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A Quantitative Fluorescence Microscopy-based Single Liposome Assay for Detecting the Compositional Inhomogeneity Between Individual Liposomes
Published on: December 13, 2019
Constructing size distributions of liposomes from single-object fluorescence measurements
Christina Lohr1, Andreas H Kunding, Vikram K Bhatia
1Bio-Nanotechnology Laboratory, Department of Neuroscience and Pharmacology and Nano-Science Center, University of Copenhagen, Copenhagen, Denmark.
Methods in Enzymology
|November 17, 2009
Summary
This study presents a simple method for determining liposome size distribution using single-particle fluorescence microscopy. This technique offers detailed insights into complex liposome formulations, surpassing ensemble measurement limitations.
Area of Science:
- Biophysics
- Materials Science
- Nanotechnology
Background:
- Liposome formulations are crucial in drug delivery and diagnostics.
- Accurate characterization of liposome size distribution is essential for their efficacy and safety.
- Traditional methods like dynamic light scattering can average out critical details in complex samples.
Purpose of the Study:
- To introduce a straightforward and accurate technique for constructing liposome size distributions.
- To enable detailed analysis of liposome populations using single-object fluorescence measurements.
- To overcome limitations of ensemble measurement techniques for polydisperse liposome samples.
Main Methods:
- Immobilizing fluorescently labeled liposomes on a surface for individual imaging via epi-fluorescence microscopy.
- Automated image processing using ImageJ software to collect integrated intensities from thousands of single liposomes.
- Scaling intensity data against dynamic light scattering measurements to obtain size distributions in nanometers.
Main Results:
- Successful construction of size distributions from single-liposome fluorescence data.
- Demonstration of the technique's ability to capture details missed by ensemble measurements.
- Accurate characterization of polydisperse liposome samples, including non-extruded preparations.
Conclusions:
- Single-object fluorescence microscopy provides a powerful method for detailed liposome size analysis.
- This technique enhances the characterization of liposome formulations, particularly complex or polydisperse ones.
- The described method offers a user-friendly and efficient approach for obtaining precise liposome size distributions.
