Hi,
I’m trying to encapsulate an enzyme in liposomes.
we already have a phospholipid formula validated in previous projects. But now we are trying to use this formula with an enzyme. How can we know when liposomes are formed? Or calculate how many enzyme is encapsulated and how many remains free in the solution?
thanks in advance!
Dear Marc Alemany Fornes
In your question, you mentioned:
"... we already have a phospholipid formula validated in previous projects ..."
"How can we know when liposomes are formed?"
What exactly you mean by saying "... validated phospholipid formula ..."?
Is this "phospholipid formula" in the form of a bilayer vesicle (i.e. liposome)?
If you have already validated a liposomal formulation, what techniques you used for validation?
The general practice is to use a combination of (not a single method) particle sizing techniques and visualisation techniques (e.g., TEM, SEM, STM, AFM, Confocal microscopy, etc.) to validate and confirm formation of liposomes / nanoliposomes.
The other part of your question is: " ... calculate how many enzyme is encapsulated and how many remains free in the solution?
For this you must calculate Encapsulation Efficiency / Drug Loading Capacity by quantifying the un-encapsulated enzymes after performing an appropriate separation procedure.
The following papers may provide more explanation to your questions:
Microscopical investigations of nisin-loaded nanoliposomes prepared by Mozafari method and their bacterial targeting
JC Colas, W Shi, VSNM Rao, A Omri, MR Mozafari, H Singh (2007)
Micron 38 (8), 841-847.
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The role of high-resolution imaging in the evaluation of nanosystems for bioactive encapsulation and targeted nanotherapy
K Khosravi-Darani, A Pardakhty, H Honarpisheh, V Rao, MR Mozafari (2007)
Micron 38 (8), 804-818
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Sample protocols for the preparation and characterisation of lipid vesicles
MR Mozafari, J Flanagan, X Zhu, RI Zhdanov (2005)
Nanoliposomes: From Fundamentals to Recent Developments, 125-145
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There are several methods that can be used to determine when liposomes are formed and to calculate the amount of enzyme encapsulated within them. One common method is dynamic light scattering (DLS), which can be used to measure the size and number of particles in a sample. Another method is transmission electron microscopy (TEM), which can be used to visualize the liposomes and estimate their size and number. Additionally, enzyme activity assays can be used to measure the amount of enzyme encapsulated within the liposomes, and the difference in activity between the liposomes and free enzyme can be used to calculate the amount of enzyme encapsulated. Additionally, Fluorescence spectroscopy can also be used to measure the amount of enzyme encapsulated within liposomes.
Hi:
I have used Glucose Oxidase (GOD) in my thesis. I have encapsulated GOD in liposomes and tried to calculate encapsulation efficiency.
https://www.academia.edu/1284213/Enzyme_immobilization_in_polymer_coated_liposomes
I hope this helps you.
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