Dear Patcharidea,

Regarding the measurement of the thickness and elasticity of liposomes, you can apply the procedure proposed by :

Mao, G., Liang, X., & Ng, K. S. (2004). Direct force measurement of liposomes by atomic force microscopy. In Dekker Encyclopedia of Nanoscience and Nanotechnology (pp. 933-942). New York: Marcel Dekker.

You need to implement Atomic Force Microscopy (AFM) which is an available instrument, what is more, you can get high-quality images indicating the surface and height properties of the prepared liposomes.

Best.

Iman

Dear Patcharida,

the most direct and likely precise way of measuring membrane thickness is performing electron microscopy on your samples. Other methods are typically more indirect, but can be useful too.

About elasticity, it probably depends you have available.

One possibility could be as answered above using AFM. Other possibilities include using micropipette aspiration, electrodeformation or flicker spectroscopy.

Maybe the following reference might be of some help:

Article Active probing of the mechanical properties of biological an...

Dear Iman Katouzian

Thank you for your technical and informative answer.

Dear Dr Rafael Lira

Thanks a lot for your answer. I will have a look at the paper soon.

Hi,

Apart from Microscopic techniques you can use NMR to measure membrane (bilayer) thickness.

Paper on NMR:

Membrane thickness and molecular ordering in Acholeplasma laidlawii strain A studied by 2H NMR spectroscopy.

R L Thurmond 1, A R Niemi, G Lindblom, A Wieslander, L Rilfors

Affiliations expand

PMID: 7947725

DOI: 10.1021/bi00249a004

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Ipsen, J. H., Mouritsen, O. G., & Bloom, M. (1990). Relationships between lipid membrane area, hydrophobic thickness, and acyl-chain orientational order. The effects of cholesterol. Biophysical journal, 57(3), 405-412.

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Microscopic techniques papers:

Hochmuth, R. M., Evans, C. A., Wiles, H. C., & McCown, J. T. (1983). Mechanical measurement of red cell membrane thickness. Science, 220(4592), 101-102.

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Mozafari, M. R., Reed, C. J., Rostron, C., & Hasirci, V. (2005). A review of scanning probe microscopy investigations of liposome-DNA complexes. Journal of liposome research, 15(1-2), 93-107.

Thank you dear Prof. M. R. Mozafari

I will go through the papers you mentioned above.

Regarding the other section of your question:

"How to measure the ELASTICITY of vesicles"

Benson suggested the following equation:

E = J (rv/rp) ^2

where E = elasticity, J = amount of suspension extruded in x min, rv = liposome size after extrusion. and. rp = pore size of the filter

Benson, H. A. (2017). Elastic liposomes for topical and transdermal drug delivery. In Liposomes (pp. 107-117). Humana Press, New York, NY.

Also have a look at attached papers.

"Bilayer Elasticity at the Nanoscale: The Need for New Terms"

Anne-Florence Bitbol,

Doru Constantin,

Jean-Baptiste Fournier

Published: November 8, 2012

https://doi.org/10.1371/journal.pone.0048306

Hey Patcharidea,

Somebody likes a precise way for measuring membrane was the EM (electron microscopy).

Another could be using AFM and flicker spectroscopy. Also, M. R. Mozafari mentioned that NMR was also having very useful.

Dear Dr Subham Preetam

Thanks a lot for your answer.