An Affordable New Approach to Diagnosis and Analysis of Cells and Molecules
Researchers at Texas A&M University (TAMU) have engineered a novel portable and robust microscale system enabling advanced diagnostics and analysis of cells and molecules without the sophisticated instruments previously required, opening up new opportunities for helping people at the point-of-care in the developed and developing world. This work is being supported by the NSF-funded Precise Advanced Technologies and Health Systems for Underserved Populations (PATHS-UP) Engineering Research Center (ERC), headquartered at TAMU, with partners from the University of California at Los Angeles, Rice University, and Florida International University.
The vision of the PATHS-UP ERC is to change the paradigm for the health of underserved populations worldwide by developing revolutionary and cost-effective technologies and systems accessible where they live. This project was aimed at improving the ability to create uniform chemical compounds in sufficient quantity to enable affordable new approaches for analyzing single cells and molecules and accelerating the adoption of cutting-edge applications. This work is early-stage but highly promising. Nonlinear fluid dynamic effects are usually not considered in microfluidic systems, but might provide simple methods to manipulate and sort rare populations of cells at high throughputs. In contrast to traditional emulsions, particle-templated drops of a controlled volume occupy a minimum in the interfacial energy of the system, such that a stable monodisperse state results, with simple and reproducible formation conditions.
Simple mixing of aqueous and oil solutions with amphiphilic particles leads to the spontaneous formation of uniform reaction volumes (“dropicles”) that can enable many kinds of applications in the analysis of biological entities such as cells and molecules. Approaches to the manufacture of such amphiphilic particles are just starting to be investigated. The researchers investigated the tunable manufacturing of concentric amphiphilic particles, with outer hydrophobic and inner hydrophilic layers, fabricated by flowing reactive precursor streams through a 3D-printed device with coaxial microfluidic channels, and curing the structured flow by UV exposure through a photomask. The dimensions of the engineered amphiphilic particles—including height, inner and outer diameters, and thicknesses of the hydrophobic and hydrophilic layers—are precisely controlled by modulating the UV exposure time, the precursor flow rate ratios, and the size of the channel in the exposure region. The particle design is systematically engineered to hold a wide range of droplet volumes—that is, from a few hundred picoliters to several nanoliters. The particle size can be significantly reduced from previous capabilities to not only hold sub-nanoliter droplets, but also to tune the shape to increase the seeding density and orientation of dropicles within a well plate for imaging and analysis.
