Method and device for producing optimized lipid-based micro/nano-bubbles

Abstract

A method of producing lipid-based micro/nano bubbles includes steps of (a) preparing a lipid mixture including one or more first lipids with different phase transition temperature, and a second lipid bonding with a hydrophilic polymer moiety or molecules capable of getting across a lipid membrane and decreasing van der Waals forces between lipid bilayers; (b) emulsifying the lipid mixture with a solvent, to form a transparent lipid carrier solution; (c) placing the transparent lipid carrier solution in a closed vessel with halo-substituted hydrocarbon; (d) manipulating temperature of the transparent lipid carrier solution to be close to a main phase transition temperature thereof; and (e) agitating in a mechanical manner the vessel containing the transparent lipid carrier solution to form micro/nano bubbles within the closed vessel. This method contributes to form micro/nano bubbles with desired diameters in a way of optimal material utilization efficiency.

What is claimed is: 
     
         1 . A microbubble-containing composition prepared by a process comprising (a) preparing a lipid mixture comprising a first lipid, or two or more first lipids with different phase transition temperature, a second lipid bonding with a hydrophilic polymer moiety and optionally one or more molecules capable of getting across a lipid membrane and decreasing van der Waals forces between lipid bilayers; wherein each of the first lipids includes a hydrophobic C8-C30 end, and the hydrophilic polymer moiety has a long chain with molecular weight of 200-200,000; (b) emulsifying the lipid mixture with an aqueous solvent by mechanical means to form a transparent lipid carrier solution and then adjusting the transparent lipid carrier to 20 Celsius degree; (c) placing the transparent lipid carrier solution in a closed vessel comprising a predetermined gas or a hydrophobic molecule; and (d) manipulating temperature of the transparent lipid carrier solution to be close to a main phase transition temperature of the transparent lipid carrier solution while agitating in a mechanical manner the closed vessel containing the transparent lipid carrier solution to form said microbubble-containing composition. 
     
     
         2 . The composition as claimed in  claim 1 , wherein the hydrophobic C8-C30 end is selected from the groups of linear alkyl chain, alkenyl chain, alkylnyl chain, a fluoroalkyl chain, branched alkyl chain, and the combination thereof. 
     
     
         3 . The composition as claimed in  claim 1 , wherein the first lipid is selected from the group consisting of:
 1,2-dimyristoyl-sn-glycero-3-phosphocholine,   1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine,   1,2-dimyristoyl-sn-glycero-3-phospho-(1′-rac-glycerol),   1,2-dimyristoyl-sn-glycero-3-phosphserine,   1,2-dimyristoyl-sn-glycero-3-phosphate,   1,2-dipalmitoyl-sn-glycero-3-phosphocholine,   1,2-dipalmitoyl-sn-glycero-3-phosphate,   1,2-dipalmitoyl-sn-glycero-3-phosphserine,   1,2-dipalmitoyl-sn-glycero-3-phospho-(1′-rac-glycerol),   1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine,   1,2-distearoyl-sn-glycero-3-phosphocholine,   1,2-distearoyl-sn-glycero-3-phospho-(1′-rac-glycerol),   1,2-distearoyl-sn-glycero-3-phosphoethanolamine,   1,2-distearoyl-sn-glycero-3-phosphate,   1,2-distearoyl-sn-glycero-3-phosphserine,   1,2-dioleoyl-3-trimethylammonium-propane,   1,2-dioleoyl-sn-glycero-3-phosphocholine,   1,2-dioleoyl-sn-glycero-3-phosphoethanolamine,   1,2-dioleoyl-sn-glycero-3-phosphate,   1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol),   1,2-dioleoyl-sn-glycero-3-phosphserine,   1,2-dipalmitoyl-3-trimethylammonium-propane,   1,2-distearoyl-3-trimethylammonium-propane,   dimethyldioctadecylammonium bromide,   1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-diethylenetriaminepentaacetic acid,   1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-diethylenetriaminepentaacetic acid,   myristic acid, palmitic acid, stearic acid, oleic acid, tocopherols, tocotrienols, ascorbyl palmitate, sorbitan esters, glyceryl stearate, glyceryl distearates, glyceryl myristate, glyceryl palmitate, glyceryl oleate, polyoxyethylene propylene glycol stearates, and the combination thereof or derived polymers thereof.   
     
     
         4 . The composition as claimed in  claim 1 , wherein the long chain of the hydrophilic polymer moiety is selected from the group consisting of: polyethylene glycol, polypropylene glycol, polyoxyethylene, polyvinylalcohol, polyvinylpyrrolidone and related copolymers, peptide, DNA, RNA, and a combination thereof. 
     
     
         5 . The composition as claimed in  claim 1 , wherein the second lipid is selected from the group consisting of:
 1,2-dipalmitoyl-sn-glycero-3-phosphoethanol amine-N-[methoxy(polyethylene glycol)-2000],   1,2-dipalmitoyl-sn-glycero-3-phosphoethanol amine-N-[methoxy(polyethylene glycol)-3000],   1,2-dipalmitoyl-sn-glycero-3-phosphoethanol amine-N-[methoxy(polyethylene glycol)-5000],   1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000],   1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-3000],   1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-5000],   polyoxyethylene stearates, polyethylene glycol stearates, TWEEN (Registered Trademark), Myrj™, Atlas™, d-alpha tocopheryl polyethylene glycol 1000 succinate, antibody-conjugated PEG-ylated lipid, peptide-conjugated PEG-ylated lipid, DNA-conjugated PEG-ylated lipid, RNA-conjugated PEG-ylated lipid, biotin-modified PEG-ylated lipid, maleimide-modified PEG-ylated lipid, amine-modified PEG-ylated lipid, and the combination thereof or derived polymers thereof.   
     
     
         6 . The composition as claimed in  claim 1 , wherein the one or more molecules capable of getting across a lipid membrane and decreasing van der Waals forces between lipids is selected from the group consisting of: polyethylene glycol, peptide, albumin, amino acid, sugar alcohols, butane-1,3-diol, propane-1,2,3-triol, propane-1,2-diol, propane-1,3-diol, propan-1-ol, ethane-1,2-diol, ethanol, methanol, dimethyl sulfoxide, and the combination thereof. 
     
     
         7 . The composition as claimed in  claim 1 , wherein the aqueous solvent is water, or normal saline, or buffered saline. 
     
     
         8 . The composition as claimed in  claim 1 , wherein the step of emulsifying the lipid mixture with the aqueous solvent is realized by sonication, high-speed agitation, high-pressure homogenization, or membrane filtration. 
     
     
         9 . The composition as claimed in  claim 1 , wherein the predetermined gas is selected from the group consisting of: halo-substituted hydrocarbon (perfluorocarbon), inert gas, Sulfur hexafluoride, nitrogen, oxygen, and air, or a combination thereof. 
     
     
         10 . The composition as claimed in  claim 1 , wherein the step of agitating in the mechanical manner is realized by sonication, manual shaking, high-speed mechanical agitation, microfluidic device/T-focusing, or co-axial electrohydrodynamic atomization micro-bubbling. 
     
     
         11 . The composition as claimed in  claim 3 , wherein the first lipid is selected from the group consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-sn-glycero-3-phosphate, 1,2-dipalmitoyl-sn-glycero-3-phosphserine, 1,2-dipalmitoyl-sn-glycero-3-phospho-(1′-rac-glycerol), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine, 1,2-distearoyl-sn-glycero-3-phosphocholine, 1,2-distearoyl-sn-glycero-3-phospho-(1′-rac-glycerol), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine, 1,2-distearoyl-sn-glycero-3-phosphate, 1,2-distearoyl-sn-glycero-3-phosphserine, and 1,2-distearoyl-sn-glycero-3-phospho-(1′-rac-glycerol). 
     
     
         12 . The composition as claimed in  claim 11 , wherein the first lipid is selected from the group consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-distearoyl-sn-glycero-3-phosphocholine, and 1,2-distearoyl-sn-glycero-3-phospho-(1′-rac-glycerol). 
     
     
         13 . The composition as claimed in  claim 5 , wherein the second lipid is selected from the group consisting of: 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000], 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-3000], 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-5000], 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000], 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-3000], 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-5000], polyoxyethylene stearates, and polyethylene glycol stearates. 
     
     
         14 . The composition as claimed in  claim 13 , wherein the second lipid is 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000], polyoxyethylene stearates, or polyethylene glycol stearates. 
     
     
         15 . A device for producing the microbubble-containing composition of  claim 1 , comprising: a temperature controlling unit, for manipulating the temperature of the transparent lipid carrier solution to be close to a main phase transition temperature of the transparent lipid carrier solution; and a mechanical agitator, for providing mechanical agitations on the transparent lipid carrier solution; wherein the device is arranged such that the mechanical agitator is used to agitating a closed vessel containing the transparent lipid carrier solution having a temperature close to the main phase transition temperature to form the lipid-based bubbles in the closed vessel. 
     
     
         16 . The device as claimed in  claim 15 , wherein the mechanical agitator includes: a clamp, for clasping the closed vessel containing the lipid mixture dissolved in distilled water; a lever, connected with the clamp to construct a agitating mechanism; a fastener, connected to an end of the lever for restraining the movement of the lever; and a motor, connected with the lever and providing power for a reciprocation motion. 
     
     
         17 . The device as claimed in  claim 15 , further comprising a casing for providing a closed chamber and accommodating the temperature controlling unit, the mechanical agitator, and the closed vessel containing the lipid mixture, and the temperature controlling unit further comprising: a first fan set, for generating an inlet airflow flowing towards the interior of the casing; a second fan set, generating an outlet airflow flowing towards the exterior of the casing; a heating coil, heating the inlet airflow; and a sensor, for detecting a temperature within the casing so as to control the first and the second fan sets; wherein the first fan set and the heating coil are started when the temperature within the casing is to be increased to a target temperature, and the second fan set is started when the temperature within the casing is to be decreased to another target temperature. 
     
     
         18 . The device as claimed in  claim 17 , wherein the sensor is incorporated in the clamp or the lever for detect a temperature within the casing. 
     
     
         19 . The device as claimed in  claim 15 , wherein the temperature controlling unit further comprises a dry heating piece incorporated in the clamp, or the lever, or the casing for increasing the temperature within the casing.