67 results about "Magnetosome" patented technology

Methods and compositions for using magnetosomes as cellular contrast agents and markers for magnetic resonance imaging are provided. Certain methods involve synthesizing magnetosomes in a cell as directed by a nucleotide construct comprising an exogenous polynucleotide sequence, wherein the magnetosome serves as a contrast agent or marker for magnetic resonance imaging. Methods of synthesizing and isolating magnetosomes for introduction into immune-matched cells within a tissue or subject for use as a contrast agent or marker for magnetic resonance imaging are also provided. Also provided are methods for stably transfecting cells to express a polypeptide that drives or modulates magnetosome production in the cell, cells produced by such methods and methods for their isolation, transgenic animals comprising at least one eukaryotic cell produced by such methods, and vectors and delivery systems for the transfection of such cells. Further provided are methods for non-invasively generating a visible image of a tissue or subject containing at least one cell such transfected cell, as well as use of such methods to monitor the location, migration, or proliferation of cells in a tissue or subject or to detect or monitor gene expression in a tissue or subject.

The invention relates to a biological nanometer magnetic target anti-cancer drug, which is formed by coupled biological nanometer magnetic smalls and anti-cancer chemical drug. Wherein, the biological nanometer magnetic small is nanometer magnetic particle formed in magnetic bacterial cell, at 35-120nm diameter, while its main component is Fe3O4 or Fe3S4; single magnetic particle is packed by film; and the coupled anti-cancer chemical drug comprises chemotherapy drug, nucleic acid drug, radioactive nuclide or antibody drug. The invention also provides relative production that using physical adsorption couple or based on the active function group contained by smalls and anti-cancer drug, to select right coupler via chemical reaction to couple them. And the smalls has better bioavailability, less side effect, therefore, the anti-cancer drug can be accurately transmitted to ill part via external magnetic field, to reduce the contact between drug and normal organism., to realize target positioning treatment.

The invention provides a method for producing magnetosome by cultivating magnetic bacteria, which takes air as an oxygen supplying way and maintains the continuous growth of the magnetic bacteria with a material feeding way, and when dissolved oxygen reaches or gets lower than the dissolved oxygen suitable for magnetosome production, the dissolved oxygen is controlled at a proper dissolved oxygen range that is suitable for magnetosome production through agitating rotation speed, air flow speed and the dissolved oxygen in cascade. The magnetic bacteria cultivating method does not need air distribution and pure inert gases, but uses air aeration for oxygen supply, thus lowering initial dissolved oxygen from the saturation state of 100 percent to 0 percent, and the coordinated adjustment of agitating rotation speed and air flow speed can control the dissolved oxygen to be any value between the saturation states of 0 percent and 20 percent, thus lowering the production cost of magnetosome and providing technical guarantee for researching the physiological and biochemical characteristics of the magnetic bacteria under different dissolved oxygen levels.

The invention provides a method for culturing magnetotactic bacterium high-yield magnetic particles chemostatically with high density; magnetotactic bacterium is cultured through a submerged fermentation culture method; the fermentation culture medium contains a carbon source, a nitrogen source and an iron source; dissolved oxygen is controlled in the fermentation process by stages, and materials are supplemented by regulating the pH value. The method realizes the chemostatical high-density culture of the magnetotactic bacterium and the mass production of the magnetic particles; the density of the cells cultured for 36h to 48h is 12OD565nm, the dry weight of the magnetic particles is 80mg/L to 100mg/L, and the fermentation cycle is shortened. The method lays solid foundation for the industrialized production of bacterium magnetic particles.

The invention provides a preparation method for a Fe2S4 nanocrystalline material. The method comprises the following steps of: mixing an iron source compound and beta-cyclodextrin in ethylene glycol, and heating to obtain turbid liquid; and mixing the obtained turbid liquid and a sulphur source compound and reacting to obtain the Fe3S4 nanocrystalline material. According to the method, the Fe3S4 nanocrystalline material which is prepared by using the ethylene glycol as a solvent and the beta-cyclodextrin as surfactant is high in crystallinity, stability, water solubility and biocompatibility. By the wrapping of the beta-cyclodextrin, the surface of the Fe3S4 nanocrystalline material is provided with a very thin protection film, so that the nanocrystalline material is similar to biological magnetosome in nature, has the function which is similar to that of the biological magnetosome, and can be used in the fields of magnetic resonance imaging, medicine carrying and other biological medicines.

The invention relates to a medicine slow-release nanoparticle wrapping magnetosomes of magnetotactic bacteria and a preparation method of the medicine slow-release nanoparticle. The medicine slow-release nanoparticle comprises the magnetosomes of magnetotactic bacteria, chitosan, pharmaceutic adjuvant and medicine components. The preparation method includes the steps of collecting the magnetosomes of magnetotactic bacteria, mixing the materials, conducting spray drying to obtain the nanoparticle, wherein the grain size of the nanoparticle ranges from 100 nanometers to 50 micrometers. According to different treatment aims, the nanoparticle can serve as an oral slow-release formulation, can be used as a slow-release formulation for preparing targeted medicine as well, and can be widely applied to the field of biological medicine.

The invention provides a method for purifying a bacterial magnetosome at a large scale, which comprises the following steps: breaking magnetotactic bacterial cells by a high-pressure homogenizer, separating and cleaning the magnetosome by a magnetic chromatography system, digesting membrane protein with protease k, electroeluting, desalting by a magnetic stirring system, etc. The method has the advantages of continuous operations, and that the purification period is shortened from 2-3 months to less than one week, damage caused by ultrasonication to the plasma membrane of the magnetosome is effectively reduced, the membrane protein on the surface of the magnetosome is reduced and the immunogenicity of the purified magnetosome is lowered.

The invention relates the segregator, comprising permanent magnet components, cover (3), separating cap (4) and sample cap (5). In the separating cap (4) there is inner edge (6) which is connected with inner wall of separating cap (4); under interior extent (6) there is rubber ring (7), and between them there is filter paper; permanent magnet components comprises N magnet and S magnet; separating cap (4) is connected with sample cap (5). The invention solves the problem that the magnetic bacteria is not easy to separate, and the invention has the advantages of simple technology, low cost, easy usage and strong practicality.

The invention provides an optimal dissolved oxygen controlling method for producing magnetosome through magnetic bacteria cultivation, under the precondition ensuring that cell growth is not limited by nutrition, the method takes the speed slowing of cell growth as a signal that dissolved oxygen reaches and gets lower than the critical dissolved oxygen of cell growth, and the method controls rotation speed and aeration flow speed so as to maintain the dissolved oxygen constantly at the critical dissolved oxygen of cell growth, which is the optimal dissolved oxygen level that is suitable for both cell growth and magnetosome synthesis. Experiments prove that by adopting the optimal dissolved oxygen controlling method for producing magnetosome through magnetic bacteria cultivation, not only the final cell cultivation level and the magnetosome yield, but also the cell growth speed and the magnetosome throughput rate achieve the highest level in existing reports.

The invention provides a water-soluble fluorescent magnetosome and its preparation method. The water-soluble fluorescent magnetosome contains the following ingredients: magnetosome and cysteine. In addition, cysteine modifies the surface of magnetosome. According to the invention, a cysteine-modified fluorescent magnetosome is prepared by a biomineralization-surface modification method. The fluorescent magnetosome is water-soluble and has good fluorescent stability and high fluorescence intensity. Meanwhile, the preparation method is simple and easy to operate, and no toxic substance participates in the preparation. According to the invention, application of the fluorescent magnetosome in magnetic targeting and fluorescence trace is greatly enhanced.

The invention discloses a bacterial magnetic particle (BMP)-agglutinin complex and a preparation method and application thereof, belonging to the technical field of separation and purification. The preparation method comprises the following steps: performing surface modification and transformation on BMPs, and adding a cross-linking agent and agglutinin for coupling, thereby obtaining the BMP-agglutinin complex. The surfaces of the BMPs are modified, the influence of self-proteins of the BMPs on subsequent application is eliminated, more primary amino is provided for agglutinin coupling due to the addition of PE, the coupling efficiency is improved, and the dispersity of the BMPs is improved; the cross-linking agent (BS3) serves as a connecting arm, so that covalent coupling is realized between the BMPs and the agglutinin, and an agglutinin recognition sugar chain area is not damaged; and moreover, the concentration of a buffer solution is regulated, the preparation time is shortened, and the coupling efficiency is improved. The complex disclosed by the invention is used for enriching and separating specific glycoproteins, and compared with traditional affinity chromatography, the method disclosed by the invention has the advantages of fewer steps, short time and the like.

The invention relates to a composite tumor gene vaccine taking a bacterial nano magnetosome as a carrier and a preparation method thereof. The range of a pH value of the optimal phosphate buffer system when the bacterial nano magnetosome is connected with the gene vaccine and magnetic field intensity and magnetic field acting time used by in-vitro transfection and in-vivo immunization are provided specifically, and treatment dosage range and immunization way are determined when the composite gene vaccine is used for treating a tumor model. A novel simple and convenient gene delivery mode is established, and a preparation condition and an immunization method of a new gene vaccine are provided for gene treatment.

The invention relates to a way of determining the drug loading of the bacteria nanometer magnetosome, which uses an ultraviolet spectrum or a fluorescence spectrum to determine the biggest ultraviolet absorbing wavelength or biggest emission wavelength Gamma max of the tested drug. The ultraviolet absorbance values or the fluorescence transmission intensity values of the drug solution with different concentrations are tested at the Gamma max to draw the standard working curves. The drug with known concentration mixed-react with the bacteria nanometer magnetosome, and the magnetosome after reaction is separated to acquire the supernatant; and the drug solution with the same concentration and quantity with the former solution is prepared without reacting with the bacteria nanometer magnetosome to be as the comparison solution of the blank reaction; the ultraviolet absorbance value or the fluorescence transmission intensity value of the supernatant and the comparison solution of the blank reaction at the Gamma max are respectively determined, and the drug loading of the bacteria nanometer magnetosome is calculated by the standard working curves according to the difference of the two.

The invention discloses a bacterial nano magnetic corpuscle-glycosphingolipid compound and a preparation method and an application of the compound, and belongs to the fields of separation and medicines. The BMPs-glycosphingolipid compound disclosed by the invention is prepared by the following steps: firstly, removing surface proteins of BMPs by using a surfactant; suspending the BMPs into a glycosphingolipid solution; and carrying out ultrasonic or room-temperature reaction, and incubating to couple the BMPs to the glycosphingolipid, thereby obtaining the bacterial nano magnetic corpuscle-glycosphingolipid compound. Irrelevant protein is effectively prevented from being introduced by removal of the surface proteins, and the protein acting with the glycosphingolipid can be obtained. The compound disclosed by the invention can be used for promoting utilization of the glycosphingolipid by cells, meanwhile, magnetic particles in the compound can play a targeting effect, and the compound is guided to be gathered towards the focus part, so that the drug targeting property is relatively high. After the compound is introduced into the tumor region, magnetic targeting thermal therapy can also be introduced, thereby further treating the focus.

In this disclosure, we describe a method for the treatment of tumor(s) or tumor cell(s) or cancer(s) in a subject in need by the generation of heat. The latter is produced by chains of magnetosomes extracted from whole magnetotactic bacteria and subjected to an alternative magnetic field. These chains of magnetosomes yield efficient antitumoral activity whereas magnetosomes unbound from the chains or kept within the whole bacteria produce poor or no antitumoral activity. The introduction of various chemicals such as chelating agents and/or transition metals within the growth medium of the bacteria improves the heating properties of the chains of magnetosomes. Moreover, the insertion of the chains of magnetosomes within a lipid vesicle is also suggested in order to favor their rotation in vivo and hence to improve their heating capacity. The vesicle can contain an antitumoral agent together with the chains of magnetosomes. In this case, the agent is released within the tumors by heating the vesicle.

The invention discloses a culture method of magnetotactic bacteria AMB-1. The culture method comprises the following steps that 1, activating bacteria; 2, obtaining first enlarged culture bacteria; 3, obtaining second enlarged culture bacteria; 4, obtaining third enlarged culture bacteria; 5, taking a proper amount of the third enlarged culture bacteria liquid obtained in the step 4 to be inoculated into a sterile fluid nutrient medium 1653 MSMG, and conducting fermenter culture; 6, conducting centrifugation to collect the bacteria in the materials obtained in the step 5, and conducting ultrasonication washing, purification and freeze drying to obtain magnetosomes. According to the method, the aim that the AMB-1 bacteria density and the magnetosome yield are greatly improved though fermenter culture can be achieved under the conditions that only the addition amount of an iron source is changed and pH is controlled to be constant.

The invention provides a novel method for enriching and detecting biomedical and environmental specimens by using magnetic particles. The method mainly comprises the following steps: preparing immunomagnetic beads; to be specific, coupling magnetosome with SPA by using a coupling method to prepare immunomagnetic beads; connecting the immunomagnetic beads with corresponding antibodies; to be specific, combining the Bdomain of the SPA with FC ends of non-variable regions of antibodies to prepare the immunomagnetic beads combined with the antibodies; and carrying out enrichment; to be specific, mixing biomedical and environmental specimens with the magnetic beads connected with corresponding antibodies, and enriching antigens corresponding to the antibodies. The method provided by the invention has a good enrichment effect on antigens in biomedical and environmental specimens, and is superior to synthetic magnetic beads.

An acoustic wave medical treatment of a body part of an individual in which nanoparticles are administered to the body part of the individual and the acoustic wave is applied on the body part. The acoustic wave is sequentially applied on the body part, and/or the nanoparticles are magnetosomes. Also, compositions that include these nanoparticles.

The invention relates to a method for culturing magnetosome-producing iron oxidizing bacteria, comprising the following steps: inoculating the magnetosome-producing iron oxidizing bacteria into a culture medium, fermenting and culturing, wherein the culture temperature is 20 DEG C and the fermentation temperature is 20 DEG C; 25 DEG C. In addition to the culture temperature, the invention furtherconsiders the influence of the composition of the culture medium, the oxygen flux and other parameters on the production of ferrooxidizing bacteria magnetosomes, and finally realizes the purpose of significantly increasing the production rate of magnetosomes.

The invention discloses a double cross-linking agent AMB-1 magnetosome drug carrier, and a preparation method and application thereof. The double cross-linking agent AMB-1 magnetosome drug carrier employs an AMB-1 magnetosome possessing a natural lipid double-molecular-membrane layer as a carrier, employs genipin and poly(L-glutamic acid) as a double-molecule cross-linking material, so that the double cross-linking agent AMB-1 magnetosome drug carrier is formed, and is capable of carrying a single medicine or multiple medicines and helps to construct a targeting drug system. A natural double cross-linking agent is employed, the toxicity is low and the biocompatibility is good, the prepared double cross-linking agent AMB-1 magnetosome drug carrier is improved in drug loading and entrapment rate compared with a conventional technology, efficient loading of a single or multiple medicines is realized, burst release effect does not exist, the release period is long, the medicine self efficacy is not influenced, the effects of medicine combined usage and synergic interaction are realized while targetable drug delivery is realized, and also the preparation technology is simple, convenient to operate, green and environment-friendly, and possesses wide application prospect.

The invention provides a supercritical carbon dioxide method for extraction separation of magnetosomes from magnetotactic bacteria. The method mainly includes the processes of organic solvent pretreatment, supercritical carbon dioxide extraction separation, organic solvent and water soluble residue removal. By using the method, magnetosomes can be extracted and separated from magnetotactic bacteria under optimal supercritical carbon dioxide fluid temperature, pressure conditions and extraction times. The magnetosomes obtained by extraction separation have the characteristics of small particle size, good monodispersity, high stability, no organic solvent residue, high saturation magnetization intensity, and high extraction separation efficiency, etc.

The invention provides a target protein-intein-magnetosome fusion protein, an intelligent bacterium constructed by using the target protein-intein-magnetosome fusion protein and used for automatically purifying a product and a preparation method of the intelligent bacterial expression system, and the fusion protein is formed by directly connecting a target protein, intein and magnetosome membrane protein in series or operably connecting the target protein, the intein and the magnetosome membrane protein through a flexible Linker; the invention also provides a target protein-intein-magnetosome fusion gene. The fusion gene comprises an upstream sequence of a magnetosome membrane protein gene, a nano antibody gene, an intein gene, the magnetosome membrane protein gene and a downstream sequence of the magnetosome membrane protein gene; and the invention also provides an intelligent bacterium constructed by using the target protein-intein-magnetosome fusion gene and capable of automatically purifying a product . Compared with a traditional prokaryote expression system, the intelligent bacterium has the advantages of being mild in target protein purification condition, free of additional reagents, low in cost, easy to operate, high in purity and small in influence on the yield and the like of the target protein.