Herein, we present a modular droplet-based microfluidic approach for performing high throughput c... more Herein, we present a modular droplet-based microfluidic approach for performing high throughput cytotoxicity screening of photosensitizers against microbial organisms. Multiple novel fluidic operation modalities such as large-scale chamber based light irradiation, reinjection and low voltage driven electrocoalescence are introduced. Also, photosensitiser drug cytotoxicity on E.coli cells are evaluated in microfluidic device using fluorescent viability assay indicator and compared with conventional colony forming unit counting cytotoxicity assay.
Microfluidic systems are pervasive in many areas of experimental science, but what are the real a... more Microfluidic systems are pervasive in many areas of experimental science, but what are the real advantages of this technology? We describe some of the features and properties that make microfluidic devices unique experimental tools. In addition to pointing out some of the less effective uses of this technology, we assess the most successful applications of microfluidics over the last two decades and highlight the areas where they had the greatest impact. We also propose applications where microfluidic systems could be applied to the greatest effect in the future.
Quantifying the impact of environmental physicochemical changes on the micro-structure of lipid d... more Quantifying the impact of environmental physicochemical changes on the micro-structure of lipid delivery systems is challenging. We have therefore developed a methodology to quantify the coalescence of oil-in-water emulsion droplets during lipid digestion in situ on a single droplet level. This technique involves a custom-made glass microfluidic platform, in which oil droplets can be trapped as single droplets, or several droplets per trap, the physicochemical environment can be controlled, and droplet digestion, as well as coalescence, can be visualized. We show that the exchange of the physicochemical conditions in the entire reaction chamber can be reached in under 30 s. Microparticle image velocimetry allowed mapping of the flow profile and demonstrated the tuneability of the shear profile in the device. The extraction of quantitative information regarding the physical characteristics of droplets during digestion was performed using automated image analysis throughout the digest...
A novel approach to the monitoring and analysis of bubbles in gas/liquid binary systems is descri... more A novel approach to the monitoring and analysis of bubbles in gas/liquid binary systems is described. The method is based on the varying extent of refraction experienced by radiation as it passes through a gas or liquid. Specifically, carbonated liquids are hydrodynamically motivated through a microfluidic channel network (40 µm wide and 30 µm deep) and directed through the path
ABSTRACT Current methods for screening libraries of compounds for biological activity are rather ... more ABSTRACT Current methods for screening libraries of compounds for biological activity are rather cumbersome, slow and imprecise. A method that breaks up a continuous flow of a compound's solution into droplets offers radical improvements.
A microfluidic droplet-handling architecture for the synchronization of asynchronous, mis-matched... more A microfluidic droplet-handling architecture for the synchronization of asynchronous, mis-matched, pre-formed droplet streams is demonstrated.
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
A poster of the droplet failure modes and suggested ameliorations strategies is provided separate... more A poster of the droplet failure modes and suggested ameliorations strategies is provided separately. This Supplementary Information (SI) contains: 1) an annotated image of the microfluidic device design with dimensions, 2) a detailed Materials and methods section, 3) a tabulated database of all experimental data acquired with the acquisition conditions and the observed droplet failure modes for each experiment, 4) a list of the experimental conditions used in the images and videos of each droplet failure mode (videos of nineteen of the twenty droplet failure modes are provided separately), 5) experimental data to show how the model predicts device wettability, 6) an explanation for micelle "evaporation" in droplet systems, 7) an additional image of droplet budding,
... 2 (2000), p. 157. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (184). ... more ... 2 (2000), p. 157. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (184). [7] TG Schaaff, MN Shafigullin, JT Khoury, I. Vezmar, RL Whetten, WG Cullen, PN First, C. Gutiérrez-Wing, J. Ascensio and MJ Jose-Yacamán, J. Phys. Chem., B 101 (1997), p. 7885. ...
Monolithic microfluidic reactors for the safe, expedient, and continuous synthesis of products in... more Monolithic microfluidic reactors for the safe, expedient, and continuous synthesis of products involving unstable intermediates were fabricated and assessed. The formation of diazonium salts in anhydrous conditions and their subsequent in situ chlorination within microfluidic channels under hydrodynamic pumping regimes is presented. Significant enhancements in yield were observed due to enhanced heat and mass transfer in microfluidic systems. Analysis performed using off-line GC and GC-MS was compared with on-line, on-chip Raman spectroscopy for the direct determination of analytes.
Singlet oxygen, a reactive oxygen species, has been a basic synthetic tool in the laboratory for ... more Singlet oxygen, a reactive oxygen species, has been a basic synthetic tool in the laboratory for many years. It can be generated either through a chemical process or, most commonly, via a photochemical process mediated by a sensitising dye. The relative paucity of singlet oxygen employment in fine chemical industrial settings can be attributed to many factors,
An extremely rapid tool for continuous flow synthetic process optimisation is described. A microf... more An extremely rapid tool for continuous flow synthetic process optimisation is described. A microfluidic reaction system operating in continuous flow is used in conjunction with confocal Raman microscopy to afford rapid molecule synthesis and product quantitation. Accordingly, the approach allows for rapid reaction optimisation within a continuous flow system. Specifically, the catalytic oxidation of isopropyl alcohol (IPA) to acetone using tetra-N-propylammonium perruthanate (TPAP)/N-methylmorpholine N-oxide (NMO) in a radial interdigitated micromixer is studied as a model reaction system. The composition of the reaction effluent can be determined with great facility and information relating to catalyst/co-oxidant ratios, catalyst turnovers and reaction endpoints extracted. Specifically, variation of catalyst and co-oxidant volumetric flow rates between 0 and 50 microL min(-1) is used to vary reactant concentrations, define reaction residence times and control product conversions between 0 and 100%. The rapid nature of the system allows chemical information to be gathered and utilised on a sub-minute timescale.
ÐA route to homochiral 2-substituted chromanones via the diastereoselective conjugate addition of... more ÐA route to homochiral 2-substituted chromanones via the diastereoselective conjugate addition of organocopper reagents to 3-(p-tolylsul®nyl)chromones has been improved and used to prepare 2,6-dimethylchromanone (S)-4 and LL-D253a methyl ether (S)-6. The attempted preparation of a 2-phenylchromanone (¯avanone) using this strategy was unsuccessful due to the lability of the intermediate 2phenyl-3-(p-tolylsul®nyl)chromanone, which underwent sulfoxide elimination at room temperature to give the corresponding 2-phenylchromone (¯avone).
Herein, we present a modular droplet-based microfluidic approach for performing high throughput c... more Herein, we present a modular droplet-based microfluidic approach for performing high throughput cytotoxicity screening of photosensitizers against microbial organisms. Multiple novel fluidic operation modalities such as large-scale chamber based light irradiation, reinjection and low voltage driven electrocoalescence are introduced. Also, photosensitiser drug cytotoxicity on E.coli cells are evaluated in microfluidic device using fluorescent viability assay indicator and compared with conventional colony forming unit counting cytotoxicity assay.
Microfluidic systems are pervasive in many areas of experimental science, but what are the real a... more Microfluidic systems are pervasive in many areas of experimental science, but what are the real advantages of this technology? We describe some of the features and properties that make microfluidic devices unique experimental tools. In addition to pointing out some of the less effective uses of this technology, we assess the most successful applications of microfluidics over the last two decades and highlight the areas where they had the greatest impact. We also propose applications where microfluidic systems could be applied to the greatest effect in the future.
Quantifying the impact of environmental physicochemical changes on the micro-structure of lipid d... more Quantifying the impact of environmental physicochemical changes on the micro-structure of lipid delivery systems is challenging. We have therefore developed a methodology to quantify the coalescence of oil-in-water emulsion droplets during lipid digestion in situ on a single droplet level. This technique involves a custom-made glass microfluidic platform, in which oil droplets can be trapped as single droplets, or several droplets per trap, the physicochemical environment can be controlled, and droplet digestion, as well as coalescence, can be visualized. We show that the exchange of the physicochemical conditions in the entire reaction chamber can be reached in under 30 s. Microparticle image velocimetry allowed mapping of the flow profile and demonstrated the tuneability of the shear profile in the device. The extraction of quantitative information regarding the physical characteristics of droplets during digestion was performed using automated image analysis throughout the digest...
A novel approach to the monitoring and analysis of bubbles in gas/liquid binary systems is descri... more A novel approach to the monitoring and analysis of bubbles in gas/liquid binary systems is described. The method is based on the varying extent of refraction experienced by radiation as it passes through a gas or liquid. Specifically, carbonated liquids are hydrodynamically motivated through a microfluidic channel network (40 µm wide and 30 µm deep) and directed through the path
ABSTRACT Current methods for screening libraries of compounds for biological activity are rather ... more ABSTRACT Current methods for screening libraries of compounds for biological activity are rather cumbersome, slow and imprecise. A method that breaks up a continuous flow of a compound's solution into droplets offers radical improvements.
A microfluidic droplet-handling architecture for the synchronization of asynchronous, mis-matched... more A microfluidic droplet-handling architecture for the synchronization of asynchronous, mis-matched, pre-formed droplet streams is demonstrated.
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
A poster of the droplet failure modes and suggested ameliorations strategies is provided separate... more A poster of the droplet failure modes and suggested ameliorations strategies is provided separately. This Supplementary Information (SI) contains: 1) an annotated image of the microfluidic device design with dimensions, 2) a detailed Materials and methods section, 3) a tabulated database of all experimental data acquired with the acquisition conditions and the observed droplet failure modes for each experiment, 4) a list of the experimental conditions used in the images and videos of each droplet failure mode (videos of nineteen of the twenty droplet failure modes are provided separately), 5) experimental data to show how the model predicts device wettability, 6) an explanation for micelle "evaporation" in droplet systems, 7) an additional image of droplet budding,
... 2 (2000), p. 157. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (184). ... more ... 2 (2000), p. 157. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (184). [7] TG Schaaff, MN Shafigullin, JT Khoury, I. Vezmar, RL Whetten, WG Cullen, PN First, C. Gutiérrez-Wing, J. Ascensio and MJ Jose-Yacamán, J. Phys. Chem., B 101 (1997), p. 7885. ...
Monolithic microfluidic reactors for the safe, expedient, and continuous synthesis of products in... more Monolithic microfluidic reactors for the safe, expedient, and continuous synthesis of products involving unstable intermediates were fabricated and assessed. The formation of diazonium salts in anhydrous conditions and their subsequent in situ chlorination within microfluidic channels under hydrodynamic pumping regimes is presented. Significant enhancements in yield were observed due to enhanced heat and mass transfer in microfluidic systems. Analysis performed using off-line GC and GC-MS was compared with on-line, on-chip Raman spectroscopy for the direct determination of analytes.
Singlet oxygen, a reactive oxygen species, has been a basic synthetic tool in the laboratory for ... more Singlet oxygen, a reactive oxygen species, has been a basic synthetic tool in the laboratory for many years. It can be generated either through a chemical process or, most commonly, via a photochemical process mediated by a sensitising dye. The relative paucity of singlet oxygen employment in fine chemical industrial settings can be attributed to many factors,
An extremely rapid tool for continuous flow synthetic process optimisation is described. A microf... more An extremely rapid tool for continuous flow synthetic process optimisation is described. A microfluidic reaction system operating in continuous flow is used in conjunction with confocal Raman microscopy to afford rapid molecule synthesis and product quantitation. Accordingly, the approach allows for rapid reaction optimisation within a continuous flow system. Specifically, the catalytic oxidation of isopropyl alcohol (IPA) to acetone using tetra-N-propylammonium perruthanate (TPAP)/N-methylmorpholine N-oxide (NMO) in a radial interdigitated micromixer is studied as a model reaction system. The composition of the reaction effluent can be determined with great facility and information relating to catalyst/co-oxidant ratios, catalyst turnovers and reaction endpoints extracted. Specifically, variation of catalyst and co-oxidant volumetric flow rates between 0 and 50 microL min(-1) is used to vary reactant concentrations, define reaction residence times and control product conversions between 0 and 100%. The rapid nature of the system allows chemical information to be gathered and utilised on a sub-minute timescale.
ÐA route to homochiral 2-substituted chromanones via the diastereoselective conjugate addition of... more ÐA route to homochiral 2-substituted chromanones via the diastereoselective conjugate addition of organocopper reagents to 3-(p-tolylsul®nyl)chromones has been improved and used to prepare 2,6-dimethylchromanone (S)-4 and LL-D253a methyl ether (S)-6. The attempted preparation of a 2-phenylchromanone (¯avanone) using this strategy was unsuccessful due to the lability of the intermediate 2phenyl-3-(p-tolylsul®nyl)chromanone, which underwent sulfoxide elimination at room temperature to give the corresponding 2-phenylchromone (¯avone).
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