CN110272867B

CN110272867B - Liquid formulation of streptavidin coupled microbubbles for cell sorting

Info

Publication number: CN110272867B
Application number: CN201910678274.9A
Authority: CN
Inventors: 许晓椿; 魏卿; 肖海蓉; 赵梦莲; 刘庆喜
Original assignee: Shenzhen Boya Perception Pharmaceutical Co ltd
Current assignee: Shenzhen Boya Perception Pharmaceutical Co ltd
Priority date: 2019-07-25
Filing date: 2019-07-25
Publication date: 2023-10-20
Anticipated expiration: 2039-07-25
Also published as: CN110272867A

Abstract

The invention relates to a liquid preparation of streptavidin coupled microbubbles for cell sorting, which is an aerated microbubble suspension in aqueous carrier liquid, wherein the microbubbles are coupled with streptavidin, the diameter of the microbubbles is less than 10 mu m, the number of the streptavidin coupled microbubbles of up to 10-8 microbubbles per 1mL of the aerated microbubble suspension is 1-200 ug of embedding gas in the microbubbles per 1mL of the aerated microbubble suspension. Also relates to the use of the liquid preparation as a separation reagent in a method for separating target cells from peripheral blood. The method for separating target cells from peripheral blood by the liquid preparation is detailed in the specification, can simply, rapidly and efficiently separate and acquire the target cells such as immune cells, hematopoietic stem cells and the like from the peripheral blood, avoids the problems of magnetic bead residue, defects of fluorescein introduction in flow separation and the like of the traditional magnetic bead method, does not need expensive instrument and equipment, has low cost, has little toxicity to the combined target cells and is not easy to inactivate; the purity and activity of the separated cells are high.

Description

Liquid formulation of streptavidin coupled microbubbles for cell sorting

Technical Field

The present invention relates to a method for easily, rapidly and efficiently separating and obtaining target cells such as immune cells, hematopoietic stem cells, etc. from blood, particularly peripheral blood such as whole blood, and to the use of these separated target cells in the treatment of diseases, and in particular to a method for easily, rapidly and efficiently separating immune cells from blood, particularly peripheral blood, of a healthy human body. Examples of the target cells of the present invention include, but are not limited to, T cells such as cd3+ cells, cd4+ cells, cd8+ cells, NK cells such as cd56+ cells, B cells such as cd19+ cells, and hematopoietic stem cells such as cd34+ cells. The invention also relates in particular to liquid formulations of streptavidin-coupled microbubbles for cell sorting.

Background

Immune cells (immunecells) are an important class of cells of the human body, also commonly known as leukocytes, including lymphocytes and various phagocytes, and also specifically lymphocytes that recognize antigens and produce specific immune responses. Lymphocytes are essential components of the immune system and are widely distributed in the body. Researches show that the blood contains abundant lymphocytes, and the cells have the characteristics of immune regulation, self replication and the like, so the blood has been paid attention to. Lymphocytes have natural killing and self-protecting properties, play a key role in treating viral, bacterial and fungal infections, and have great clinical application value in treating cancers.

Immune cells are abundant in blood of healthy human body, but the number of immune cells in the blood is obviously reduced due to age aging, sub-health, disease and other reasons, and proliferation and differentiation capability is also greatly reduced; while immune cells of other healthy people may cause immune rejection when transplanted to a patient; the injury of the immune cells to the patient and other problems encountered during the collection are directly influenced by the clinical application of the immune cells, so that the search for a stable and reliable immune cell acquisition source is an important problem.

Research shows that the fresh blood of healthy people contains a large number of effective immune cells and can be effectively separated, the immune cells from the tissue not only maintain the biological characteristics of the specific immune response of the immune cells, but also have the original and powerful proliferation capacity, and meanwhile, the isolated immune cells are easy to freeze and recover. Since immune cells originate in themselves, the risk of triggering an immune response and causing graft versus host disease is greatly reduced. The probability of infection and transmission of latent viruses and microorganisms is relatively low. The collecting process is simple, and the health collected person is not damaged. The above reasons are sufficient to make isolation of immune cells from blood an efficient way to obtain immune cells.

In recent years, as the immune system is deeply known, research on immunotherapy for treating cancer by using different components of the immune system has made a major breakthrough, and some related medicines pass the examination of the U.S. food and drug administration and are used in clinic. For example, the antibody is used for treating breast cancer, melanoma, lymphoma, acute and chronic leukemia, etc.; treating prostate cancer with a cancer vaccine; the use of cytokines such as interferon and IL2 to enhance a broad immune response; inhibitors of multiple immune checkpoints have also been found. T cells, one of the lymphocytes, play a vital role in the acquired immunity of humans. Mature T cells activate other immune cells, regulate immune function, recognize specific antigens and kill infected or cancerous cells. T cell feedback therapy has long been practiced in the treatment of viral infection cases. Reinfusion tumor body infiltration T cell therapy in clinical trials for treating melanoma prove that T cell reinfusion has a certain curative effect on tumor antigens. How to quickly and efficiently separate enough T cells from blood for treatment by using the prior art is called a core problem and technical difficulty of the current tumor immunity research.

At present, the separation methods of blood immune cells are different, and the steps are complex, so that a certain difficulty exists in obtaining a large number of blood immune cells, and a certain risk exists in collecting blood of patients suffering from diseases. Therefore, there is a need in the art for a simple, efficient method of separating immune cells from blood to meet the needs of medical, scientific, clinical applications, and the like.

Cell sorting (cell sorting) is a technical method to obtain a more uniform cell population. In cell biology research, obtaining a relatively uniform cell population (purified cells) is often a necessary condition for scientific and clinical research. The method for obtaining the cells with certain purity mainly comprises two main technologies, namely culture purification and direct sorting. Culture purification is a more traditional technology, including differential adherence, culture system screening and the like, but the period is relatively long, and the uniformity of the obtained cells is unstable. Cell sorting is a method for rapidly obtaining characteristic cells, and currently, a large number of sorting techniques are used, including density gradient centrifugation, flow cell sorting (FACS), immunomagnetic bead (MACS) sorting, and the like.

The immunomagnetic bead separation technology is based on that cell surface antigen can be combined with a specific monoclonal antibody connected with magnetic beads, cells connected with the magnetic beads through the antibody are adsorbed and retained in a magnetic field in an externally applied magnetic field, and cells without the surface antigen cannot be combined with the specific monoclonal antibody connected with the magnetic beads but are not magnetic and not retained in the magnetic field, so that the cells can be separated. Cell recovery rate and yield of immunomagnetic bead cell separation technology depend on the specificity of monoclonal antibodies connected with magnetic beads to cells and the size (magnetism) of the magnetic beads, however, the yield of too small magnetic beads is not high, and too large magnetic beads can influence cell activity, so that the later detection effect is not ideal. And at present, magnetic beads with micro-scale or nano-scale are mostly adopted in the market, and the method has a plurality of limitations: 1) The specific surface area of the magnetic beads is relatively small, so that the probability of capturing target cells by the magnetic beads is reduced; 2) Due to the granular nature of the magnetic beads, there is a heterogeneous reaction (multiphase reaction) binding between the magnetic beads and the cells, generally requiring a longer time to capture specific target cells; 3) Whether the magnetic beads are micron, nano or magnetic beads, the monodispersity is poor, and aggregation or precipitation of the magnetic beads is easy to generate, so that the activity of cells is reduced; 4) The preparation process of the immune magnetic beads is to directly couple specific antibodies to the surfaces of the magnetic beads, and the properties of the magnetic beads and hydrophobic or hydrophilic groups carried on the surfaces of the magnetic beads easily cause the change of antibody space conception, so that the biological activity of the antibodies is reduced; 5) The high viscosity of the sample can cause nonspecific adsorption of the immunomagnetic beads, so that the target cells with high purity are difficult to obtain; 6) The diameter of the nanometer magnetic beads is generally between 5nm and 1um, and the nanometer magnetic beads are extremely easy to enter the inside of cells due to endocytosis of the cells because of smaller volume, so that the normal biological activity of the cells is influenced, the nanometer magnetic beads are difficult to remove, and the clinical immunotherapy is influenced.

The flow cytometry sorting technology (FACS) uses the sorting function of a flow cytometer, irradiates single cells dyed by fluorescent pigment under high-speed flow state with high-energy laser, deflects under the action of a high-voltage electric field, falls into respective collecting containers, and drops without charging fall into a middle waste liquid container, so as to realize separation of cells. Although the accuracy of flow cell sorting is high, there are still a number of disadvantages: 1) The investment of equipment is large, and a flow cytometer with a sorting function on the market is generally in hundreds of thousands yuan, which undoubtedly causes no small economic pressure on development of scientific research and clinical tests; 2) When a small amount of cells are sorted, the flow type cell sorting accuracy is high and the speed is high. However, if the cell amount exceeds 10≡9, it takes more than 10 hours, and the activity of the sorted cells is greatly affected; 3) The open operation is more, because the flow cytometry is limited in use, the flow cytometry cannot be placed in sterile environments such as clean areas, if the flow cytometry sorting operation is carried out in non-sterile environments, the quality of the cell sample and the culture in the later stage can be influenced to some extent, and even bacteria are infected. Therefore, the flow-sorted sample is difficult to be used for clinical treatment or some scientific experiments requiring strict requirements on the sample; 4) Antibodies adopted in general flow sorting can be labeled with fluorescein, and fluorescein is difficult to remove from sorted cell samples, so that the method can not only influence later experiments, but also restrict the application of clinical treatment.

The prior art discloses methods for separating relevant target cells from peripheral blood, for example CN102876631a (chinese patent application No. 2012103794314) discloses a simple and effective method for extracting immune cells from blood, and a method for cryopreservation and resuscitation for matched use, and a method for amplifying immune cells after resuscitation, which comprises the following steps: whole blood sample pretreatment, ficoll method separation, MNC collection and washing, MNC counting, MNC cryopreservation, cell resuscitation, MNC counting and cell expansion. It is believed that the invention finds that immune cells can be efficiently obtained using extraction, cryopreservation, resuscitation and expansion of specific procedures, which can be used to treat tumors.

For another example, CN104694473a (chinese patent application No. 201510112515.5) discloses a simple and effective method for automatically extracting immune cells from adult peripheral blood, and in particular, relates to a method for automatically extracting immune cells from adult peripheral blood using an AXP fully-automatic cell separation device, and a method for matched cryopreservation and resuscitation, and a method for amplifying immune cells after resuscitation, which includes the following steps: whole blood sample pretreatment, autosegregation, mononuclear cell collection, and optionally detection of the resulting immune cells for at least one of the following: total number of mononuclear cells, single nuclear cell viability, cell contamination, genetic disease, HLA-ABC/DR ligand. It is believed that the invention finds that immune cells can be efficiently obtained using extraction, cryopreservation, resuscitation and expansion of specific procedures, which can be used to treat tumors.

However, a new method for easily, rapidly and efficiently isolating and obtaining target cells such as immune cells, hematopoietic stem cells, etc. from blood, particularly peripheral blood such as whole blood, is still desired by those skilled in the art, and it is expected that these methods can isolate and obtain target cells with the effect of one or more of high recovery rate, high cell viability, high cell purity in a very short time such as 1 hour.

Disclosure of Invention

The present invention aims to provide a method for easily, rapidly and efficiently separating and obtaining target cells such as immune cells and hematopoietic stem cells from blood, particularly peripheral blood such as whole blood. It has surprisingly been found that by the method of the invention relevant target cells can be obtained with one or more technical effects. The present invention has been completed based on such findings.

Specifically, the first aspect of the present invention provides a method for isolating target cells from peripheral blood, comprising the steps of:

(1) Placing peripheral blood subjected to anticoagulation treatment by using an anticoagulant in advance in a test tube, adding a target cell specific antibody marked by using biotin, uniformly mixing, and incubating to mark the target cells by the specific antibody;

(2) Adding streptavidin coupled microbubbles into the test tube, uniformly mixing, incubating to further mark target cells by the microbubbles, and adding phosphate buffer for dilution;

(3) Centrifuging the test tube to separate target cells, wherein the target cells combined with the specific antibodies and the microbubbles float on the upper layer of the liquid, and the target cells not float on the lower part;

(4) Sucking the upper layer liquid containing the target cells to obtain the target cells.

The method according to the first aspect of the invention, wherein the anticoagulant used for anticoagulation treatment of peripheral blood is selected from the group consisting of: ethylenediamine tetraacetic acid and its salts such as EDTA-Na2, EDTA-K3, oxalates such as sodium oxalate, heparin and its salts such as heparin sodium, citric acid and its salts such as sodium citrate. The manipulation of anticoagulants to peripheral blood is common knowledge in the art.

The method according to the first aspect of the invention, wherein the anticoagulant used for anticoagulation treatment of peripheral blood is selected from the group consisting of: EDTA-K2 anticoagulant.

According to the method of the first aspect of the invention, the target cell is selected from: t cells such as cd3+ cells, cd4+ cells, cd8+ cells, NK cells such as cd56+ cells, B cells such as cd19+ cells, hematopoietic stem cells such as cd34+ cells.

According to the method of the first aspect of the invention, the biotin-labeled cell-specific antibody of interest is selected from the group consisting of: CD3 biotin antibody, CD4 biotin antibody, CD8 biotin antibody, CD56 biotin antibody, CD19 biotin antibody, CD34 biotin antibody.

According to the method of the first aspect of the invention, the biotin-labeled cell-specific antibody of interest is selected from the group consisting of: biotin-labeled murine anti-human CD3 antibody, biotin-labeled murine anti-human CD4 antibody, biotin-labeled murine anti-human CD8 antibody, biotin-labeled murine anti-human CD56 antibody, biotin-labeled murine anti-human CD19 antibody, biotin-labeled murine anti-human CD34 antibody. These antibodies can be prepared by methods well known to those skilled in the art, and are also commercially available. In the present invention, biotin-labeled antibodies, particularly those listed above, are used as they are, unless otherwise indicated, all available directly from BD Biosciences.

The method according to the first aspect of the invention, wherein in step (1), 5 to 50ul, e.g. 10 to 40ul, e.g. 10 to 30ul, of antibody is added per 1mL of peripheral blood.

The method according to the first aspect of the invention, wherein in step (1), the incubation is at room temperature for 10 to 45min, e.g. at room temperature for 20 to 40min, e.g. at room temperature for 25 to 35min.

According to the method of the first aspect of the invention, the streptavidin-coupled microbubbles are streptavidin-coupled embedded gas microbubbles.

In the present invention, the term "entrapped gas microbubbles" may also be referred to as "gas-filled microbubbles" or the like, which have the same meaning and are used interchangeably, and refer to a gas-entrapped lipid vesicle.

The method according to the first aspect of the invention, wherein the embedding gas of the embedding gas microbubbles is selected from the group consisting of C3F8, SF6, CF4, freon, N2, CO2, O2, air, in particular from the group consisting of C3F8, SF6, CF4.

The method according to the first aspect of the present invention, wherein in step (2), the streptavidin-coupled microbubbles are entrapped gas microbubbles coupled via streptavidin, and streptavidin-coupled microbubbles corresponding to 0.5 to 20X 10A 7 microbubbles (the term "0.5 to 20X 10A 7 microbubbles" means 7 microbubbles of 0.5 to 20X 10, and similar meaning when similarly expressed herein) are added per 1mL of peripheral blood, for example streptavidin-coupled microbubbles corresponding to 1 to 15X 10A 7 microbubbles, for example streptavidin-coupled microbubbles corresponding to 1 to 10X 10A 7 microbubbles.

The method according to the first aspect of the present invention, wherein in step (2), the streptavidin-coupled microbubbles are streptavidin-coupled microbubbles of the embedding gas, and the streptavidin-coupled microbubbles comprising 1 to 20ug of the embedding gas, for example, the streptavidin-coupled microbubbles comprising 1 to 15ug of the embedding gas, for example, the streptavidin-coupled microbubbles comprising 1 to 10ug of the embedding gas, are added per 1mL of the peripheral blood.

The method according to the first aspect of the invention, wherein in step (2), the incubation is at room temperature for 5 to 30min, e.g. at room temperature for 5 to 25min, e.g. at room temperature for 10 to 20min.

The method according to the first aspect of the present invention, wherein in step (2), the phosphate buffer is an aqueous solution comprising: 0.8-1.2% w/v human serum albumin, 0.8-1.2 mM EDTA, 0.1-0.15M sodium chloride, 2-3 mM potassium chloride, 7.5-8.0 mM disodium hydrogen phosphate, 0.8-1.2 mM potassium dihydrogen phosphate.

The method according to the first aspect of the present invention, wherein in step (2), the phosphate buffer is an aqueous solution comprising: 1% w/v human serum albumin, 1mM EDTA, 0.13M sodium chloride, 2.55mM potassium chloride, 7.7mM disodium hydrogen phosphate, 1mM potassium dihydrogen phosphate.

The method according to the first aspect of the invention, optionally further comprising the steps of:

(5) Placing the upper liquid containing the target cells sucked in the previous step into a container capable of sealing and compressing the internal air, filling the container with air, sealing the container, then compressing the air in the container to 0.05-0.5 times (e.g. 0.05-0.25 times (e.g. 0.05-0.2 times) of the original volume), releasing the pressure if necessary, repeatedly compressing the air, and releasing the gas in the container under reduced pressure to obtain the target cell suspension basically containing no embedding gas. By compressing the target cell suspension, the embedding gas in the microbubbles can be released, and the substances such as phospholipid, polyethylene glycol and palmitic acid which remain in the target cell suspension can be utilized by human bodies, so that the obtained target cell suspension can be safely applied to clinic even if the substances exist.

(6) And freezing the obtained target cell suspension.

The method according to the first aspect of the present invention, wherein the streptavidin-coupled microbubbles of step (2) are formulated as a liquid formulation of streptavidin-coupled microbubbles for cell sorting according to any of the embodiments of the second aspect of the present invention or as a lyophilized formulation of streptavidin-coupled microbubbles for cell sorting according to any of the embodiments of the third aspect of the present invention added with an aqueous carrier liquid.

Further, the second aspect of the present invention relates to a liquid preparation of streptavidin coupled microbubbles for cell sorting, which is an aerated suspension of microbubbles in an aqueous carrier liquid, wherein the microbubbles are coupled to streptavidin, the diameter of the microbubbles is in the range of 0.2-10 μm, 0.5-200 x 10-8 microbubbles per 1mL of aerated suspension of streptavidin coupled microbubbles are contained, and the amount of entrapped gas in the microbubbles per 1-200 ug of aerated microbubbles suspension is 1-200 ug.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the microbubbles have a diameter size in the range of 1-10 μm.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention comprises 1-150 x 10-8 microbubbles of streptavidin-coupled microbubbles per 1mL of the suspension of gas-filled microbubbles.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention comprises 1-100 x 10-8 microbubbles of streptavidin-coupled microbubbles per 1mL of the suspension of gas-filled microbubbles.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention has an amount of entrapped gas in the microbubbles of 5-150 ug per 1mL of the suspension of gas-filled microbubbles.

The liquid preparation of streptavidin-coupled microbubbles according to the second aspect of the invention has an amount of entrapped gas in the microbubbles of 10-100 ug per 1mL of the suspension of gas-filled microbubbles.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the entrapped gas is selected from the group consisting of C3F8, SF6, CF4, freon, N2, CO2, O2, air, in particular from the group consisting of C3F8, SF6, CF4.

A liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the microbubbles are comprised of a material selected from the group consisting of: phospholipid, polyethylene glycol with molecular weight of 2000-6000 and fatty acid.

A liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the microbubbles are comprised of a material selected from the group consisting of: 10 parts of phospholipid, 200-2000 parts of polyethylene glycol with molecular weight of 2000-6000 and 0.2-5 parts of fatty acid.

A liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the microbubbles are comprised of a material selected from the group consisting of: 10 parts of phospholipid, 250-1500 parts of polyethylene glycol with the molecular weight of 2000-6000 and 0.25-2.5 parts of fatty acid.

A liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the microbubbles are comprised of a material selected from the group consisting of: 10 parts of phospholipid, 500-1000 parts of polyethylene glycol with molecular weight of 2000-6000 and 0.5-2 parts of fatty acid.

A liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the microbubbles are comprised of a material selected from the group consisting of: 10 parts of phospholipid, 600-800 parts of polyethylene glycol with molecular weight of 2000-6000 and 0.75-1.5 parts of fatty acid.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the polyethylene glycol has a molecular weight of 3000 to 5000, for example the polyethylene glycol is polyethylene glycol 4000.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the aqueous carrier liquid is selected from the group consisting of: water, 0.9% sodium chloride solution, 5% dextrose solution, preferably 0.9% sodium chloride solution.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention comprises 10-200 ug, e.g. 20-150 ug, e.g. 50-100 ug, of phospholipid per 1 ml.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the phospholipid is selected from the group consisting of: lecithins such as phosphatidic acid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, cardiolipin and sphingomyelin are exemplified by di-arachidylphospholipid choline (DAPC), di-stearylphospholipid choline (DSPC, 1, 2-Distearoyl-sn-glycero-3-phosphaline), di-palmitoyl phosphatidylglycerol (acid form, DPPG) or sodium salt thereof (DPPG-Na, 1, 2-Dipalmitoyl-sn-glycero-3-phosphate-rac-glycerol sodium (DPPG-Na), di-palmitoyl phosphatidic acid (DPPA).

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the phospholipid is both DSPC and DPPG-Na. For example, DSPC and DPPG-Na are both present in a weight ratio of 1:0.2 to 5, for example, both DSPC and DPPG-Na in a weight ratio of 1: 0.5-2, for example, both DSPC and DPPG-Na in a weight ratio of 1: 1.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the microbubbles are coupled with streptavidin, the weight ratio of phospholipid to streptavidin is 100:0.01 to 0.2. In general, the coupling amount of streptavidin may vary widely depending on the use environment.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention, wherein the fatty acid is selected from palmitic acid, stearic acid, oleic acid.

The liquid formulation of streptavidin-coupled microbubbles according to the second aspect of the invention is prepared by: taking the freeze-dried preparation of the streptavidin coupled microbubbles for cell sorting according to any one of the third aspect of the invention, injecting aqueous carrier liquid into a glass bottle through a puncture rubber plug of a syringe, and severely oscillating to dissolve and suspend the content of the glass bottle, thus obtaining the inflated microbubble suspension, namely the liquid preparation of the streptavidin coupled microbubbles.

Further, a third aspect of the present invention provides a lyophilized formulation of streptavidin-coupled microbubbles for cell sorting comprising a glass vial sealed with a rubber stopper, the vial containing therein a lyophilized powder capable of forming microbubbles upon encountering an aqueous carrier fluid, and the spatial atmosphere within the vial being an embedding gas for inclusion in the microbubbles selected from the group consisting of: C3F8, SF6, CF4, freon, N2, CO2, O2, air (especially selected from C3F8, SF6, CF 4); the microbubbles are coupled to streptavidin and are comprised of a material selected from the group consisting of: polyethylene glycol with molecular weight of 2000-6000, phospholipid and fatty acid.

According to the lyophilized preparation of the third aspect of the present invention, the aqueous carrier liquid is used to dissolve the formed suspension of gas-filled microbubbles (for example, the aqueous carrier liquid is added in such an amount that the phospholipid contained in each 1mL of the resulting suspension of gas-filled microbubbles is 10 to 200ug, for example, 20 to 150ug, for example, 50 to 100 ug), the diameter of the microbubbles is in the range of 0.2 to 10 μm (for example, in the range of 1 to 10 μm), the streptavidin-coupled microbubbles contained in each 1mL of the suspension of gas-filled microbubbles is 0.5 to 200 x 10 ug, for example, streptavidin-coupled microbubbles contained in each 1mL of suspension of gas-filled microbubbles are added in an amount corresponding to 1 to 150 x 10 ug, for example, streptavidin-coupled microbubbles contained in each 1 to 100 x 10 ug, and the amount of the embedding gas in each 1mL of suspension of gas-filled microbubbles is 1 to 200ug (for example, 5 to 150ug, for example, 10 to 100 ug).

The lyophilized formulation according to the third aspect of the present invention, wherein the microbubbles are composed of a material selected from the group consisting of: phospholipid, polyethylene glycol with molecular weight of 2000-6000 and fatty acid.

The lyophilized formulation according to the third aspect of the present invention, wherein the microbubbles are composed of a material selected from the group consisting of: 10 parts of phospholipid, 200-2000 parts of polyethylene glycol with molecular weight of 2000-6000 and 0.2-5 parts of fatty acid.

The lyophilized formulation according to the third aspect of the present invention, wherein the microbubbles are composed of a material selected from the group consisting of: 10 parts of phospholipid, 250-1500 parts of polyethylene glycol with the molecular weight of 2000-6000 and 0.25-2.5 parts of fatty acid.

The lyophilized formulation according to the third aspect of the present invention, wherein the microbubbles are composed of a material selected from the group consisting of: 10 parts of phospholipid, 500-1000 parts of polyethylene glycol with molecular weight of 2000-6000 and 0.5-2 parts of fatty acid.

The lyophilized formulation according to the third aspect of the present invention, wherein the microbubbles are composed of a material selected from the group consisting of: 10 parts of phospholipid, 600-800 parts of polyethylene glycol with molecular weight of 2000-6000 and 0.75-1.5 parts of fatty acid.

The lyophilized formulation according to the third aspect of the present invention, wherein the polyethylene glycol has a molecular weight of 3000 to 5000, for example the polyethylene glycol is polyethylene glycol 4000.

The lyophilized formulation according to the third aspect of the present invention, wherein the aqueous carrier fluid is selected from the group consisting of: water, 0.9% sodium chloride solution, 5% dextrose solution, preferably 0.9% sodium chloride solution.

The lyophilized formulation according to the third aspect of the present invention comprises 10 to 200ug, for example 20 to 150ug, for example 50 to 100ug, of phospholipid per 1ml in an aerated microbubble suspension formed by dissolution with an aqueous carrier liquid.

The lyophilized formulation according to the third aspect of the present invention, wherein the phospholipid is selected from the group consisting of: lecithins such as phosphatidic acid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, cardiolipin and sphingomyelin are exemplified by di-arachidylphospholipid choline (DAPC), di-stearylphospholipid choline (DSPC, 1, 2-Distearoyl-sn-glycero-3-phosphaline), di-palmitoyl phosphatidylglycerol (acid form, DPPG) or sodium salt thereof (DPPG-Na, 1, 2-Dipalmitoyl-sn-glycero-3-phosphate-rac-glycerol sodium (DPPG-Na), di-palmitoyl phosphatidic acid (DPPA).

The lyophilized formulation according to the third aspect of the present invention, wherein the phospholipid is DSPC, DPPG-Na or a combination thereof. For example, DSPC and DPPG-Na are both present in a weight ratio of 1:0.2 to 5.

The lyophilized formulation according to the third aspect of the present invention, wherein streptavidin is coupled to the microbubbles at a weight ratio of phospholipid to streptavidin of 100:0.01 to 0.2, the coupling amount of streptavidin can be changed within a wide range according to the use environment.

The lyophilized formulation according to the third aspect of the present invention, wherein the fatty acid is selected from the group consisting of palmitic acid, stearic acid, oleic acid.

The lyophilized formulation according to the third aspect of the present invention, wherein the weight ratio of the phospholipid sealed in the glass vial for forming microbubbles to the embedding gas in the spatial atmosphere is 10:100 to 5000, for example, the weight ratio of polyethylene glycol to embedding gas is 10:500 to 2500, for example, the weight ratio of polyethylene glycol to embedding gas is 10: 1000-2000.

The lyophilized formulation according to the third aspect of the present invention, wherein the ratio of the sealed space volume within the glass vial to the weight of the entrapped gas in the space atmosphere is 10ml: 20-200 mg, for example, the ratio of the sealed space volume to the weight of the embedding gas in the space atmosphere is 10ml: 25-150 mg, for example, the ratio of the sealed space volume to the weight of the embedding gas in the space atmosphere is 10ml: 25-100 mg.

The lyophilized preparation according to the third aspect of the present invention, wherein a lyophilized lipid in the form of a lyophilized powder composed of polyethylene glycol, phospholipid and fat is conjugated with streptavidin in advance, the lyophilized lipid is present in a sealed glass bottle, and the space atmosphere in the sealed glass bottle is an embedding gas.

A lyophilized formulation according to the third aspect of the present invention, wherein a lyophilized lipid in the form of a lyophilized powder composed of polyethylene glycol, a phospholipid and a fat, which is conjugated with streptavidin in advance, is present in a sealed glass bottle, and the space atmosphere in the sealed glass bottle is an embedding gas; when aqueous carrier fluid is added to the sealed vial, the lyophilized lipids form microbubbles and encapsulate the entrapped gas within the microbubbles, thereby forming gas-filled microbubbles suspended in the aqueous carrier fluid, coupled with streptavidin, and encapsulated with entrapped gas.

The lyophilized preparation according to the third aspect of the present invention has a volume of the aqueous carrier liquid added when the aqueous carrier liquid is added of 20 to 80%, for example, 30 to 70%, for example, 40 to 60% of the bottle content of the glass.

The lyophilized formulation according to the third aspect of the present invention, the vial has a content of 2 to 200ml, such as 2 to 100ml, such as 5 to 50ml, such as 5 to 25ml, such as 10ml.

The lyophilized formulation according to the third aspect of the present invention, which is prepared according to the method according to any one of the embodiments of the fourth aspect of the present invention.

The lyophilized formulation according to the third aspect of the present invention, which is prepared as a liquid formulation of streptavidin-coupled microbubbles for use as a separation reagent in a method of separating target cells from peripheral blood, by: taking the freeze-dried preparation of the streptavidin coupled microbubbles for cell sorting according to any one of the third aspect of the invention, injecting aqueous carrier liquid into a glass bottle through a puncture rubber plug of a syringe, and severely oscillating to dissolve and suspend the content of the glass bottle, thus obtaining the inflated microbubble suspension, namely the liquid preparation of the streptavidin coupled microbubbles.

Further, a fourth aspect of the present invention provides a method for preparing a lyophilized formulation, for example, a lyophilized formulation according to any one of the embodiments of the third aspect of the present invention, (various material additions may be scaled up or down according to the apparatus used in the description of the method of the present invention, the material additions being schematically represented in the description of the present invention, and the production scale may be adjusted accordingly according to the specific production conditions), comprising the steps of:

(i) 1g of phospholipids and the corresponding amount of fatty acid are dissolved in an organic solvent (the amount of organic solvent is usually such that the solute is sufficiently soluble, e.g. 20 to 50 ml) in a flask at room temperature, followed by evaporation of the solvent on a rotary evaporator at 50 to 80℃and then vacuum drying at 30 to 40 ℃;

(ii) Adding 10-50 ml of water into the flask, and oscillating by ultrasonic waves to form suspension;

(iii) Taking the obtained suspension, adding a corresponding amount of polyethylene glycol (for example, adding in the form of 5-20% aqueous solution), uniformly mixing, adding streptavidin, and incubating for 20-45 minutes at room temperature;

(iv) Subpackaging the suspension obtained in the previous step into glass bottles, half-plugging the glass bottles by using a rubber plug for sealing, vacuumizing, freezing, sublimating and drying in a vacuum freeze dryer to remove water, and sealing by pressing plugs to obtain freeze-dried powder;

(v) Filling embedding gas into the sealed glass bottles through the needle puncture rubber plugs (for example, the weight ratio of the filled embedding gas to the phospholipid in each glass bottle space is 50-500:1, for example, 100-250:1, for example, 100-200:1), and filling the embedding gas into the space atmosphere in the glass bottles to obtain the freeze-dried preparation.

In the present invention, the operation of filling the embedding gas into the sealing glass bottle through the needle piercing rubber stopper like the above is performed in the form of liquefied embedding gas. Although filling in gaseous form is also possible, filling of the embedding gas in liquefied form into the glass bottles is preferred from the viewpoint of convenience of industrial operation.

The method according to the fourth aspect of the invention, wherein the embedding gas is added in the form of a liquefied gas of the gas.

The method according to the fourth aspect of the present invention, wherein in step (i) the organic solvent is selected from the group consisting of acetone, hexane, ethanol and combinations thereof, which solvents or solvent mixtures are capable of easily dissolving phospholipids and fatty acids and are easily removed during subsequent rotary evaporation.

The method according to the fourth aspect of the invention, wherein in step (i), the organic solvent is generally used in an amount to a degree that allows sufficient dissolution of the solute, for example 20 to 50ml.

The method according to the fourth aspect of the present invention, wherein in step (iii), the polyethylene glycol is added in the form of a 5 to 15% aqueous solution.

Further, the fifth aspect of the present invention provides the use of the liquid preparation of streptavidin-coupled microbubbles according to any of the second aspect of the invention as a separation reagent in a method for separating target cells from peripheral blood, the method for separating target cells from peripheral blood comprising the steps of:

The use according to the fifth aspect of the invention, wherein the anticoagulant for anticoagulant treatment of peripheral blood is selected from the group consisting of: ethylenediamine tetraacetic acid and its salts such as EDTA-Na2, EDTA-K3, oxalates such as sodium oxalate, heparin and its salts such as heparin sodium, citric acid and its salts such as sodium citrate. The manipulation of anticoagulants to peripheral blood is common knowledge in the art.

The use according to the fifth aspect of the invention, wherein the anticoagulant for anticoagulant treatment of peripheral blood is selected from the group consisting of: EDTA-K2 anticoagulant.

According to a fifth aspect of the invention, the target cell is selected from the group consisting of: t cells such as cd3+ cells, cd4+ cells, cd8+ cells, NK cells such as cd56+ cells, B cells such as cd19+ cells, hematopoietic stem cells such as cd34+ cells.

According to the use of the fifth aspect of the invention, the biotin-labeled cell-specific antibody of interest is selected from the group consisting of: CD3 biotin antibody, CD4 biotin antibody, CD8 biotin antibody, CD56 biotin antibody, CD19 biotin antibody, CD34 biotin antibody.

According to the use of the fifth aspect of the invention, the biotin-labeled cell-specific antibody of interest is selected from the group consisting of: biotin-labeled murine anti-human CD3 antibody, biotin-labeled murine anti-human CD4 antibody, biotin-labeled murine anti-human CD8 antibody, biotin-labeled murine anti-human CD56 antibody, biotin-labeled murine anti-human CD19 antibody, biotin-labeled murine anti-human CD34 antibody. These antibodies can be prepared by methods well known to those skilled in the art, and are also commercially available. In the present invention, biotin-labeled antibodies, particularly those listed above, are used as they are, unless otherwise indicated, all available directly from BD Biosciences.

According to the use of the fifth aspect of the invention, wherein in step (1) 5 to 50ul, e.g. 10 to 40ul, e.g. 10 to 30ul, of antibody is added per 1mL of peripheral blood.

The use according to the fifth aspect of the invention, wherein in step (1), the incubation is at room temperature for 10 to 45min, e.g. at room temperature for 20 to 40min, e.g. at room temperature for 25 to 35min.

According to the use of the fifth aspect of the invention, the streptavidin-coupled microbubbles are embedded gas microbubbles coupled via streptavidin.

The use according to the fifth aspect of the invention, wherein the embedding gas of the embedding gas microbubbles is selected from the group consisting of C3F8, SF6, CF4, freon, N2, CO2, O2, air, in particular from the group consisting of C3F8, SF6, CF4.

According to the use of the fifth aspect of the present invention, wherein in step (2), the streptavidin-coupled microbubbles are entrapped gas microbubbles coupled via streptavidin, and streptavidin-coupled microbubbles corresponding to 0.5 to 20X 10-7 microbubbles are added per 1mL of peripheral blood (the term "0.5 to 20X 10-7 microbubbles" means 7 microbubbles of 0.5 to 20X 10, which are similarly expressed herein), for example streptavidin-coupled microbubbles corresponding to 1 to 15X 10-7 microbubbles, such as streptavidin-coupled microbubbles corresponding to 1 to 10X 10-7 microbubbles.

According to the use of the fifth aspect of the present invention, wherein in step (2), the streptavidin-coupled microbubbles are streptavidin-coupled microbubbles conjugated with an embedding gas, and the streptavidin-coupled microbubbles comprising 1 to 20ug of the embedding gas, for example, the streptavidin-coupled microbubbles comprising 1 to 15ug of the embedding gas, for example, the streptavidin-coupled microbubbles comprising 1 to 10ug of the embedding gas, are added per 1mL of peripheral blood.

The use according to the fifth aspect of the invention, wherein in step (2), the incubation is for 5 to 30min at room temperature, for example for 5 to 25min at room temperature, for example for 10 to 20min at room temperature.

The use according to a fifth aspect of the invention, wherein in step (2), the phosphate buffer is an aqueous solution comprising: 0.8-1.2% w/v human serum albumin, 0.8-1.2 mM EDTA, 0.1-0.15M sodium chloride, 2-3 mM potassium chloride, 7.5-8.0 mM disodium hydrogen phosphate, 0.8-1.2 mM potassium dihydrogen phosphate.

The use according to a fifth aspect of the invention, wherein in step (2), the phosphate buffer is an aqueous solution comprising: 1% w/v human serum albumin, 1mM EDTA, 0.13M sodium chloride, 2.55mM potassium chloride, 7.7mM disodium hydrogen phosphate, 1mM potassium dihydrogen phosphate.

According to the use of the fifth aspect of the invention, the method of isolating target cells from peripheral blood optionally further comprises the steps of:

(6) And freezing the obtained target cell suspension.

Further, the sixth aspect of the present invention provides the use of the lyophilized preparation of streptavidin-coupled microbubbles for cell sorting according to any of the third aspect of the invention as a separation reagent in a method for separating target cells from peripheral blood, the method for separating target cells from peripheral blood comprising the steps of:

(2) Dissolving a freeze-dried preparation of the streptavidin coupled microbubbles with aqueous carrier liquid to obtain a microbubble suspension, adding the streptavidin coupled microbubbles into a test tube, uniformly mixing, incubating, enabling target cells to be further marked by the microbubbles, and adding phosphate buffer for dilution;

The use according to the sixth aspect of the invention, wherein the anticoagulant for anticoagulant treatment of peripheral blood is selected from the group consisting of: ethylenediamine tetraacetic acid and its salts such as EDTA-Na2, EDTA-K3, oxalates such as sodium oxalate, heparin and its salts such as heparin sodium, citric acid and its salts such as sodium citrate. The manipulation of anticoagulants to peripheral blood is common knowledge in the art.

The use according to the sixth aspect of the invention, wherein the anticoagulant for anticoagulant treatment of peripheral blood is selected from the group consisting of: EDTA-K2 anticoagulant.

According to a sixth aspect of the invention, the target cell is selected from: t cells such as cd3+ cells, cd4+ cells, cd8+ cells, NK cells such as cd56+ cells, B cells such as cd19+ cells, hematopoietic stem cells such as cd34+ cells.

According to the use of the sixth aspect of the invention, the biotin-labeled cell-specific antibody of interest is selected from the group consisting of: CD3 biotin antibody, CD4 biotin antibody, CD8 biotin antibody, CD56 biotin antibody, CD19 biotin antibody, CD34 biotin antibody.

According to the use of the sixth aspect of the invention, the biotin-labeled cell-specific antibody of interest is selected from the group consisting of: biotin-labeled murine anti-human CD3 antibody, biotin-labeled murine anti-human CD4 antibody, biotin-labeled murine anti-human CD8 antibody, biotin-labeled murine anti-human CD56 antibody, biotin-labeled murine anti-human CD19 antibody, biotin-labeled murine anti-human CD34 antibody. These antibodies can be prepared by methods well known to those skilled in the art, and are also commercially available. In the present invention, biotin-labeled antibodies, particularly those listed above, are used as they are, unless otherwise indicated, all available directly from BD Biosciences.

According to the use of the sixth aspect of the invention, wherein in step (1) 5 to 50ul, e.g. 10 to 40ul, e.g. 10 to 30ul, of antibody is added per 1mL of peripheral blood.

The use according to the sixth aspect of the invention, wherein in step (1), the incubation is at room temperature for 10 to 45min, e.g. at room temperature for 20 to 40min, e.g. at room temperature for 25 to 35min.

According to the use of the sixth aspect of the invention, the streptavidin-coupled microbubbles are embedded gas microbubbles coupled via streptavidin.

The use according to the sixth aspect of the invention, wherein the embedding gas of the embedding gas microbubbles is selected from the group consisting of C3F8, SF6, CF4, freon, N2, CO2, O2, air, in particular from the group consisting of C3F8, SF6, CF4.

The use according to the sixth aspect of the present invention, wherein in step (2), the streptavidin-coupled microbubbles are entrapped gas microbubbles coupled via streptavidin, and streptavidin-coupled microbubbles corresponding to 0.5 to 20X 10-7 microbubbles are added per 1mL of peripheral blood (the term "0.5 to 20X 10-7 microbubbles" means 7 microbubbles of 0.5 to 20X 10, and similar meaning is used herein in a similar manner), for example streptavidin-coupled microbubbles corresponding to 1 to 15X 10-7 microbubbles, for example streptavidin-coupled microbubbles corresponding to 1 to 10X 10-7 microbubbles.

According to the use of the sixth aspect of the present invention, wherein in step (2), the streptavidin-coupled microbubbles are streptavidin-coupled microbubbles conjugated with an embedding gas, and the streptavidin-coupled microbubbles comprising 1 to 20ug of the embedding gas, for example, the streptavidin-coupled microbubbles comprising 1 to 15ug of the embedding gas, for example, the streptavidin-coupled microbubbles comprising 1 to 10ug of the embedding gas, are added per 1mL of peripheral blood.

The use according to the sixth aspect of the invention, wherein in step (2), the incubation is for 5 to 30min at room temperature, for example for 5 to 25min at room temperature, for example for 10 to 20min at room temperature.

The use according to the sixth aspect of the invention, wherein in step (2), the phosphate buffer is an aqueous solution comprising: 0.8-1.2% w/v human serum albumin, 0.8-1.2 mM EDTA, 0.1-0.15M sodium chloride, 2-3 mM potassium chloride, 7.5-8.0 mM disodium hydrogen phosphate, 0.8-1.2 mM potassium dihydrogen phosphate.

The use according to the sixth aspect of the invention, wherein in step (2), the phosphate buffer is an aqueous solution comprising: 1% w/v human serum albumin, 1mM EDTA, 0.13M sodium chloride, 2.55mM potassium chloride, 7.7mM disodium hydrogen phosphate, 1mM potassium dihydrogen phosphate.

According to the use of the sixth aspect of the invention, the method of isolating target cells from peripheral blood optionally further comprises the steps of:

(6) And freezing the obtained target cell suspension.

Of the various operating steps described above, although specific steps are described herein as being distinguished in some details or language description from those described in the preparation examples of the detailed description section below, those skilled in the art can readily generalize the method steps described above based on the detailed disclosure of the invention as a whole.

Any of the embodiments of any of the aspects of the invention may be combined with any of the other embodiments, provided that they do not contradict. Furthermore, in any of the embodiments of any of the aspects of the present invention, any technical feature may be applied to the technical feature in other embodiments as long as they do not contradict. The present invention is further described below.

All documents cited herein are incorporated by reference in their entirety and are incorporated by reference herein to the extent they are not inconsistent with this invention. Furthermore, various terms and phrases used herein have a common meaning known to those skilled in the art, and even though they are still intended to be described and explained in greater detail herein, the terms and phrases used herein should not be construed to be inconsistent with the ordinary meaning in the sense of the present invention.

Aiming at the defects of the prior art, the invention provides a target cell sorting method which does not depend on conventional methods such as magnetic beads, and the like, and solves the problems of magnetic bead residue, fluorescein introduction caused by flow sorting, and the like. The invention also provides related reagents for the methods. The method is simple and rapid, does not need expensive instruments and equipment, has low cost, has little toxicity to the combined target cells and is not easy to inactivate; the separated cells have high purity and activity and can be used for subsequent experiments, culture and clinical application.

Drawings

FIG. 1 is a schematic flow cytometry schematic of peripheral whole blood before and after sorting CD3 cells by the method of the present invention, wherein it can be seen that the target cells, CD3 cells, are enriched after sorting by the method of the present invention.

Fig. 2 depicts the basic principle of the method of the invention, namely: adding antibodies to a tube to which a mixture of cells (which herein may be whole blood) is added; incubating at room temperature such that the target cells are labeled with a specific antibody; adding the microbubble liquid preparation of the invention, and incubating at room temperature to make target cells marked by microbubbles; followed by centrifugation to separate the target cells, the target cells bound with the specific antibodies and microbubbles float to the liquid surface, and the target cells not sink to the bottom. After centrifugation, the surface of the tube is a layer of microbubbles (usually white), the middle of which is a layer of plasma, and the lower of which is a layer of red blood cells.

Detailed Description

The present invention will be further described by the following examples, however, the scope of the present invention is not limited to the following examples. Those skilled in the art will appreciate that various changes and modifications can be made to the invention without departing from the spirit and scope thereof. The present invention generally and/or specifically describes the materials used in the test as well as the test methods. Although many materials and methods of operation are known in the art for accomplishing the objectives of the present invention, the present invention will be described in as much detail herein.

Example 1 preparation of a lyophilized formulation of streptavidin coupled microbubbles for cell sorting

(i) 1g of phospholipids (DSPC: DPPG-Na=1:1, w/w) and 0.1g of fatty acids (palmitic acid) were dissolved with an organic solvent (hexane/ethanol=4/1, 25 ml) at room temperature in a round bottom flask, followed by evaporation of the solvent on a rotary evaporator at 65℃and then vacuum drying at 35 ℃;

(ii) Adding 30ml of water into the flask, and carrying out ultrasonic vibration to form a suspension;

(iii) Adding polyethylene glycol (PEG 4000, the addition amount of which is 70 times of the weight of the phospholipid and is added in the form of 12% aqueous solution), uniformly mixing, adding streptavidin (phospholipid: streptavidin=100:0.1, w/w), and incubating for 30 minutes at room temperature;

(iv) Subpackaging the suspension obtained in the previous step into glass bottles with the volume of 10ml, wherein the subpackage amount of each bottle is equivalent to 0.4mg of phospholipid, half-plugging the glass bottle by using a rubber plug for sealing, vacuumizing, freezing (-45 to minus 40 ℃), sublimating and drying in a vacuum freeze dryer to remove water, and sealing by pressing plugs to obtain freeze-dried powder;

(v) Filling embedding gas (SF 6, liquefied gas is added) into the sealed glass bottles through the needle puncture rubber plugs, wherein the weight ratio of the filling embedding gas to the phospholipid is 160:1 in the space of each glass bottle, so that the space atmosphere in the glass bottle is filled with the embedding gas, and the freeze-dried preparation is obtained.

Example 2 preparation of a lyophilized formulation of streptavidin coupled microbubbles for cell sorting

(i) 1g of phospholipids (DSPC: DPPG-Na=1:0.2, w/w) and 0.05g of fatty acids (palmitic acid) were dissolved with an organic solvent (acetone/ethanol=3/1, 20 ml) at room temperature in a round-bottomed flask, followed by evaporation of the solvent on a rotary evaporator at 80℃and then vacuum drying at 30 ℃;

(ii) Adding 10ml of water into the flask, and carrying out ultrasonic vibration to form a suspension;

(iii) Taking the obtained suspension, adding polyethylene glycol (PEG 3000, the addition amount of which is 50 times of the weight of the phospholipid and is added in the form of 5% aqueous solution), uniformly mixing, adding streptavidin (phospholipid: streptavidin=100:0.2, w/w), and incubating for 20 minutes at room temperature;

(iv) Subpackaging the suspension obtained in the previous step into glass bottles with the volume of 10ml, wherein the subpackage amount of each bottle is equivalent to 0.5mg of phospholipid, half-plugging the glass bottle by using a rubber plug for sealing, vacuumizing, freezing (-45 to minus 40 ℃), sublimating and drying in a vacuum freeze dryer to remove water, and sealing by pressing plugs to obtain freeze-dried powder;

(v) Filling embedding gas (C3F 8, liquefied gas is added) into the sealed glass bottles through the needle puncture rubber plugs, wherein the weight ratio of the filled embedding gas to the phospholipid is 50:1 in the space of each glass bottle, so that the space atmosphere in the glass bottle is filled with the embedding gas, and the freeze-dried preparation is obtained.

Example 3 preparation of a lyophilized formulation of streptavidin coupled microbubbles for cell sorting

(i) 1g of phospholipids (DSPC: DPPG-Na=1:5, w/w) and 0.2g of fatty acids (stearic acid) were dissolved with an organic solvent (acetone/hexane=1/5, 50 ml) at room temperature in a round bottom flask, followed by evaporation of the solvent on a rotary evaporator at 50℃and then vacuum drying at 40 ℃;

(ii) Adding 50ml of water into the flask, and oscillating by ultrasonic wave to form a suspension;

(iii) Adding polyethylene glycol (PEG 5000, which is added in an amount 100 times the weight of the phospholipid and is added in the form of a 20% aqueous solution) into the obtained suspension, uniformly mixing, adding streptavidin (phospholipid: streptavidin=100:0.01, w/w), and incubating for 45 minutes at room temperature;

(iv) Subpackaging the suspension obtained in the previous step into glass bottles with the volume of 10ml, wherein the subpackage amount of each bottle is equivalent to 0.3mg of phospholipid, half-plugging the glass bottle by using a rubber plug for sealing, vacuumizing, freezing (-45 to minus 40 ℃), sublimating and drying in a vacuum freeze dryer to remove water, and sealing by pressing plugs to obtain freeze-dried powder;

(v) Filling embedding gas (CF 4, liquefied gas is added) into the sealed glass bottles through the needle puncture rubber plugs, wherein the weight ratio of the filled embedding gas to the phospholipid is 100:1 in the space of each glass bottle, so that the space atmosphere in the glass bottle is filled with the embedding gas, and the freeze-dried preparation is obtained.

Example 4 preparation of a lyophilized formulation of streptavidin coupled microbubbles for cell sorting

(i) 1g of phospholipid (DSPC) and 0.075g of fatty acid (oleic acid) were dissolved in an organic solvent (ethanol, 40 ml) at room temperature in a round bottom flask, followed by evaporation of the solvent on a rotary evaporator at 60℃and then vacuum drying at 35 ℃;

(ii) Adding 20ml of water into the flask, and oscillating by ultrasonic wave to form a suspension;

(iii) Taking the obtained suspension, adding polyethylene glycol (PEG 3300, the addition amount of which is 80 times of the weight of the phospholipid and is added in the form of 15% aqueous solution), uniformly mixing, adding streptavidin (phospholipid: streptavidin=100:0.05, w/w), and incubating for 40 minutes at room temperature;

(iv) Subpackaging the suspension obtained in the previous step into glass bottles with the volume of 10ml, wherein the subpackage amount of each bottle is equivalent to 0.6mg of phospholipid, half-plugging the glass bottle by using a rubber plug for sealing, vacuumizing, freezing (-45 to minus 40 ℃), sublimating and drying in a vacuum freeze dryer to remove water, and sealing by pressing plugs to obtain freeze-dried powder;

(v) Filling embedding gas (SF 6, liquefied gas is added) into the sealed glass bottles through the needle puncture rubber plugs, wherein the weight ratio of the filling embedding gas to the phospholipid is 250:1 in the space of each glass bottle, so that the space atmosphere in the glass bottle is filled with the embedding gas, and the freeze-dried preparation is obtained.

Example 5 preparation of a lyophilized formulation of streptavidin coupled microbubbles for cell sorting

(i) 1g of phospholipid (DPPG-Na) and 0.15g of fatty acid (palmitic acid) were dissolved in an organic solvent (hexane 30 ml) at room temperature in a round bottom flask, followed by evaporation of the solvent on a rotary evaporator at 70℃and then vacuum drying at 35 ℃;

(ii) Adding 40ml of water into the flask, and oscillating by ultrasonic wave to form a suspension;

(iii) Taking the obtained suspension, adding polyethylene glycol (PEG 3500, the addition amount is 60 times of the weight of the phospholipid, and the mixture is added in the form of 10% aqueous solution), uniformly mixing, adding streptavidin (phospholipid: streptavidin=100:0.15, w/w), and incubating for 25 minutes at room temperature;

(iv) Subpackaging the suspension obtained in the previous step into glass bottles with the volume of 10ml, wherein the subpackage amount of each bottle is equivalent to 0.35mg of phospholipid, half-plugging the glass bottle by using a rubber plug for sealing, vacuumizing, freezing (-45 to minus 40 ℃), sublimating and drying in a vacuum freeze dryer to remove water, and sealing by pressing plugs to obtain freeze-dried powder;

(v) Filling embedding gas (SF 6, liquefied gas is added) into the sealed glass bottles through the needle puncture rubber plugs, wherein the weight ratio of the filling embedding gas to the phospholipid is 500:1 in the space of each glass bottle, so that the space atmosphere in the glass bottle is filled with the embedding gas, and the freeze-dried preparation is obtained.

Example 6 preparation of a lyophilized formulation of streptavidin coupled microbubbles for cell sorting

According to examples 1 to 5, 5 freeze-dried preparations were prepared by adding glycine (in 5 examples, glycine addition amounts were 6, 8, 4, 2, and 10 times the phospholipid amount) when streptavidin was added, and they were designated as examples 61, 62, 63, 64, and 65, respectively.

Example 11: preparation of liquid formulations of streptavidin-coupled microbubbles for cell sorting

A method of preparing a liquid formulation of streptavidin coupled microbubbles for cell sorting: taking a glass bottle-packed streptavidin coupled microbubble freeze-dried preparation, injecting aqueous carrier liquid into the glass bottle through a puncture rubber plug of an injector, and severely oscillating to dissolve and suspend the content of the glass bottle, thus obtaining an aerated microbubble suspension, namely a liquid preparation of the streptavidin coupled microbubble.

The lyophilized preparation obtained in example 1 was prepared into a suspension of gas-filled microbubbles, i.e., a liquid preparation of streptavidin-coupled microbubbles, according to the proportions shown in the following table, and the diameter of the microbubbles, the concentration of the microbubbles, and the amount of entrapped gas were measured within 5 hours after the preparation of the suspension, and the results are shown in the following table.

* The amount of aqueous carrier liquid added to the lyophilized preparation was such that the resulting gas-filled microvesicle suspension had a weight (μg) of phospholipid per 1 ml.

The microbubble concentration is the measurement result of the prepared gas-filled microbubble suspension by a hemocytometer, and the microbubble diameter is the measurement result of at least 100 microbubble statistics in the read field of view by a microscope, and is the average value obtained by measuring 3 times for each sample.

The amount of entrapped gas in the gas-filled microvesicle suspension was determined using the following method: precisely sucking 20ml of the gas-filled microvesicle suspension, placing the gas-filled microvesicle suspension in a 100ml glass syringe, pumping the plunger of the syringe to the full scale of 100ml so as to fill the syringe with about 80ml of air, sealing the inlet of the syringe connected with the needle by using a cock, precisely weighing the whole syringe (M1), compressing the air in the syringe in the sealed state of the cock (to the position of about 30ml of the syringe scale and difficult to compress again), loosening the plunger, repeating the above operation for 5 times to compress the space in the syringe, opening the cock, pushing the plunger to the position of 20ml (in order to avoid overflowing the microvesicle suspension) so as to discharge the gas in the space atmosphere in the syringe, pumping the plunger of the syringe to the full scale of 100ml so as to replace the space atmosphere in the syringe with air, sealing by using the cock, and precisely weighing the whole syringe (M2), wherein the difference between M1 and M2 is the embedding gas amount in the 20ml gas-filled microvesicle suspension. The results obtained were the average of 3 determinations for each sample, and in the specific determination, a syringe of a suitable size was appropriately selected according to the sensitivity of the balance.

The lyophilized formulations of examples 2-6 were further assayed according to the manner set forth above for example 1, resulting in:

example 2 lyophilized preparation three or two amounts of 0.9% sodium chloride, water, 5% glucose were added respectively to obtain an aerated microbubble suspension, i.e., a liquid preparation of streptavidin-coupled microbubbles, and the diameters of the microbubbles were measured to be in the range of 2.1-8.9 μm, the concentrations of the microbubbles were measured to be in the range of 17-93X 10-A8/mL, and the amounts of entrapped gas were measured to be in the range of 11-142 ug/mL;

example 3 lyophilized preparation three or two amounts of 0.9% sodium chloride, water, 5% glucose were added respectively to obtain an aerated microbubble suspension, i.e., a liquid preparation of streptavidin-coupled microbubbles, and the diameters of the microbubbles were measured to be 1.5-8.3 μm, the concentrations of the microbubbles were measured to be 6-143×10ζ8/mL, and the amounts of entrapped gas were measured to be 7-113 ug/mL;

example 4 lyophilized preparation three or two amounts of 0.9% sodium chloride, water, 5% glucose were added respectively to obtain an aerated microbubble suspension, i.e., a liquid preparation of streptavidin-coupled microbubbles, and the diameters of the microbubbles were measured to be in the range of 2.8-9.5 μm, the concentrations of the microbubbles were measured to be in the range of 13-97×10ζ8/mL, and the amounts of entrapped gas were measured to be in the range of 13-93 ug/mL;

Example 5 lyophilized preparation three or two amounts of 0.9% sodium chloride, water, 5% glucose were added respectively to obtain an aerated microbubble suspension, i.e., a liquid preparation of streptavidin-coupled microbubbles, and the diameters of the microbubbles were measured to be 1.3-8.6 μm, the concentrations of the microbubbles were measured to be 3-136×10≡8/mL, and the amounts of entrapped gas were measured to be 4-86 ug/mL;

example 6 five lyophilized formulations were each separately added with three or two amounts of 0.9% sodium chloride, water, 5% glucose to obtain an aerated microbubble suspension, i.e., a liquid formulation of streptavidin-coupled microbubbles, which were measured to have a microbubble diameter in the range of 1.6-8.3 μm, a microbubble concentration in the range of 8-124 x 10-8/mL, and an embedding gas amount in the range of 9-82 ug/mL.

Three or two amounts of 0.9% sodium chloride, water and 5% glucose were added to each of the above ten lyophilized preparations, and the resulting gas-filled microbubble suspension, i.e., the liquid preparation of streptavidin-coupled microbubbles, was allowed to stand at 4 to 8℃for 48 hours, and the microbubble diameter, the microbubble concentration and the amount of entrapped gas were measured during 48 to 50 hours, as a result:

the diameters of microbubbles are basically unchanged and are all in the range of 1.4-9.6 mu m after three or two amounts of aqueous carrier liquid are respectively added into all ten freeze-dried preparations, the concentration of microbubbles is basically unchanged and is all in the range of 7-142 multiplied by 10 & lt/EN & gt 8 & lt/EN & gt/mL, and after each freeze-dried preparation is prepared into a liquid preparation by a certain amount of certain aqueous carrier liquid, the measured result within 5 hours is basically the same as the measured result after 48 hours, for example, the liquid preparation obtained by adding 75ug of 0.9% sodium chloride into the freeze-dried preparation of the example 1 has the diameters of 5.4 mu m and the concentrations of microbubbles of 53 multiplied by 10 & lt/EN & gt 8 hours;

The percentage of the embedding gas amount after 48 hours after a certain amount of aqueous carrier liquid is used for preparing a liquid preparation for a certain lyophilized preparation is equivalent to the percentage of the embedding gas amount after 5 hours, the percentage is recorded as the residual percentage of the embedding gas after 48 hours, namely, the quotient obtained by dividing the embedding gas amount after 48 hours by the embedding gas amount after 5 hours is multiplied by 100%, the percentage is more stable when the percentage is more than 100%, the embedding gas in the liquid preparation is more stable, the percentage of the embedding gas residual after three or two amounts of aqueous carrier liquid are respectively added in the five lyophilized preparations of example 6 is in the range of 96-102%, for example, the embedding gas residual percentage after 75ug amount of 0.9% sodium chloride is added in the lyophilized preparation of example 61 is 98.7%, the residual percentage after three or two amounts of aqueous carrier liquid are respectively lyophilized in the range of 63-72%, for example 1-5, and the embedding gas residual percentage after 75ug amount of 0.9% sodium chloride is added in the lyophilized preparation of example 1-5 is 66.4%.

Although in practice the lyophilized formulation may be ready for use as a liquid formulation of an aerated microvesicle suspension, i.e. streptavidin coupled microvesicles, for cell sorting of interest, i.e. the five lyophilized formulations of examples 1-5 may meet the relevant cell sorting operation requirements, the lyophilized formulation of example 6 is more preferred as it enables a more general applicability of the cell sorting method. The lyophilized formulation of example 6 differs from the lyophilized formulations of examples 1-5 only in that glycine is supplemented, and the above results found are not anticipated at all by the prior art. Thus, in any embodiment of any aspect of the invention, e.g. the liquid formulation of the second aspect of the invention or the lyophilized formulation of the third aspect of the invention, the material comprising the microbubbles further comprises glycine, wherein the amount of glycine added is 2 to 10 times the amount of phospholipids; in any embodiment of any aspect of the present invention, for example in the step of preparing a lyophilized formulation according to the fourth aspect of the present invention, glycine is further added in an amount of 2 to 10 times the amount of phospholipid when streptavidin is added.

Example 21: isolation of CD3+ cells from Whole blood Using streptavidin-conjugated microbubbles (1 mL of Whole blood is taken as an example)

1. Reagent:

biotin-labeled murine anti-human CD3 antibodies were purchased from BD Biosciences;

streptavidin coupled microvesicle lyophilized formulations and liquid formulations: the lyophilized preparation obtained in example 1, which was prepared by adding 0.9% sodium chloride (addition amount 75 ug) by the method of example 11 of the present invention to prepare a liquid preparation, was used within 5 hours;

test tube spin mixers are available from Thermo mixer company;

desk top microcentrifuge was purchased from Thermo filter company;

20% human serum albumin was purchased from Shandong Thai Bioproduct Co., ltd;

EDTA was purchased from Gibco;

phosphate buffer an aqueous solution was prepared according to the following formulation: 1% w/v human serum albumin, 1mM EDTA, 0.13M sodium chloride, 2.55mM potassium chloride, 7.7mM disodium hydrogen phosphate, 1mM potassium dihydrogen phosphate.

2. Test procedure:

(1) Placing 1mL of peripheral blood subjected to anticoagulation treatment in advance with an anticoagulant (EDTA-K2 in this example) into a 2mL EP test tube, adding a target cell specific antibody (CD 3-biotin antibody 20 ul) marked by biotin, uniformly mixing, placing the test tube on a test tube rotary mixer, and incubating at room temperature for 30 minutes to mark target cells with the specific antibody;

(2) Then adding a liquid preparation (120 ul) of the streptavidin coupled microbubbles into the test tube, uniformly mixing, placing the mixture on a test tube mixer, incubating at room temperature (20 minutes) to further mark target cells by the microbubbles, and adding 0.5mL of phosphate buffer for dilution;

(3) Centrifuging the tube (500 g in a bench-top microcentrifuge, for 10 minutes) to separate the target cells, the target cells combined with the specific antibodies and microbubbles floating on the upper liquid layer (i.e., cd3+ cell layer) and the non-target cells sinking on the lower part;

(4) Sucking the upper layer liquid containing the target cells to obtain the target cells, wherein the specific operation is as follows:

(41) Taking a 2mL EP tube, marking as a positive sample, carefully sucking out the separated upper layer sample by using a 200ul pipette, and transferring the upper layer sample into the positive sample EP tube to obtain target cells; the remaining blood sample is a negative sample;

(42) Another EP tube, labeled "unseparated sample", was taken and 500uL of anticoagulated whole blood was added thereto.

3. The following operations for methodology evaluation may also be continued:

(5) Accurately weighing the mass of a positive sample and the mass of a negative sample, and calculating the volume of each sample according to 1g approximately equal to 1 mL;

(6) Pressurized lysis of microbubbles: another 10mL syringe is taken, the cell suspension in the positive sample is sucked into the syringe, and the air is continuously pumped by about 10 mL. Taking down the needle head, and screwing the needle head part of the syringe by using a luer needle cap; holding the syringe, forcibly pressing down the piston to the volume of about 1mL in the syringe, and uniformly mixing the cell suspension sample after 30 seconds of holding; the embedding gas can completely escape from the microbubbles by repeating the steps for 2 to 3 times; after observing that the cell suspension in the syringe is clear and transparent, the sample is returned to the "positive sample" EP tube for subsequent detection or application.

4. Detecting recovery rate, cell purity and activity of separated sample by flow cytometry

Instrument reagent: flow cytometry was purchased from BD company, usa, model CANTOII; the hemocytometer was purchased from Hizimeric, japan, model XN-350; the data analysis software is flow cytometer self-contained software FACSDiva; CD3-FITC antibodies were purchased from BD Biosciences; CD45-PE antibodies were purchased from BD biosciences; erythrocyte lysate ACK lysis buffer from Gibco.

The detection method comprises the following steps:

(a) Counting five kinds of white blood cells of the separated positive sample, negative sample and unseparated sample by using a hemocytometer, and calculating the contents of white blood cells WBC, red blood cells RBC and the like in the sample;

(b) Taking three BD flow pipes, and correspondingly marking 'pre test', 'positive test', 'negative test';

(c) 2ul of CD3-FITC, 2ul of CD45-PE (mouse anti-human CD45 antibody), 2ul of 7-AAD reagent (7-AAD antibody) are added to each of the three test tubes;

(d) Taking 100ul suspensions in a positive sample, a negative sample and an unseparated sample, respectively adding the suspensions into a corresponding flow tube, carrying out vortex mixing for 2 seconds, and then placing the mixture in a refrigerator at 4 ℃ for incubation for 30 minutes;

(e) Adding 1mL of ACK erythrocyte lysate into the well-incubated flow tube, vortex mixing for 2 seconds, and then placing the mixture in a refrigerator at 4 ℃ for incubation for 15 minutes;

(f) The proportion of CD3 positive cells was detected using a flow cytometer, and recovery, purity, and viability of CD3 positive cells was calculated using BD FACSDiva software. Specifically, each sample tube is put on a machine for flow cytometry detection, SSC-FSC is used for gating, lymphocyte group P1 is selected by circle, CD45 positive cell group is used for gating P2, 7-AAD negative cell group is selected by circle in P2, P3 is selected by circle in cross, CD45 and CD3 double positive cell group Q2 are selected by circle in P3, and the recovery rate of CD3+ T cells is calculated;

(g) The recovery rate calculation formula:

a typical schematic flow cytometry image of peripheral whole blood before and after CD3 cells are sorted by the above method is shown in FIG. 1, from which it can be seen that the target cells, namely CD3 cells, are enriched after sorting by the above method.

5. Test results

Peripheral Blood (PB, also commonly referred to as whole Blood) was obtained from 4 different Blood donors, from which CD3 positive T-cells were isolated as described above.

Results: the whole blood units (n=4) were separated into two independent subjects, and they separated cd3+ positive cells on a 1-mL and 5-mL scale using the above-described method of the present invention and MACS method (i.e., the magnetic bead sorting method, see [0030] - [0044] described in the specification of CN101845417 a), respectively. When using the method of the invention, recovery of cd3+ cells was obtained at an average of 79.3% (±7.6%), viability at an average of 92.6% (±8.2%), and cell purity at an average of 95.3% (±3.5%); when MACS method was used, recovery of cd3+ cells was obtained at an average of 61.3% (±8.6%), viability at an average of 90.2% (±7.6%) and cell purity at an average of 93.2% (±6.7%) indicating that the inventive method was comparable to MACS method in cell viability and cell purity, but the inventive method was significantly higher in recovery.

The method provided herein is used for separating CD3+ cells, can efficiently separate CD3+ T-cells directly from peripheral blood, i.e., whole blood, and has a purity of up to 90% or more, and has excellent recovery (up to 70% or more) and excellent cell viability (up to 85% or more).

The whole process of the method can be completed within 2 hours, generally within 1 hour, and has significantly higher separation efficiency than the prior art method. In particular, in the MACS method (i.e., magnetic bead sorting method), CD3 is generally used ⁺ The connection of the beads is directly operated according to the instructions of the suppliers, and usually takes more than a few hours; in the method of the present invention, however, the process is from peripheral blood to purified CD3 ⁺ T-cell isolation can be accomplished within an hour.

Example 22: isolation of CD3+ cells from Whole blood Using streptavidin-coupled microbubbles

Referring to the method of example 21 herein, except that the streptavidin-coupled microvesicle lyophilized formulation and liquid formulation were modified as follows: the lyophilized preparation obtained in example 61, which was prepared by adding 0.9% sodium chloride (75 ug added) by the method of example 11 of the present invention to prepare a liquid preparation, was used during 45-48 hours at 4-8℃to verify the reliability of the liquid preparation of the present invention after properly changing the conditions on the one hand, and the usability of the liquid preparation of the present invention after a certain period of storage on the other hand.

Results: CD3 ⁺ The recovery of cells was 80.5% (±4.8%), the viability was 93.4% (±5.6%) and the purity of cells was 97.1% (±5.2%) on average. The results show that the liquid preparation of the present invention has excellent separation effect even if glycine is added, and it has excellent functions after being stored for a certain period of time.

Example 23: isolation of CD4+ cells from Whole blood Using streptavidin-coupled microbubbles

Referring to the method of example 22 herein, except that instead of sorted target cells being CD4+ cells, the formulated streptavidin-conjugated microvesicle liquid formulation is used within 1-4 hours after formulation and the relevant reagents used in the assay are adapted, e.g. biotin-labeled murine anti-human CD4 antibodies that need to be used are likewise available commercially and in particular from BD Biosciences. The method of the embodiment can verify the usability of the method, the material and the like aiming at other target cells.

Results: CD4 ⁺ The recovery of cells was average 82.2% (±6.1%), viability was average 91.4% (±7.4%) and cell purity was average 96.2% (±3.8%). The results indicate that the methods, materials, etc. of the present invention are still effective against other target cells.

Example 24: isolation of other target cells from Whole blood Using streptavidin-coupled microbubbles

Referring to the method of example 23 herein, except that the target cells to be sorted were four cells, cd8+ cells, cd56+ cells, cd19+ cells, cd34+ cells, respectively, the formulated streptavidin-coupled microvesicle liquid formulation was used within 1 to 4 hours after formulation, and the relevant reagents used in the assay were adapted, e.g., biotin-labeled murine anti-human CD8 antibodies that were used as required were likewise available commercially, and in particular were purchased from BD Biosciences. The method of the embodiment can verify the usability of the method, the material and the like aiming at other target cells.

Results: CD8 ⁺ Cell recovery averages 80.4% (±6.7%), viability averages 94.2% (±7.4%), cell purity averages 95.7% (±5.4%), CD56 ⁺ Cell recovery averages 76.2% (±4.5%), viability averages 90.5% (±7.4%), cell purity averages 96.6% (±7.4%), CD19 ⁺ Cell recovery averages 79.4% (±5.8%), viability averages 92.1% (±7.4%), cell purity averages 97.3% (±5.6%), CD34 ⁺ The recovery of cells was on average 81.7% (±3.6%), viability was on average 93.5% (±7.4%) and cell purity was on average 95.6% (±7.3%). The results indicate that the methods, materials, etc. of the present invention are still effective against other target cells.

Example 25: isolation of CD3+ cells from Whole blood Using streptavidin-coupled microbubbles

Referring to the method of example 22 herein, except that the streptavidin-coupled microvesicle lyophilized formulation and liquid formulation were modified as follows: the lyophilized formulations obtained in examples 62, 63, 64 and 65 were prepared by adding water (100 ug) by the method of example 11 according to the present invention to prepare liquid formulations, and then allowed to stand at 4 to 8℃for 45 to 48 hours.

Results: four lyophilized formulations were directed against CD3 ⁺ The average recovery rate of the cells is 79.5-83.1%, the average viability is 94.2-95.7%, and the average cell purity is 95.5-97.4%. The results show that the freeze-dried preparation and the liquid preparation have excellent cell separation effect.

In particular, the invention provides a target cell sorting method which is independent of conventional methods such as magnetic beads and the like, aiming at the defects of the prior art, and solves the problems of residue of the magnetic beads, defects of fluorescein introduced in flow sorting and the like. The method is simple and rapid, does not need expensive instruments and equipment, has low cost, has little toxicity to the combined target cells and is not easy to inactivate; the separated cells have high purity and activity and can be used for subsequent experiments, culture and clinical application.

The examples of the present invention should be understood as merely illustrative of the present invention and not as limiting the scope of the present invention. Various changes and modifications to the present invention may be made by one skilled in the art after reading the description herein, and such equivalent changes and modifications are intended to fall within the scope of the present invention as defined in the appended claims.

Claims

1. The streptavidin coupled microbubble liquid preparation for cell sorting is one kind of inflated microbubble suspension in water carrier liquid, and the microbubbles are coupled with streptavidin and have diameter of 0.2-10 microns, and each 1mL of inflated microbubble suspension contains 0.5-200 x 10-8 microbubbles of streptavidin coupled microbubbles and each 1mL of inflated microbubble suspension has embedding gas in 1-200 ug; the embedding gas is selected from C3F8, SF6 and CF4, and the microbubbles are composed of the following materials in proportion: 10 parts of phospholipid, 500-1000 parts of polyethylene glycol with molecular weight of 3000-5000, 0.5-2 parts of fatty acid and glycine, wherein the added amount of glycine is 2-10 times of the amount of phospholipid, the phospholipid is selected from DSPC, DPPG-Na or a combination thereof, the fatty acid is selected from palmitic acid, stearic acid and oleic acid, and the aqueous carrier fluid is selected from: the preparation method comprises the steps of water, 0.9% sodium chloride solution and 5% glucose solution, wherein each 1ml of the solution contains 10-200 ug of phospholipid, streptavidin is coupled on the microbubbles, and the weight ratio of the phospholipid to the streptavidin is 100:0.01 to 0.2.

2. The liquid formulation according to claim 1, wherein the microbubbles have a diameter in the range of 1-10 μm.

3. The liquid formulation according to claim 1, comprising 1 to 150 x 10≡8 microbubbles of streptavidin coupled microbubbles per 1mL of the gas-filled microbubble suspension.

4. The liquid formulation according to claim 1, comprising 1 to 100 x 10≡8 microbubbles of streptavidin coupled microbubbles per 1mL of the gas-filled microbubble suspension.

5. The liquid preparation according to claim 1, wherein the amount of the embedding gas in the microbubbles per 1mL of the gas-filled microbubble suspension is 5 to 150ug.

6. The liquid preparation according to claim 1, wherein the amount of the embedding gas in the microbubbles per 1mL of the gas-filled microbubble suspension is 10 to 100ug.

7. The liquid formulation according to claim 1, said microbubbles being composed of materials in the following proportions: 10 parts of phospholipid, 600-800 parts of polyethylene glycol with molecular weight of 2000-6000, 0.75-1.5 parts of fatty acid and glycine, wherein the adding amount of glycine is 2-10 times of the amount of the phospholipid.

8. The liquid preparation according to claim 1, wherein the phospholipid content per 1ml is 50 to 100ug.

9. The liquid formulation according to claim 1, wherein the phospholipid is both DSPC and DPPG-Na in a weight ratio of 1:0.2 to 5.

10. The liquid formulation of any one of claims 1-9, which is prepared by: taking a freeze-dried preparation of streptavidin coupled microbubbles for cell sorting, injecting aqueous carrier liquid into a glass bottle through a puncture rubber plug of an injector, and severely oscillating to dissolve and suspend the content of the glass bottle, thus obtaining an aerated microbubble suspension, namely a liquid preparation of streptavidin coupled microbubbles; the freeze-dried preparation is prepared according to the method comprising the following steps:

(i) Dissolving 1g of phospholipid and a corresponding amount of fatty acid in 20-50 ml of organic solvent at room temperature in a flask, then evaporating the solvent on a rotary evaporator at 50-80 ℃, and then drying in vacuum at 30-40 ℃;

(ii) Adding 10-50 ml of water into the flask, and carrying out ultrasonic oscillation to form a suspension;

(iii) Adding a corresponding amount of polyethylene glycol into the obtained suspension, adding the mixture in the form of a 5-20% aqueous solution, uniformly mixing, adding streptavidin and glycine, and incubating for 20-45 minutes at room temperature;

(v) Filling embedding gas into the sealed glass bottles through the needle puncture rubber plugs, wherein the weight ratio of the filled embedding gas to the phospholipid is 50-500 in each glass bottle space: 1, filling embedding gas into the space atmosphere in the glass bottle to obtain the freeze-dried preparation.

11. Use of a liquid formulation of streptavidin-coupled microbubbles according to any of claims 1-10 as a separation reagent in a method for separating target cells from peripheral blood, comprising the steps of: