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Biology subjects

Morocz, Y.

Publications and source records attributed to Morocz, Y..

3 recordsLinked to original sources

Multiphase capillarics for structurally pre-programmed sequential and parallel operations of high and low cohesion liquids

Capillaric circuits (CCs) enable pre-programmed liquid handling through self-filling and passive valving governed by capillary forces, eliminating the need for external pumps and actuators. However, CCs optimized for high cohesion liquids (HCL) such as water are intrinsically unsuitable for programmed flow control of low cohesion liquids (LCL) such as oils and solvents because the high surface free energy needed for capillary flow of HCL results in uncontrolled, complete wetting by LCL. Here, we introduce a library of multiphase components including phase-to-phase valves (P2PV), hydro-pneumatic relays (HPR) and multiphase domino valves (MDVs) that collectively enable CCs to concomitantly process HCLs and LCLs. P2PVs use a pre-filled HCL to valve immiscible LCLs (e.g. oil) by confining the LCL, and upon triggering, hydraulically entrain it. To prevent uncontrolled mixing between miscible LCLs (e.g. ethanol) and the HCL, HPRs with an air gap and air waste are added to the P2PV. MDVs are further added and enable preprogrammed, sequential delivery of LCL and HCL by multiphase microfluidic chain reactions. Multiphase liquid processing is applied to automated, on-chip lipid nanoparticle (LNP) manufacturing, illustrating the potential of multiphase CCs.

bioengineering↗

PiP-plex: A Particle-in-Particle System for Multiplexed Quantification of Secreted Proteins by Single Cells

Cell signaling is modulated by the secretion of various proteins, which can be used to infer a cells phenotype. However, these proteins cannot be readily detected in multiplex by commonly used methods at the single cell level. Here, we present PiP-plex, a particles-in-particle (PiPs) system comprising (i) fluorescence intensity barcoded microparticles (BMPs) co-entrapped with (ii) a single cell inside an alginate hydrogel particle for multiplex protein secretion analysis by confocal microscopy. We show that developed PiPs maintained >90 % cellular viability and allowed live cells retrieval. A seven-plex fluorescent barcoding and concomitant sandwich immunoassay in PiPs were implemented with limits of detection ranging from 0.8 pg mL-1 to 2 ng mL-1 depending on the protein. PiP-plex assays were benchmarked with bulk immunoassays and found to rival or outperform them. We applied PiP-plex to analyze protein secreted by THP-1 cells upon exposure to lipopolysaccharide and detected varying cell responses, with a significant increase in MIP-1, TNF- and IL-17A. Multivariate analysis revealed that the majority of stimulated cells secreted either MIP-1 or IL-17A, while other cytokines were typically co-secreted. Using PiP-plex, we analyzed [~]750 THP-1 cells, showcasing its potential for characterizing cells and cell-based therapeutics for cancer immunotherapies.

bioengineering↗

High-resolution low-cost LCD 3D printing of microfluidics

The fabrication of microfluidic devices has progressed from cleanroom manufacturing to replica molding in polymers, and more recently to direct manufacturing by subtractive (e.g., laser machining) and additive (e.g., 3D printing) techniques, notably digital light processing (DLP) photopolymerization. However, many methods require technical expertise and while DLP 3D printers remain expensive at a cost [~]15-30K USD with [~]8M pixels that are 25-40 {micro}m in size. Here, we introduce (i) the use of low-cost ([~]150-600 USD) liquid crystal display (LCD) photopolymerization 3D printing with [~]8M-58M pixels that are 18-35 {micro}m in size for direct microfluidic device fabrication and (ii) a poly(ethylene glycol) diacrylate-based ink developed for LCD 3D printing (PLInk). We optimized PLInk for high resolution, fast 3D printing and biocompatibility while considering the illumination inhomogeneity and low power density of LCD 3D printers. We made lateral features as small as 75 {micro}m, 22-{micro}m-thick embedded membranes, and circular channels with a 110 {micro}m radius. We 3D printed microfluidic devices previously manufactured by other methods, including an embedded 3D micromixer, a membrane microvalve, and an autonomous capillaric circuit (CC) deployed for interferon-{gamma} detection with excellent performance (limit of detection: 12 pg mL-1, CV: 6.8%), and we demonstrated compatibility with cell culture. Finally, large area manufacturing was illustrated by printing 42 CCs with embedded microchannels in <45 min. LCD 3D printing together with tailored inks pave the way for democratizing access to high-resolution manufacturing of ready-to-use microfluidic devices by anyone, anywhere.

bioengineering↗