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Dependence of norfloxacin diffusion across bilayers on lipid composition
Sowmya Purushothaman1, Jehangir Cama, Ulrich F Keyser
1Biological and Soft Systems, Department of Physics, University of Cambridge, Cavendish Laboratory, JJ Thomson Avenue, Cambridge, CB3 0HE, UK. ufk20@cam.ac.uk.
Soft Matter
|January 16, 2016
Summary
Understanding how drugs cross cell membranes is key to fighting antibiotic resistance. This study shows drug diffusion depends on specific lipid interactions, not just overall partitioning, guiding new antibiotic design.
Area of Science:
- Biophysics
- Drug Delivery
- Antimicrobial Resistance
Background:
- Antibiotic resistance necessitates novel drug development.
- Efficient drug uptake via passive diffusion is crucial but hindered by poor understanding of drug-membrane interactions.
- Developing new drugs requires facile tools to probe drug-lipid biophysical interactions.
Purpose of the Study:
- To investigate the passive membrane permeability of autofluorescent antibiotics using a label-free microfluidic platform.
- To examine the influence of specific lipid compositions on drug diffusion across giant unilamellar lipid vesicles.
- To provide a label-free method for measuring passive membrane permeability and drug-lipid interactions.
Main Methods:
- Utilized a label-free microfluidic platform integrated with giant unilamellar lipid vesicles.
- Investigated membrane permeability across lipid mixtures of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and 1,2-dioleoyl-sn-glycero-3-phosphoglycerol (DOPG) in 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC).
- Employed norfloxacin, a fluoroquinolone antibiotic, as a case study for autofluorescent drug permeability measurements.
Main Results:
- Norfloxacin diffusion rate is significantly influenced by the specific lipid composition of the membrane.
- Anionic lipids like DOPG were found to impede norfloxacin diffusion.
- Increased concentrations of DOPE enhanced the diffusion of norfloxacin across lipid bilayers.
- Results deviate from predictions based on traditional octanol-lipid partition coefficient assays.
Conclusions:
- Drug diffusion across cellular membranes is highly dependent on specific drug-lipid interactions, not solely on overall lipid partitioning.
- Investigating the specificity of drug interactions with membrane lipids is essential for effective drug delivery and targeted drug development.
- This label-free approach offers a valuable tool for characterizing drug permeability and guiding the design of new antibiotics to combat resistance.
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