Liposome Calculator

Liposome Calculator is a scientific tool available on Apple Store for iOS and Mac, that helps fully parameterize complex lipid mixture systems, providing user with complete information regarding preparation procedure. This application enables calculation of concentrations (molarity and mg/ml), component moles, final solution volume etc., based upon initial data provided, such as: initial concentrations of the stock solutions, initial volumes and desired molar ratios and target molar concentration.

This application follows the common liposome preparation procedure (see the detailed post):

1. Stock solutions of lipids (or any other compound) are mixed in appropriate molar ratios.
2. Obtained mixture is purged with nitrogen and organic solvent is finally evacuated under vacuum.
3. Obtained lipid mixture is hydrated and extruded or sonicated, according to the needs.

Application features:

Unlimited number of components is available. Additional components are added by pressing “Solutions# (+)” field and deleted by pressing the “Molar% (-)” field.

Application includes database for storing molecular weights of the frequently used compounds.

Upon typing the solute names into component cells the software will suggest to autocomplete with the stored information from the database.

Application is fully interactive: all system parameters are updated immediately after any input from user (if the data is sufficient!). For example: final molar concentration and molar ratios of the components can be adjusted at any time if molar concentrations of starting solutions and final suspension volume are provided. Upon any of the aforementioned changes, the application will calculate the volumes of the initial solutions to fit the desired parameters.

If molecular weights (Mw, units “g/mole”) of solutes are provided as well, then concentrations in the units of grams of solute per litre of solution (“g/l” equivalent to “mg/ml”) can be calculated.

Liposome Analysis Activity. The activity window divided to data panel (left) and results panel (right):

The data panel parameters:

Total Concentration: Total lipid concentration. Automatically uploaded from Liposome Calculator activity and can be corrected at any time.

Total Volume: Total solution volume. Automatically uploaded from Liposome Calculator activity and can be corrected at any time.

Diameter: Average liposome outer diameter in nanometers (one billionth of meter).

Bilayer Thickness: Lipid bilayer thickness in angstroms.

Molecular Area: Single lipid molecule area in square angstroms.

The results panel parameters:

Number of Molecules: Average number of lipid molecules in a single liposome (vesicle).

Number of Liposomes: Average total number of liposomes in the analyzed solution.

Inner Volume: Average volume entrapped in a single liposome.

Surface Area: Average surface area of a single liposome.

Encapsulation Efficiency: In this context is represented by ratio of the total entrapped volume to total solution volume. Look up for the definition in regards to the drug encapsulation.