US 2004/0170565 A1 · Novel ultrasound contrast agents

Abstract

New ultrasound contrast agents that comprise microbubbles encapsulating a gas within a shell made from a blend of bipolar compounds having mixed carbon chain length. The compounds have hydrophobic groups selected from the group consisting of straight-chained alkyls, alkylethers, alkylthiolethers, alkyldisulfides, polyfluoroalkyls, and polyfluoroalkylethers having a carbon chain length greater than or equal to 16 and less than or equal to 32. The polar groups are connected to the hydrophobic groups by means of a linker. The polar head groups are selected from the group consisting of CO2-M+, SO3−M+, SO4−M+, PO3−M+, PO4−M+2, N(R)4+, a pyridinium or substituted pyridinium group, and a zwitterionic group; R is selected from the group consisting of —H, —CH3, alkyl, cycloalkyl, substituted cycloalkyls containing one or more heteroatoms, and benzyl and can be the same or different; and Z′ is a nonionic and M is a cation.

Claims20

Dependent claims

A composition useful as an ultrasound contrast agent comprising microbubbles encapsulating a gas within a shell made from intermolecular regions of blended compounds, said compounds comprised of polar head groups linked to straight-chained hydrophobic groups of differing chain lengths said hydrophobic chains oriented toward the gas phase, whereby the longer chain lengths assemble beneath the shorter chains thereby stabilizing the shell.

The composition of claim 2 wherein the bipolar compounds have the structure:

R1—X-Z;
R2—X-Z;
and R3—X-Z′
where R1, R2 and R3 are hydrophobic groups selected from the group consisting of straight-chained alkyls, alkylethers, alkylthiolethers, alkyldisulfides, polyfluoroalkyls, and polyfluoroalkylethers having a carbon chain length greater than or equal to 16 and less than or equal to 32 and where R1 is greater than R2 and R1 is greater than or equal to R3;
R3 has one or more such hydrophobic groups having the same or different lengths;
X is a linker connecting the hydrophobic group to the polar head group;
Z is a polar head group selected from the group consisting of CO2-M+, SO3−M+, SO4−M+, PO3−M+, PO4−M+2, N(R)4+, a pyridinium or substituted pyridinium group, and a zwitterionic group;
R is selected from the group consisting of —H, —CH3, alkyl, cycloalkyl, substituted cycloalkyls containing one or more heteroatoms, and benzyl and can be the same or different;
and Z′ is a nonionic group.

6 more elements

A method for obtaining an ultrasound contrast image of body tissue comprising:

administering into a body a composition useful as an ultrasound contrast agent comprising microbubbles encapsulating a gas within a shell made from intermolecular regions of blended compounds, said compounds comprised of polar head groups linked to straight-chained hydrophobic groups of differing chain lengths said hydrophobic chains oriented toward the gas phase, whereby the longer chain lengths assemble beneath the shorter chains thereby stabilizing the shell and taking an ultrasound image of the desired tissue.

A method for measuring pressure or fluid flow rates in a closed system comprising:

administering a composition useful for measuring pressure or fluid flow rates comprising microbubbles encapsulating a gas within a shell made from intermolecular regions of blended compounds, said compounds comprised of polar head groups linked to straight-chained hydrophobic groups of differing chain lengths said hydrophobic chains oriented toward the gas phase, whereby the longer chain lengths assemble beneath the shorter chains thereby stabilizing the shell into a closed system, measuring the acoustic changes with frequency for the system;
and calculating the change in pressure or change in fluid flow rate.

Dependencies are inferred from the claim text.

Novel ultrasound contrast agents

Life of this patent

Novel ultrasound contrast agents

Life of this patent

Abstract

Claims20