33 results about "Bacterial outer membrane vesicles" patented technology

Existing methods of meningococcal OMV preparation involve the use of detergent during disruption of the bacterial membrane. According to the invention, membrane disruption is performed substantially in the absence of detergent. The resulting OMVs which retain important bacterial immunogenic components, particularly (i) the protective NspA surface protein, (ii) protein NMB2132 and (iii) protein NMB 1870. A Typical process involves the following steps: (a) treating bacterial cells in the substantial absence of detergent; (b) centrifuging the composition from step (a) to separate the outer membrane vesicles from treated cells and cell debris, and collecting the supernatant; (c) performing a high speed centrifugation of the supernatant from step (b) and collecting the outer membrane vesicles in a pellet; (d) re-dispersing the pellet from step (c) in a buffer; (e) performing a second high speed centrifugation in accordance with step (c), collecting the outer membrane vesicles in a pellet; (f) re-dispersing the pellet from step (e) in an aqueous medium.

The present invention relates to the field of Gram-negative bacterial vaccine compositions, their manufacture, and the use of such compositions in medicine. More particularly it relates to the field of useful Gram-negative bacterial outer membrane vesicle (or bleb) compositions comprising heterologously expressed Chlamydia antigens, and advantageous methods of rendering these compositions more effective and safer as a vaccine.

The invention discloses a preparation method and a drug carrying method of an escherichia coli outer membrane vesicle, and application of the outer membrane vesicle in anti-tumor. The preparation method of the escherichia coli outer membrane vesicle comprises the following steps of culturing a culture medium using LB in vitro, culturing an escherichia coli BL21 strain, performing centrifugation, filtration and ultrafiltration treatment to obtain an upper layer culture solution free of escherichia coli, and finally centrifuging the upper layer culture solution by a supercentrifuge to prepare the escherichia coli outer membrane vesicle. The particle size of the prepared escherichia coli outer membrane vesicle is uniform, and is about 50nm. Usually, a bacterium outer membrane vesicle is low in yield and difficult in drug carrying. The invention excogitates a novel drug carrying method for the bacterium outer membrane vesicle, so that the carrying efficiency of an anti-tumor drug can be significantly improved; an inhibition effect on multiplication and invasion of a tumor cell is increased; and a good application prospect of the bacterium outer membrane vesicle serving as a novel non-virus drug carrier is presented.

Method for the insertion of protein antigens, of recombinant or synthetic origin, in outer membrane vesicles of Gram-negative bacteria without disruption of the vesicle structure, therefore maintaining the immunogenicity and immunostimulatory properties of said vesicles, and with the reported advantage that the immune response generated against the incorporated antigen is superior to the one generated when the antigen is administered alone. The resultant vaccine formulations are useful to increase protective capacity of existing vaccines and allow to extend it against different pathogens, in diseases of bacterial, viral, cancerous or other etiology. The referred formulations are applicable in the pharmaceutical industry as vaccines for therapeutic and preventive use in humans.

The invention belongs to the technical field of medicines, and relates to drug-loaded nanoparticles, in particular to adriamycin nanoparticles entrapped by bacterial outer membrane vesicles and an application of the adriamycin nanoparticles. The invention provides adriamycin nanoparticles DOX-OMV which are entrapped by bacterial outer membrane vesicles and are prepared by adopting attenuated klebsiella pneumoniae sourced bacterial OMVs (outer membrane vesicles) to entrap a tumor chemotherapeutic drug DOX (doxorubicin). The test research on the effect of resisting non-small cell lung cancer shows that the DOX-OMV nanoparticles can play a lung cancer cell targeting role and an anti-tumor immune induction effect at the same time, and the half-life period of the drug is prolonged, so that the non-small cell lung cancer resisting curative effect of the chemotherapeutic drug adriamycin is remarkably enhanced, and the DOX-OMV nanoparticles have good safety. The prepared DOX-OMV nanoparticles can be used for preparing drugs for resisting non-small cell lung cancer.

The invention provides a vaccine and a preparation method thereof. The vaccine comprises bacterial outer membrane vesicles and antigen, wherein the antigen is combined with the bacterial outer membrane vesicles to form nanoparticles. The bacterial outer membrane vesicles are combined with a tumor specific antigen to prepare an anti-tumor vaccine, and an innate immune response and a specific immuneresponse are caused at the same time, so that the target of treating tumors by an autoimmune system of a body is achieved; and the vaccine is high in specificity, small in side effect and has a broadapplication prospect and great market value.

The invention provides a method for increasing the yield of outer membrane vesicles (OMVs) of bacteria and application of the OMVs of bacteria, and belongs to the technical field of biology. The method comprises the step of culturing a gram-negative bacteria mutant strain with an yjeE gene knocked out. The invention further provides application of the OMVs, prepared by the method, of the bacteriain preparation of a vaccine and an immunoenhancement. By use of the method, the yield of the OMVs of Escherichia coli reaches 701 mg / L, is increased by about 100 times than the culture yield of an original strain in an LB culture medium, the method is application to mass production of the OMVs in the pharmaceutical industry, and the production cost is significantly reduced. The OMVs, prepared by the method, of the bacteria have better immunoenhancement functions, can be added to common vaccines and can significantly enhance the immune effects.

The invention relates to a bacterial outer membrane vesicle, a nano vaccine containing the bacterial outer membrane vesicle as well as a preparation method and application thereof. The bacterial outermembrane vesicle contains molecular gluewater protein SpyCatcher and / or SnoopCatcher, the tumor vaccine comprises the bacterial outer membrane vesicle and an antigen connected with the bacterial outer membrane vesicle in the form of an isopeptide bond, and the antigen carries SpyTag and / or SnoopTag. According to the invention, the bacterial outer membrane vesicle containing molecular gluewater protein SpyCatcher and SnoopCatcher is used as a tumor vaccine platform and is connected with the antigen carrying SpyTag and / or SnoopTag to obtain the tumor vaccine, and the tumor vaccine can effectively activate an organism to generate innate immunity and realize specific killing of a plurality of antigens at the same time. According to the method, personalized tumor vaccines for tumors from different sources can be rapidly obtained.

This invention relates to outer membrane vesicles (OMVs) from Gram-negative bacteria. The vesicles comprise heterologous proteins or immunogenic fragments thereof expressed as lipoproteins in their membrane. The OMVs of the invention are capable of eliciting an immune response to the heterologous protein or to a fragment thereof when administered to a mammal. Other aspects of the invention relate to methods of preparing the OMVs and immunogenic compositions containing the same.

The invention relates to a nano-drug carrier wrapped by bacterial outer membrane vesicles and a preparation method of the nano-drug carrier. The carrier adopts outer membrane vesicles secreted by Escherichia coli to wrap polydopamine modified doxorubicin-loaded mesoporous silica nanoparticles, and the preparation method comprises the following steps: preparing the doxorubicin-loaded mesoporous silica nanoparticles, modifying the doxorubicin-loaded mesoporous silica nanoparticles by polydopamine, and extracting and purifying the outer membrane vesicles of bacteria. And preparing the nano-drug carrier OMVs-NPs wrapped by the outer membrane vesicles of the bacteria. The prepared OMVs-NPs can prevent the medicine from being released too early in a biological environment, outer membrane vesicles secreted by Escherichia coli have an adsorption effect on intestinal tracts, the OMVs-NPs serve as a biological outer membrane of a novel nano preparation, intestinal absorption of medicine carrying nanoparticles can be improved, the medicine is released after tumor cells are targeted, and the bioavailability of the medicine is improved.

The invention provides a bacterial outer membrane vesicle carrier as well as a preparation method and application thereof. The invention provides a vaccine universal vector OMV-SpyC-SPAb which is constructed on the basis of a B structural domain SPAb of staphylococcus aureus protein A, is based on bacterial outer membrane vesicles and can target dendritic cells, the B structural domain SPAb of the staphylococcus aureus protein A is displayed on the bacterial outer membrane vesicles and can be rapidly combined with an antibody (such as an Anti-DEC205 antibody) of the targeted dendritic cells, and a novel OMV-OVA-DEC vaccine capable of targeting the dendritic cells and obviously enhancing antigen intake is prepared by using the SpyCatcher / SpyTag molecular glue to display the antigen on the surface of the bacterial outer membrane vesicles, so that the cross presentation of the dendritic cells on the antigen can be promoted, and the specific immune response can be induced, thereby achieving the anti-tumor purpose and having a wide application prospect.

The invention discloses a modified zein nano drug delivery system wrapped by bacterial outer membrane vesicles as well as a preparation method and application of the modified zein nano drug delivery system. The medicine is dissolved in absolute ethyl alcohol, deionized water is added after ultrasonic dissolution, zein is added, and ultrasonic treatment is carried out; quickly adding a sodium caseinate solution into the obtained mixed solution while stirring, and stirring to obtain a modified zein drug-loaded nanoparticle solution; the preparation method comprises the following steps: uniformly mixing bacterial outer membrane vesicles with a modified zein drug-loaded nanoparticle solution, extruding the mixed solution for 2-8 times by using high-pressure nitrogen as an extrusion pressure source through a 200nm polycarbonate film, centrifuging the obtained product, and collecting the precipitate, thereby obtaining the bacterial outer membrane vesicle wrapped modified zein drug-loaded nanoparticle system. The nano drug-loading system provided by the invention is narrow in particle size distribution range and good in stability, and can load hydrophobic drugs which can be dissolved in ethanol, so that the solubility of the hydrophobic drugs in water is enhanced, and the stability and bioavailability of the drugs are improved.

The invention provides a fusion vesicle derived from bacteria and plants as well as a preparation method and application of the fusion vesicle, and relates to the technical field of biomedicine. The fusion vesicle comprises a mixed membrane structure formed by fusing a bacterial outer membrane vesicle and a plant thylakoid membrane, wherein the bacteria are gram negative bacteria, and the plant thylakoid is a spinach thylakoid. The fusion vesicle of the present invention combines the characteristics of the bacterial outer membrane vesicle and the plant capsular membrane, the structure of the vesicle is uniform, the vesicle can efficiently and rapidly reach the tumor, the tumor targeting property is high, and the accumulation time is long; and the obvious effect is realized in the aspect of tumor treatment.

The invention discloses a bacterial outer membrane vesicle coated supramolecular nanoparticle precursor, application and a drug delivery system, and relates to the technical fields of supramolecular chemistry, supramolecular materials and cell preparations. Based on the bacterial outer membrane vesicle coated supramolecular nanoparticle precursor, in-vivo immune cells can be specifically recognized, and an intracellular nanoparticle aggregate mediated by host-guest interaction is further constructed in cells. The endogenous immune cell carrier can respond to the inflammatory characteristics of focus tissues (such as tumors), so that the convenient trolley type delivery of intracellular nanoparticle aggregates is realized, and the excretion phenomenon of immune cells is inhibited. The preparation method of the in-vivo (and intracellular) supramolecular nanoparticle assembly mediated by the host-guest interaction has the advantages of being simple in preparation process, rapid and universal, and challenges faced by the construction and in-vivo delivery process of a cell carrier preparation can be overcome. In addition, the invention further provides a drug loading system, and drug loading of targeted drug therapy can be achieved.

A vaccine platform using a Yersinia pestis mutant synthesizing an adjuvant form lipid A (monophosphoryl lipid A, MPLA) for the increased biogenesis of bacterial outer membrane vesicles (OMVs). To enhance the immunogenicity of the OMVs, an Asd-based balanced-lethal host-vector system was constructed to oversynthesize the LcrV antigen of Y. pestis, raise the amounts of LcrV enclosed in OMVs by Type II secretion system, and eliminate harmful factors like plasminogen activator (Pla) and murine toxin from the OMVs. Vaccination with OMVs containing MPLA and increased amounts of LcrV with diminished toxicity afforded complete protection in mice against subcutaneous challenge and intranasal challenge and was significantly superior to that resulting from vaccination with LcrV / alhydrogel. Additionally, the Yersinia OMV can be used as a platform to deliver the heterologous antigens of Bacillus anthraces. Vaccination with multiantigenic self-adjuvanting bionanoparticles from Pseudomonas was also successfully tested in connection with Pseudomonas aeruginosa.

The present invention provides means and products for the stimulation of an immune response against tumors in a subject in need thereof. More specifically the invention provides immunogenic compositions containing bacterial outer membrane vesicles loaded with tumor antigens, fusion proteins comprising a bacterial protein and a tumor antigen, and isolated bacterial outer membrane vesicles (OMVs) containing said fusion proteins. The fusion proteins, OMVs and immunogenic compositions according to the invention are used in the prevention and treatment of tumors.

The invention discloses a drug-loaded bacterial outer membrane vesicle, and a preparation method and application thereof, and particularly relates to a drug-loaded bacterial outer membrane vesicle prepared with the aid of liposome and a preparation method and application of the drug-loaded bacterial outer membrane vesicle. The application is in particular application in the preparation of antibacterial drugs. The invention provides the method for preparing a preparation containing the drug-loaded bacterial outer membrane vesicle, the method comprises the following steps of taking a preparationcontaining a drug-loaded liposome and a preparation containing a bacterial outer membrane vesicle as raw materials, and preparing to obtain the preparation containing the drug-loaded bacterial outermembrane vesicle. The invention further provides the method for preparing the drug-loaded bacterial outer membrane vesicle, the method comprises the following steps of taking a drug-loaded liposome and a bacterial outer membrane vesicle as raw materials, and preparing to obtain the drug-loaded bacterial outer membrane vesicle. The invention further provides the antibacterial drugs, including the preparation containing the drug-loaded bacterial outer membrane vesicle or the drug-loaded bacterial outer membrane vesicle. According to the drug-loaded bacterial outer membrane vesicle, the preparation method and application thereof, broad application prospects in the field of drug delivery and the field of antibacterial drug development achieved.

The invention discloses a fusion membrane-coated bionic nanoemulsion as well as a preparation method and application thereof. The fusion membrane-coated bionic nanoemulsion is prepared by the following steps of: providing a bionic nanoemulsion, wherein the bionic nanoemulsion comprises a shell and a core positioned in the shell, the shell is composed of lactic oxidase and human serum albumin, and the core is composed of a perfluorinated compound; providing a fusion membrane, wherein the fusion membrane is formed by fusing an engineered cell membrane and a bacterial outer membrane vesicle; and coating the bionic nanoemulsion with the fusion membrane to obtain the fusion membrane-coated bionic nanoemulsion. The fusion membrane-coated bionic nanoemulsion disclosed by the invention can simultaneously realize the synergistic treatment of tumor by combining photothermal therapy, starvation therapy and immunotherapy, thereby having a good application prospect in the field of tumor diagnosis and treatment. Meanwhile, the preparation process disclosed by the invention is simple and convenient to operate, does not need complex and expensive equipment, and is easy to realize industrial production.

The present invention provides means and products for the stimulation of an immune response against tumors in a subject in need thereof. More specifically the invention provides immunogenic compositions containing bacterial outer membrane vesicles loaded with tumor antigens, fusion proteins comprising a bacterial protein and a tumor antigen, and isolated bacterial outer membrane vesicles (OMVs) containing said fusion proteins. The fusion proteins, OMVs and immunogenic compositions according to the invention are used in the prevention and treatment of tumors.

The invention belongs to the technical field of drug carriers, and discloses a biomimetic nano-drug delivery system and a preparation method and application thereof.The biomimetic nano-drug delivery system is prepared by mixing bacterial outer membrane vesicles on the basis of a nano-particle concentrated solution prepared from biodegradable polymers, cationic lipid and siRNA drugs and conducting ultrasonic treatment; the preparation method is simple and mild, the raw materials are easy to obtain, the preparation method is suitable for large-scale production, the prepared biomimetic nano-drug carrier is used as an anti-tumor drug, and a constructed drug delivery system is stable in structure, is highly enriched and detained for a long time at a tumor site, can doubly target dendritic cells and tumor cells, and has a good application prospect. The action effect of the anti-tumor medicine is obviously improved.

The present invention relates to the fields of medical microbiology and vaccines. In particular the invention relates to a process wherein the spontaneous release of bacterial outer membrane vesicles (OMV) of Gram-negative bacteria is stimulated by application of a dissolved oxygen tension (DOT) that is higher than a physiological DOT. The thus produced OMVs are for use in vaccines. The invention further relates to OMV obtainable by said process, and to a pharmaceutical composition comprising such OMV. The present invention further relates to the use of OMV of the present invention as a medicament in particular for use in a method for eliciting an immune response.

The invention discloses a hybrid nanovaccine with photothermal response and a preparation method thereof. The hybrid nanovaccine comprises magnetic mesoporous silicon, indocyanine green and staphylococcus aureus outer membrane vesicles (OMV). The invention uses bacterial OMV as the vaccine and the delivery carrier; at the same time, laser irradiation can make the indocyanine green produce heat topromote lysosome escape; reactive oxygen species (ROS) produced by lysosome rupture can further activate proteasomes to promote the processing of antigens; and finally, synergistic effect can be obtained to improve the immune effect of vaccine. The invention belongs to the field of pharmaceutical preparations and the technical field of bio-medicines. The nanovaccine is simple and controllable in preparation process, low in economic cost, good in repeatability and capable of effectively preventing the infection of drug-resistant staphylococcus aureus, with high clinical application value.

The invention discloses a preparation method of nanoparticles of calcium carbonate-polydopamine coated drug-loaded bacterial outer membrane vesicles, which comprises the following steps: (1) preparation of OMVs: carrying out continuous subculture on escherichia coli strains until the escherichia coli strains grow stably, then inducing activated escherichia coli in logarithmic phase by using an IPTG inducer to generate OMVs, and carrying out freeze drying on the OMVs to obtain the nanoparticles of the drug-loaded bacterial outer membrane vesicles; (2) preparing OMVs (Ti): forming the OMVs (Ti) from the OMVs separated in the step (1) and a fat-soluble TGF-beta inhibitor through a membrane fusion method under an ice-water bath ultrasonic condition; and (3) preparing CaCO3-PDA-OMVs (Ti): adding the OMVs (Ti), CaCl22H2O, Na2CO3 and dopamine into a Tris-HCl (0.25 mM)-HEPES (25mM) buffer solution, and preparing by a one-pot method. The drug-loaded nanoparticles prepared by the invention have the advantages of no toxicity, high-efficiency delivery of inhibitors, activation of autoimmunity and the like.

The present invention relates to a method of displaying an antigen with a eukaryotic carbohydrate component. The method involves providing a bacterial cell transformed with a nucleic acid construct encoding an antigen with a eukaryotic carbohydrate component and culturing the transformed bacterial cell under conditions effective to express the antigen with a eukaryotic carbohydrate component, associate the expressed antigen with a eukaryotic carbohydrate component and a lipid A core carbohydrate in the bacterial cell to form a lipo-carbohydrate complex, and display the lipo-carbohydrate complex on the surface of the bacterial cell. Also disclosed are a bacterial cell or a vesicle displaying on its outer surface a lipo-carbohydrate complex of an antigen with a eukaryotic carbohydrate component associated with a lipid A core carbohydrate as well as an antibody which recognizes the eukaryotic carbohydrate component of the bacterial cell or vesicle. The vesicle or antibody can be administered to a subject to raise an immune response against pathogen infection, to treat disease, or to treat cancer.