Integration of Biomimetic Microparticle-based Multiplexed Assays and Microfluidic Systems for High Throughput Quantitative Detection and Discrimination of Endocrine Disrupting Chemicals

Endocrine disrupting chemicals (EDCs) can disturb development of the endocrine system and organisms directly or indirectly exposed during prenatal and early postnatal life. The current methods for the determination of EDCs involve time-consuming detection processes and complex pre-treatment steps, which are not suitable for in-situ monitoring of samples and rapid processing of multiple samples. The high number and structural diversity of EDCs calls for the urgent development of multiplexed biosensors/sensor arrays integrated with high-throughput sample processing power for monitoring activities (or measuring effects of the EDCs) rather than only the concentration of a single, or a set of, compounds. The objective of this project is to develop high performance microparticle-based assays which will be incorporated in microfluidic devices to create analytical systems that are rationally multiplexed for selective and quantitative detection and discrimination of multiple EDCs and for parallel processing of multiple samples. Specifically, we will develop biomimetic microparticles (BMMPs) that allow detection and discrimination of different EDCs via two distinct and complementary mechanisms. The first mechanism is based on the ability of EDCs to bind with specific endocrine receptors (ERs), with each EDC exhibiting a different and distinct affinity profile towards different types of ERs and ER-like receptors. We will develop a set of BMMPs with different linker-modified estrogen / EDC molecules immobilized on the surfaces, which can bind with different estrogen receptors (ERs) / estrogen-related receptors (ERRs). The receptor proteins will be conjugated with signal-generating and signal-amplifying elements, and competitive binding of EDCs in solution will lead to decrease of signals from the BMMPs. The second mechanism is based on recent studies that many EDCs interact strongly with, and even disrupt, artificial phospholipid bilayer membranes such as liposomes. By creating a set of multiplexed BMMPs, each displaying different phospholipid bilayer membranes with a different chemical character, we will be able to directly detect patterns of membrane partitioning, transport and disruption attributable to particular EDCs, and detect extent of reaction for different EDCs with specific endocrine receptors entrapped in BMMPs. Two separate breakthroughs developed by our research team, microfluidic-based microparticle display technology, and biomimetic microsphere technology, will be combined in a collaborative effort to develop a unique and powerful microanalytical approach that will allow point-of- need, field-based detection and profiling of EDCs. The technology platform may potentially be used for developing multiplexed assays for detection and differentiation of other emerging chemicals of public health concern.