METHOD OF MONITORING THE RELEASE FROM LIPOSOMES OF A PRODUCT OF INTEREST USING SUPERPARAMAGNETIC NANOPARTICLES
The present application relates to a method of monitoring the membrane permeabilization of liposome and the incidental release of a compound of interest.
1 - 13 . (canceled)
14 . A liposome comprising a thermosensitive lipidic membrane encapsulating superparamagnetic nanoparticles the electrostatic surface charge of which is below −20 mV or above +20 mV when measured in an aqueous medium between pH 6 and 8, for use in a method of monitoring the liposome membrane permeabilization and the incidental release of a product of interest, the method comprising:
a) measuring T2*,
b) heating the liposome at Tm or above Tm,
c) measuring T2* after step b),
d) obtaining the r 2* values from the T2* values obtained from step a) and step c),
e) determining the ratio of r 2* before the heating step at Tm or above Tm/r 2* after the heating step at Tm or above Tin, a ratio above 1.5 being indicative of the liposome membrane permeabilization and of the incidental release of the product of interest, thereby monitoring the liposome membrane permeabilization.
15 . A liposome comprising a thermosensitive lipidic membrane encapsulating superparamagnetic nanoparticles the electrostatic surface charge of which is below −20 mV or above +20 mV measured in an aqueous medium between pH 6 and 8, for use in a method of monitoring the liposome membrane permeabilization and the incidental release of a product of interest, the method comprising:
a) measuring T2* and T1,
b) heating the liposome at Tm or above Tm,
c) measuring T2* and T1 after step b),
d) obtaining r 2* and r 1 values from the T2* and T1 values obtained from steps a) and c),
e) determining the ratio of r 2* /r 1 before and after the heating step at Tm or above Tm, a ratio of r 2* /r 1 before the heating step b) and of r 2* /r 1 after the heating step b) above 2 being indicative of the liposome membrane permeabilization and of the incidental release of the product of interest, thereby monitoring the liposome membrane permeabilization.
16 . The liposome according to claim 14 , wherein the liposome is for use in a method as defined in claim 14 further comprising at least one step of measuring T2*, or T2 and T2*, during the heating step b).
17 . The liposome according to claim 15 , wherein the liposome is for use in a method as defined in claim 15 further comprising at least one step of measuring T2* and T1, and optionally T2, during the heating step b).
18 . The liposome according to claim 14 , wherein Tm is between 39° C. and 45° C.
19 . The liposome according to claim 14 , wherein the thermosensitive lipidic membrane comprises at least a phosphatidylcholine.
20 . The liposome according to claim 18 , wherein the thermosensitive lipidic membrane further comprises cholesterol.
21 . The liposome according to claim 19 , wherein the thermosensitive lipidic membrane further comprises distearylphosphatidylethanolamine-methoxypolyethylene glycol.
22 . The liposome according to claim 20 , wherein the thermosensitive lipidic membrane further comprises distearylphosphatidylethanolamine-methoxypolyethylene glycol.
23 . The liposome according to claim 14 , wherein the largest size of the liposome is between 50 and 500 nm or between 50 and 250 nm.
24 . The liposome according to claim 14 , wherein the nanoparticles are covalently or electrostatically fully coated with an agent selected from a carboxylic acid, a phosphate and an amine agent.
25 . The liposome according to claim 14 , wherein the nanoparticles are prepared from iron oxide such magnetite and/or maghemite.
26 . The liposome according to claim 14 , wherein the nanoparticle largest size is between 2 and 30 nm or between 2 and 20 nm.
27 . The liposome according to claim 14 , wherein the product of interest is selected from a therapeutic nucleic acid, a cytostatic compound, and a cytotoxic compound.