A label-free microfluidic assay to quantitatively study antibiotic diffusion through lipid membranes

Cama, Jehangir; Chimerel, Catalin; Pagliara, Stefano; Javer, Avelino; Keyser, Ulrich F.

doi:10.1039/c4lc00217b

Cited by 36 publications

(104 citation statements)

References 34 publications

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“…In our vesicle based assay, however, we can directly observe the concentration of the drug surrounding the vesicles via the autofluorescence of the drug molecules. In our previously published work, we imaged the cross section of a vesicle suspended in a bath of norfloxacin in a confocal microscope; we found no evidence for a large (micron scale) UWL surrounding the vesicles4. Similar single vesicle fluorescence experiments were also previously performed to study the transport (or lack thereof) of indole and indole acetic acid across lipid vesicle membranes.…”

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confidence: 53%

“…For example, the pH of the surrounding environment plays a major role on a drug’s ability to permeate a lipid membrane – at different pH values, the drug molecule can exist in different charge states, which changes its lipophilicity34. This is of particular importance while studying the passage of a drug capsule through the human digestive tract – the pH changes from highly acidic in the stomach (1.0–2.5) to more neutral values (6.5–7.5) in the intestine5.…”

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confidence: 99%

“…We previously developed an optofluidic assay where GUVs are mixed with an antibiotic using a T junction microfluidic chip, the chip being illuminated with ultraviolet (UV) light4. Under UV illumination, many antibiotic molecules are autofluorescent, and can thus be tracked in a label-free manner.…”

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confidence: 99%

“…Under UV illumination, many antibiotic molecules are autofluorescent, and can thus be tracked in a label-free manner. By studying the increase in autofluorescence within the vesicles over time as they pass through the channel in the presence of the antibiotic, we can determine the permeability coefficient of the drug4. Importantly, the technique determines drug permeability directly without requiring the measurement of the octanol partition coefficient.…”

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confidence: 99%

“…Importantly, the technique determines drug permeability directly without requiring the measurement of the octanol partition coefficient. Until now, we have used this technique to study the pH dependence of the transport of norfloxacin, a fluoroquinolone antibiotic, across lipid membranes4. Fluoroquinolones are broad spectrum antibiotics that target intracellular processes catalysed by DNA topoisomerases.…”

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confidence: 99%

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Direct Optofluidic Measurement of the Lipid Permeability of Fluoroquinolones

Cama

Schaich

Nahas

et al. 2016

Sci Rep

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Quantifying drug permeability across lipid membranes is crucial for drug development. In addition, reduced membrane permeability is a leading cause of antibiotic resistance in bacteria, and hence there is a need for new technologies that can quantify antibiotic transport across biological membranes. We recently developed an optofluidic assay that directly determines the permeability coefficient of autofluorescent drug molecules across lipid membranes. Using ultraviolet fluorescence microscopy, we directly track drug accumulation in giant lipid vesicles as they traverse a microfluidic device while exposed to the drug. Importantly, our measurement does not require the knowledge of the octanol partition coefficient of the drug – we directly determine the permeability coefficient for the specific drug-lipid system. In this work, we report measurements on a range of fluoroquinolone antibiotics and find that their pH dependent lipid permeability can span over two orders of magnitude. We describe various technical improvements for our assay, and provide a new graphical user interface for data analysis to make the technology easier to use for the wider community.

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confidence: 53%

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confidence: 99%

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confidence: 99%

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confidence: 99%

mentioning

confidence: 99%

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Direct Optofluidic Measurement of the Lipid Permeability of Fluoroquinolones

Cama

Schaich

Nahas

et al. 2016

Sci Rep

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Microfluidic Handling and Analysis of Giant Vesicles for Use as Artificial Cells: A Review

Robinson

2019

Adv. Biosys.

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One of the goals of synthetic biology is the bottom‐up construction of an artificial cell, the successful realization of which could shed light on how cellular life emerged and could also be a useful tool for studying the function of modern cells. Using liposomes as biomimetic containers is particularly promising because lipid membranes are biocompatible and much of the required machinery can be reconstituted within them. Giant lipid vesicles have been used extensively in other fields such as biophysics and drug discovery, but their use as artificial cells has only recently seen an increase. Despite the prevalence of giant vesicles, many experiments remain challenging or impossible due to their delicate nature compared to biological cells. This review aims to highlight the effectiveness of microfluidic technologies in handling and analyzing giant vesicles. The advantages and disadvantages of different microfluidic approaches and what new insights can be gained from various applications are introduced. Finally, future directions are discussed in which the unique combination of microfluidics and giant lipid vesicles can push forward the bottom‐up construction of artificial cells.

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Lipid Microfluidic Biomimetic Models for Drug Screening: A Comprehensive Review

Fernandes,

Cardoso,

Lanceros‐Méndez

et al. 2024

Adv Funct Materials

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Developing new drugs is a complex, time‐consuming, and expensive process, essential to identify potential pharmacokinetic issues in the early stages to avoid investment in nonpromising candidates. Nearly half of all drug targets and key drug‐metabolizing enzymes are found in intracellular environments, compartmentalized by semipermeable barriers, the cell membranes. Inspired by their lipidic bilayer structure, lipid‐based biomimetic platforms are being developed to understand the biochemical and biophysical processes at the cellular membrane level. Considering the pharmaceutical industry's demands for efficient in vitro high throughput screening tools, microfluidic technology emerges as a promising solution to address challenges in lipid biomimetic models for screening applications. This involves the transformation of commonly used lipid‐based biomimetic models, like supported lipid bilayers and lipid vesicles, to miniaturized approachs and their evolution into a new generation of bilayer models. These include pore‐suspended and free‐standing lipid bilayers, black lipid membranes, and droplet interface bilayers. This review provides an overview of both generations of lipid biomimetic models used in drug‐membrane screening applications. Moreover, it delves into the intricacies of their production through microfluidic approaches and examines their screening applications in drug‐membrane interaction. The review concludes with a critical analysis of potential future directions in this rapidly evolving field.

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A label-free microfluidic assay to quantitatively study antibiotic diffusion through lipid membranes

Cited by 36 publications

References 34 publications

Direct Optofluidic Measurement of the Lipid Permeability of Fluoroquinolones

Direct Optofluidic Measurement of the Lipid Permeability of Fluoroquinolones

Microfluidic Handling and Analysis of Giant Vesicles for Use as Artificial Cells: A Review

Lipid Microfluidic Biomimetic Models for Drug Screening: A Comprehensive Review

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