Stabilized nanobubbles and microbubbles for diagnostic and therapeutic applications
A composition includes a plurality of stabilized nanobubbles and/or microbubbles. Each nanobubble and/or microbubble has a lipid membrane that defines at least one internal void, which includes at least one gas, the membrane including a plurality of lipids, an edge-activator, which is incorporated between lipids of the membrane and enhances the flexibility of the nanobubbles and/or microbubbles, and a membrane stiffener, which is incorporated on an outer surface of the membrane and enhances the membranes resistance to tearing.
1 . A composition comprising:
a plurality of stabilized nanobubbles, each nanobubble having a lipid membrane that defines at least one internal void, which includes at least one gas, the membrane of each nanobubble consisting essentially of a plurality of lipids, which are a mixture of dibehenoylglycerophosphocoline (DBPC), dipalmitoylphosphatidic acid (DPPA), dipalmitoylphosphatidylethanolamine (DPPE), and PEG functionalized distearoylphosphatidylethanolamine (DSPE); propylene glycol that is incorporated between lipids of the membrane; and glycerol that is incorporated on an outer surface of the membrane, wherein the nanobubbles have an average diameter of about 30 nm to about 600 nm, the propylene glycol is the only cosurfactant or surfactant incorporated in the membrane besides the plurality of lipids, and the stabilized nanobubbles have a lipid concentration of at least 5 mg/ml.
2 . The composition of claim 1 , wherein the mixture includes at least about 50% by weight of dibehenoylglycerophosphocoline (DBPC) and less than about 50% by weight of dipalmitoylphosphatidylethanolamine (DPPE), PEG functionalized distearoylphosphatidylethanolamine (DSPE), and dipalmitoylphosphatidic acid (DPPA).
3 . The composition of claim 1 , wherein the mixture of dibehenoylglycerophosphocoline (DBPC), dipalmitoylphosphatidic acid (DPPA), dipalmitoylphosphatidylethanolamine (DPPE), and distearoylphosphatidylethanolamine-N-methoxy-polyethylene glycol (DSPE-mPEG) are at a weight ratio of about 6:1:2:1.
4 . The composition of claim 1 , further comprising at least one targeting moiety that is linked to the membrane of each nanobubble.
5 . The composition of claim 4 , the targeting moiety being selected from the group consisting of polypeptides, polynucleotides, small molecules, elemental compounds, antibodies, and antibody fragments.
6 . The composition of claim 1 , further comprising at least one therapeutic agent that is contained within the membrane or conjugated to the membrane of each nanobubble.
7 . The composition of claim 6 , the therapeutic agent further comprising at least one chemotherapeutic agent, anti-proliferative agent, biocidal agent, biostatic agent, or anti-microbial agent.
8 . A method for imaging a region of interest (ROI) in a subject, the method comprising the steps of:
administering to the subject a plurality of stabilized nanobubbles of claim 1 ; and
generating at least one image of the ROI by nonlinear ultrasound imaging the nanobubbles in the ROI.
9 . The method of claim 8 , the step of administering the composition to the subject further comprising the step of generating at least one baseline image of the ROI prior to administering the composition.
10 . A method of assessing vascular permeability of vasculature of a subject in need thereof, the method comprising:
administering to the subject a plurality of stabilized nanobubbles of claim 1 ; and
generating at least one intravascular and/or extravascular ultrasound image to determine extravasation of the nanobubbles and permeability of the vasculature.
11 . The composition of claim 1 , wherein the membrane consists of a plurality of lipids, which are a mixture of dibehenoylglycerophosphocoline (DBPC), dipalmitoylphosphatidic acid (DPPA), dipalmitoylphosphatidylethanolamine (DPPE), and PEG functionalized distearoylphosphatidylethanolamine (DSPE); propylene glycol that is incorporated between lipids of the membrane; and glycerol that is incorporated on an outer surface of the membrane.