Liposome having an exchangeable component
First Claim
1. A method for increasing the rate of exchange of a bilayer stabilizing component from a liposome formulation to improve multiple dosing, said method comprising:
- (a) producing a first liposome composition having a lipid, a bioactive agent and a first bilayer stabilizing component, wherein said first bilayer stabilizing component is DSPE-PEG2000;
(b) determining the rate of exchange of DSPE-PEG2000 from said first liposome composition using a fluorescent lipid mixing assay; and
(c) preparing a second liposome formulation nearly identical to said first liposome formulation having said lipid, said bioactive agent, but substituting DSPE-PEG2000 from said first liposome composition with a second bilayer stabilizing component having a faster rate of exchanges wherein said second liposome composition results in improved dosing.
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Abstract
The present invention provides a fusogenic liposome comprising a lipid capable of adopting a non-lamellar phase, yet capable of assuming a bilayer structure in the presence of a bilayer stabilizing component; and a bilayer stabilizing component reversibly associated with the lipid to stabilize the lipid in a bilayer structure. Such fusogenic liposomes are extremely advantageous because the rate at which they become fusogenic can be not only predetermined, but varied as required over a time scale ranging from minutes to days. Control of liposome fusion can be achieved by modulating the chemical stability and/or exchangeability of the bilayer stabilizing component(s). The fusogenic liposomes of the present invention can be used to deliver drugs, peptide, proteins, RNA, DNA or other bioactive molecules to the target cells of interest.
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Citations
21 Claims
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1. A method for increasing the rate of exchange of a bilayer stabilizing component from a liposome formulation to improve multiple dosing, said method comprising:
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(a) producing a first liposome composition having a lipid, a bioactive agent and a first bilayer stabilizing component, wherein said first bilayer stabilizing component is DSPE-PEG2000;
(b) determining the rate of exchange of DSPE-PEG2000 from said first liposome composition using a fluorescent lipid mixing assay; and
(c) preparing a second liposome formulation nearly identical to said first liposome formulation having said lipid, said bioactive agent, but substituting DSPE-PEG2000 from said first liposome composition with a second bilayer stabilizing component having a faster rate of exchanges wherein said second liposome composition results in improved dosing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
wherein;
% fusion rate is relative to the % bilayer stabilizing component exchange rate,F(t) is fluorescence intensity at time t of said liposome composition;
FO is fluorescence intensity at zero time of said liposome composition;
FT is fluorescence intensity in the presence of a detergent of said liposome composition;
M(t) is fluorescence intensity at time t for a fused control;
MT is fluorescence intensity in the presence of a detergent of said fused control;
LO is fluorescence intensity at zero time of a light scattering control;
LT is fluorescence intensity in the presence of a detergent of said light scattering control; and
L(t) is fluorescence intensity at time t for said light scattering control.
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Specification