8076 results about "Biophysics" patented technology

The invention discloses an arginine decarboxylase diaA enzyme mutant and application thereof in preparation of butanediamine, and belongs to the field of bioengineering. According to the invention, rational charge overturning transformation is simultaneously carried out on a pentamer meridian oligomeric interface and a dimer latitudinal oligomeric interface, so that stable assembly and efficient catalysis of the decamer under the condition of neutral to alkaline pH (7.0-9.0) are realized. Wherein positive charges are introduced into a meridian interface to weaken electrostatic repulsion, and negative charges are introduced into a latitudinal interface to enhance dimer compactness and substrate transfer efficiency. The specific enzyme activity of the representative double mutant AdiAD110K / H736E at pH 8.0 is about 35 times that of a wild type, and the representative double mutant AdiAD110K / H736E keeps a complete decamer state in a pH range of 7.0-9.0. The yield of butanediamine is up to 145.9 g / L under the whole-cell catalysis of the mutant.

The invention discloses a rational copolymerization strategy for improving the stability of an oligomeric structure of acid-induced high-order oligomeric decarboxylase AdiA in a neutral to alkaline environment and application of the rational copolymerization strategy, and belongs to the field of bioengineering. According to the strategy, rational charge overturning transformation is carried out on a pentamer radial oligomeric interface and a dimer weft-wise oligomeric interface at the same time, and stable assembly and efficient catalysis of a decamer under the condition that the pH value is from 7.0 to 9.0 from neutral to alkaline are achieved. Wherein positive charges are introduced into a meridian interface to weaken electrostatic repulsion, and negative charges are introduced into a latitudinal interface to enhance dimer compactness and substrate transfer efficiency. The specific enzyme activity of the representative double mutant AdiAD471K / E467K / H736E is 45.5 times that of a wild type when the pH value is 8.0, and the representative double mutant AdiAD471K / E467K / H736E keeps a complete decamer state when the pH value is 7.0-9.0. The yield of butanediamine is up to 156.5 g / L by using the mutant to catalyze whole cells.

The invention relates to a curcumin-loaded MMP response type melittin nano-pellicle vesicle as well as a preparation method and application thereof, and belongs to the technical field of pharmaceutical preparations. The preparation method comprises the following steps: firstly, preparing curcumin entrapped lipidosome; then carrying out culture amplification on engineering bacteria carrying melittin recombinant plasmids, extracting cell membranes after removing cell walls, and carrying out ultrasonic treatment and membrane extrusion to obtain melittin cell membrane nano-vesicles; fusing the curcumin lipidosome and the cell membrane nano-vesicles in an ultrasonic extrusion mode to obtain fused vesicles; and finally, carrying out surface calcium phosphate mineralization treatment on the fused vesicles to obtain the curcumin-loaded MMP response type melittin nano pellicle vesicles. The nano mycofilm vesicle prepared by the invention can be used for preparing antitumor drugs, and the biocompatibility and in-vivo stability of nanoparticles are improved by introducing a calcium phosphate coating; through combined delivery of melittin and curcumin, the anti-tumor effect is enhanced, so that the growth and proliferation of tumor cells are inhibited.

The invention provides an enzyme response type supramolecular PDRN-mini ECM liposome and a preparation method and application thereof.The enzyme response type supramolecular PDRN-mini ECM liposome comprises phospholipid, a membrane stabilizer, a supramolecular compound and an emulsifier, a water phase formed by the supramolecular compound and the emulsifier serves as an inner core, and the supramolecular compound is formed by PDRN and mini ECM through intermolecular acting force; the mini ECM is formed by self-assembly of collagen peptide, elastin and hyaluronic acid. The supramolecular PDRN-mini ECM liposome with uniform particle size and good stability is obtained through a microfluidic technology, the process is simple, the controllability is high, and amplification is easy.

The invention relates to ultra-small prussian blue nano-particles (T-USPB-C) carrying tirofian, a preparation method of the nano-particles and application of the nano-particles in preparation of drugs for reducing MVO and MIRI. According to the preparation method, the T-USPB-C is prepared by three steps. The T-USPB-C provided by the invention can carry tirofiban, and has catalase and superoxide dismutase simulated nano-enzyme activity. Moreover, the size of the nano-scale drug is required to reach a nano-scale size, and the drug can be efficiently cleared through kidney excretion, so that the potential long-term toxicity problem is minimized. The ultra-small prussian blue nanoparticle carrying the tirofian has an excellent active oxygen scavenging capability. Microvascular perfusion can be rapidly improved through the antithrombotic effect, then the protection effect is continuously achieved through the anti-oxidation and anti-inflammatory mechanism, and microvascular injury and MIRI are effectively prevented.

The invention discloses a mixing device for apoptosis inducer stapharia rugosoannulata water-soluble protein, and relates to the field of water-soluble protein mixing equipment.The mixing device comprises a tank body, a top cover is detachably installed at the top of the tank body, and a feeding pipe and a discharging pipe are arranged at the top and the bottom of the side face of the tank body respectively; a top cover is arranged in the tank body, the bottom of the top cover is rotationally connected with a rotating shaft located in the tank body, a plurality of stirring blades are annularly installed at the bottom of the side face of the rotating shaft at equal intervals, the stirring blades are obliquely arranged, and when the rotating shaft drives the stirring blades to rotate, the stirring blades push liquid around the stirring blades to move downwards; and a support frame is mounted at the bottom of the inner wall of the tank body. According to the mixing equipment for the water-soluble protein of the cell apoptosis inducer, the mixing mode of the water-soluble protein is optimized, so that the water-soluble protein can be converged and mixed for multiple times at different degrees in the mixing process, the influence of reduction of the rotating speed of a stirring paddle can be overcome, and the high-efficiency mixing work of the water-soluble protein is ensured.

The invention provides a method for detecting an external vesicle marker through high-flux nano plasma exciting light immune color development, and belongs to the technical field of human extracellular vesicles. After a serum sample is subjected to centrifugal treatment, the serum sample and a CD81 capture antibody substrate are incubated, and the particle size distribution of the vesicles is monitored in real time; a zwitterionic polymer modified gold nanoparticle LAM detection probe and a polyethylene glycol modified silver nanoparticle LprG detection probe are prepared to be specifically combined with a vesicle surface antigen, a chromogenic enhancement solution is adopted to induce a plasma resonance signal, and full-hole scanning imaging is carried out; and constructing a double-layer game optimization model to cooperatively optimize the detection sensitivity and the signal stability, carrying out weighted summation on normalized signals of the particle size subgroups to obtain comprehensive detection signal intensity, comparing the comprehensive detection signal intensity with a threshold value, and outputting a final judgment result. The technical problem that quantitative accuracy is affected by signal intensity deviation caused by vesicle particle size difference in outer vesicle marker detection is solved.

The invention discloses an engineered bionic nucleic acid nano-vesicle as well as a preparation method and application thereof, relates to the technical field of nano biomedicine, and aims at solving the problems that in-vivo targeting efficiency and immunogenicity of a traditional cationic lipid nano-carrier are limited due to deletion and cleavage obstacles of GSDMD expression in tumor cells. The technical key point of the invention is as follows: the engineered bionic nucleic acid nano-vesicle is provided and is prepared by wrapping a cationic lipid nucleic acid drug with an exosome derived from engineered macrophages; wherein the exosome from the engineered macrophage is the exosome from the macrophage with high expression of PD1, which is as shown in SEQ. ID. NO.1. The exosome from the engineered macrophage is the exosome from the macrophage with high expression of PD1; the lipid nucleic acid medicine is prepared by loading GSDMD-N mRNA (messenger Ribonucleic Acid) shown on the basis of SEQ.ID.NO.2 on a cationic liposome. The engineered bionic nucleic acid nano-vesicle is used for preparing an oral squamous cell carcinoma diagnostic kit and a therapeutic drug.

The invention discloses an enzyme immobilization method based on charge directed crosslinking, and belongs to the technical field of enzyme immobilization. The method sequentially comprises the following steps: reacting an enzyme with a modifier containing an anionic group to generate an electronegative modified enzyme; dissolving a protonated amino carrier in an acidic buffer solution to form a first solution, and dispersing a dissociation anion group-containing carrier and a modification enzyme in an alkaline buffer solution to form a second solution; mixing the two solutions, and constructing a gel network immobilized enzyme through electrostatic crosslinking; and finally, strengthening the gel network by using a multivalent metal ion solution. Directional anchoring of the enzyme in the gel is achieved through charge matching, the network stability and the enzyme microenvironment are synchronously optimized in combination with metal ion coordination, use of a covalent cross-linking agent is avoided in the whole process, conformation damage of an enzyme active center is avoided, the activity retention rate, the operation half-life period and the substrate mass transfer efficiency of the immobilized enzyme are remarkably improved, and the immobilized enzyme has good application prospects. The method is suitable for efficient immobilization of industrial enzymes such as beta-glucosidase, and has high biocompatibility and industrial potential.

The invention belongs to the technical field of immunodetection, and discloses a kit for detecting the ratio of proBDNF to maure BDNF based on structural dynamics guidance and a preparation method of the kit, the kit comprises a solid phase carrier and a detection reagent, the three antibodies are determined on the basis of full-length conformational kinetics analysis of brain-derived neurotrophic factors; the first capture antibody targets an innate disorder region (SEQ ID NO: 1) of a proBDNF propeptide region; the second capture antibody targets an innate disorder region (SEQ ID NO: 2) of a proBDNF propeptide region; the second capture antibody is a neo-epitope specific antibody, is specifically combined with an N terminal (SEQ ID NO: 2) exposed by maure BDNF enzyme digestion, and is combined with a free alpha-amino group strictly dependent on the first histidine; and the universal detection antibody is combined to a Loop 4 region (SEQ ID NO: 3) of the Mature structural domain. The problems of steric hindrance and cross reaction in traditional immunodetection are solved through a structural biology strategy, and accurate distinguishing and ratio quantification of proBDNF and maure BDNF are achieved.

The present invention relates to a microfluidic device (1) for forming a cell aggregate comprising at least one first cell (C1) and one second cell (C2), and for individually processing selected cells of the cell aggregate: - Microfluidic channel (10); - At least one main inlet (11) for fluids containing a first cell, a second cell, and a third cell, respectively, located in the first portion (101) of the microfluidic channel; - An outlet (12) located in the second portion (102) of the microfluidic channel for controlling the flow rate of fluid within the microfluidic channel; - A first auxiliary inlet (131) for at least one first auxiliary fluid, located in the first portion (101) of the microfluidic channel upstream or downstream of the main inlet (11); - At least one cell trapping section (14) positioned between the first and second parts within the microfluidic channel; - At least one first valve to control the flow rate of the first auxiliary fluid, causing the fluid containing the first cells and the second cells to flow at a predetermined height within the microfluidic channel, thereby guiding the first cells and the second cells to the first and second capture units, respectively. Equipped with, The microfluidic device relates to a microfluidic device in which each cell capture section (14) comprises at least one first capture section (141) and one second capture section (142), each first and second capture section being sized to accommodate a first or second cell, the first and second capture sections being adjacent to each other in a direction perpendicular to the bottom (100) of the microfluidic channel, and forming a cell aggregate containing the captured first and second cells, each cell being at a different height relative to the bottom of the microfluidic channel.

This invention provides a process for sequencing single-stranded DNA by employing a nanopore and modified nucleotides.

Provided are a method and system for enriching natural killer (NK) cells in a blood sample.

The invention discloses starch-collagen composite hydrogel as well as a preparation method and application thereof. Collagen is catalyzed by microbial transglutaminase to form a covalent cross-linked network, and meanwhile, hydroxypropyl starch is introduced to construct a physical interpenetrating network through molecular chain penetration and hydrogen-bond interaction; and chondroitin sulfate is further integrated to strengthen the network structure and biological activity through electrostatic interaction. The method is mild in condition and does not need a toxic chemical cross-linking agent, the obtained composite hydrogel has an interpenetrating double-network structure and has excellent mechanical properties, enzymatic degradation resistance and cell affinity, the compression modulus of the composite hydrogel is remarkably improved, the composite hydrogel can keep structural stability for a long time in a collagenase environment, cell adhesion and proliferation can be effectively promoted, and the composite hydrogel has a good application prospect. The hydrogel can be widely applied to tissue engineering scaffolds, wound dressings, drug sustained-release carriers and cartilage repair materials.

The invention discloses a chimera for degrading a CARD structural domain protein aggregate and application of the chimera. The chimera is prepared from light-operated targeting protein and light-operated degradation protein, the light-operated targeting protein is sequentially connected by an MAVS CARD structural domain, a flexible connecting peptide and a photosensitive protein pMag; the light-controlled degradation protein is sequentially connected by a photosensitive protein nMag, a flexible connecting peptide and an RING structural domain of TRIM21. According to the application, a light-operated activated CARD-RING chimera is constructed, and when the CARTAC generates toxic and side effects or in cells with RIG-I / MDA5 signal channels abnormally activated, the activity of the CARTAC can be effectively controlled or autoimmune diseases caused by RIG-I / MDA5 abnormity can be inhibited.

The invention provides a cell protein degradation platform based on an artificial biological macromolecular aggregate. Specifically, the invention provides a PROTAC functional module based on an interworking nucleic acid skeleton, a PROTAC-aggregate complex (MLO-PROTAC), a kit, application and a preparation method of the PROTAC functional module, the PROTAC-aggregate complex (MLO-PROTAC) and the kit, and also provides a targeted protein degradation method. In a PROTAC platform built by the PROTAC functional module and the PROTAC-aggregate complex, a programmable nucleic acid component is used as a core assembly unit, and the functional module is enriched and spatiotemporal-spatial regulation is performed by using the polypeptide aggregate, so that the delivery efficiency and the cytoplasm exposure degree are remarkably improved while the universality is maintained, and the delivery efficiency and the cytoplasm exposure degree are remarkably improved. Therefore, a more effective target protein degradation way is provided for the field.

The invention discloses application of a stem cell exosome in treating depression-like behaviors caused by high-altitude hypoxia, and belongs to the technical field of biomedicine. The stem cell exosome is an exosome derived from human umbilical cord mesenchymal stem cells, and is used for drugs for preventing and / or treating depression-like behaviors caused by high-altitude hypoxia. The exosome can effectively improve depression-like core behavior symptoms caused by high-altitude hypoxia by regulating a brain-intestinal axis; the method starts from remodeling intestinal flora so as to influence the intracerebral metabolite spectrum, and finally plays a role in neuroprotection by regulating and controlling a 5-HT6 / cAMP-PKA key signal channel. In addition, the combination of the hUC-MSC-exo and probiotics shows synergistic interaction potential, and a potential treatment strategy which is novel in mechanism, remarkable in effect and high in safety is provided for the field.

The invention relates to the technical field of biological medicine, in particular to a nano-vesicle for targeted brain glioma metabolic immune remodeling and a preparation method and application thereof. According to the nano-vesicle for targeted brain glioma metabolism immune remodeling, double-target metabolism and cascade responsive cleavage site modified biological vesicles are integrated, and effective penetration of a drug blood brain barrier and precise targeting of brain glioma can be achieved. The ROS responsive nanoparticles II are prepared by selecting BSA as a drug carrier, applying a nanoprecipitation method and utilizing SLC1A5, LDHA antagonists and responsive linkers, so that the metabolic double-target inhibitor only responds to specific ROS of tumor cells, and specific release in the tumor cells is realized. The cascade response polypeptide provides a simple and convenient delivery scheme with low invasiveness and application prospects for treatment of brain glioma, and is expected to realize precise and individualized treatment in the field of treatment of malignant glioma.

The invention relates to a UGT enzyme subtype substrate specificity prediction method and model. On the basis of a directional message passing neural network, graph structure characterization of a small molecule compound and features of specific protein binding sites of UGT enzyme are deeply fused, a bimodal prediction normal form of'molecule + protein binding sites' is designed, a deep learning model is constructed, conversion from compound center prediction to molecule-enzyme binding site comprehensive prediction is achieved, and the prediction accuracy is improved. And accurate classification prediction can be carried out on UGT enzyme substrates and non-substrates.

The invention relates to the technical field of biomedical materials, in particular to engineered small extracellular vesicle hydrogel enriched with PD-L1 and Siglec-15 as well as a preparation method and application of the engineered small extracellular vesicle hydrogel. The engineering small extracellular vesicle hydrogel is enriched with PD-L1 and Siglec-15 at the same time, the engineering small extracellular vesicle hydrogel comprises a hydrogel base body and PDL1-Siglec15-sEVs loaded in the hydrogel base body, and the PDL1-Siglec15-sEVs are small extracellular vesicles with the PD-L1 and the Siglec-15 in an overexpression mode. Compared with natural small extracellular vesicles and a traditional wound surface treatment strategy, the engineered small extracellular vesicle hydrogel has the advantages that PD-L1 and Siglec-15 can be enriched in the vesicles, so that more accurate immune microenvironment regulation and control can be realized on the local part of a wound surface, excessive inflammatory response is moderately inhibited, phenotype transformation of macrophages to be beneficial to tissue regeneration is promoted, and the wound surface treatment effect is improved. The hydrogel is used as a carrier and can provide a moist healing environment and a three-dimensional scaffold structure, so that the residence time of the engineered small extracellular vesicles on the local wound surface is remarkably prolonged, and slow release is realized.

Described herein are muscle-specific targeting moieties and compositions including the muscle specific targeting motifs. Also described herein are uses of the muscle-specific targeting motifs and compositions including the muscle specific targeting moieties. In some embodiments, the muscle-specific targeting moieties and compositions including the muscle specific targeting moieties can be used to direct delivery of a cargo to a muscle cell.

The invention belongs to the technical field of biological medicine, and particularly relates to an engineered cell microvesicle and a delivery system based on the engineered cell microvesicle, the system realizes efficient preparation of 1-5 [mu] m cell microvesicles, and the cell microvesicles have a large space volume and can be used for preparing the cell microvesicles. The carrier can be used for loading and delivery of target protein, polypeptide and recombinase which are specifically expressed in mother cells. The system transfects mother cells through lentivirus transfection or plasmid transfection to further produce cell microvesicles, and the microvesicles can load more goods and inherit membrane proteins of the mother cells, and can also effectively load intracellular proteins to realize effective delivery. By virtue of good structural stability, high immunogenicity and excellent biocompatibility, the cell microvesicle reduces systematic toxic and side effects of a traditional carrier, is expected to become an effective drug delivery system, and has great application potential in the field of gene therapy.

Described herein are targeting moieties that can be capable of specifically targeting muscle cells and can include an n-mer motif. In some embodiments, the n-mer motif contains an RGD motif. Also described herein are vector systems, particles, polypeptides that can encode and / or contain one or more targeting moieties. Also described herein are methods of delivering a cargo to a cell, such as a muscle cell, using one or more of the targeting moieties described herein.

The invention discloses a temperature-sensitive hydrogel loaded with mesenchymal stem cell exosome as well as a preparation method and application of the temperature-sensitive hydrogel, and belongs to the technical field of biological medicines. The method comprises the following steps: (1) adding poloxamer 407 into a pre-cooled dispersion medium to enable the final mass concentration to be 20-30%, and oscillating and dissolving at 4 DEG C overnight to obtain poloxamer hydrogel; (2) collecting a mesenchymal stem cell culture supernatant, and then centrifuging, wherein the centrifuging condition is 200 * g * 15 minutes to 2000 * g * 20 minutes to 12000 * g * 20 minutes; filtering the supernatant, concentrating by using an ultrafiltration tube, further performing ultracentrifugation on the concentrated solution, re-suspending the precipitate by using DPBS, centrifuging again, and re-suspending the finally obtained exosome precipitate by using DPBS to obtain an exosome suspension; the ultracentrifugation condition is as follows; and (3) taking the poloxamer hydrogel prepared in the step (1), adding the exosome suspension obtained in the step (2) under an ice-water bath condition, and uniformly mixing to obtain the poloxamer temperature-sensitive hydrogel.

The invention discloses light-driven toxin-enriched composite hydrogel as well as a preparation method and application thereof. The composite hydrogel comprises light-driven hydrogel and detection hydrogel, the light-driven hydrogel is agarose hydrogel doped with Au (at) Ag core-shell nano particles; the detection hydrogel is a double strand formed by an okadaic acid aptamer and a complementary sequence cDNA thereof, and a double strand formed by a domoic acid aptamer and a complementary sequence DNAzyme thereof, the hairpin H1 is used for modifying a quenching group BHQ2 at the 3'end, the hairpin H2 is used for modifying a fluorophore Cy3 at the neck part, the hairpin H3 is used for modifying a fluorophore FAM and a quenching group BHQ1 at the two ends respectively, and the metal ion doped agarose hydrogel is used for catalyzing DNAzyme cyclic shearing; and the photo-thermal driving unit is positioned on the detection function unit. According to the present invention, with the composite system of upper layer photo-thermal enrichment and lower layer dual-signal detection, the rapid and high-sensitivity simultaneous detection of the okadaic acid and the domoic acid is achieved through the combination of the photo-thermal transpiration effect and the HCR and DNAzyme cyclic shearing reaction;

The embodiment of the invention discloses a protein-ligand interaction prediction method and a related device. Determining a prediction interaction pair formed by atoms of the protein and atoms of the ligand molecule according to the data of the protein and the data of the ligand molecule, establishing a loss function according to the node characteristics and the edge characteristics of the real interaction pair and the node characteristics and the edge characteristics of the prediction interaction pair, and adjusting model parameters according to the loss function, the target neural network model can be used for predicting the interaction between any protein and ligand molecules. Physical priori knowledge of protein-ligand interaction is fused in model training and prediction, so that the model can learn characteristics with more biological significance, and the predicted biological correlation is improved. According to the method, the advantages of deep learning are utilized, high-dimensional features are automatically extracted, complex pattern recognition is carried out, the complex relation in protein-ligand interaction is captured, and the stability and accuracy of protein-ligand interaction prediction are improved.

The invention discloses a method for preparing butanediamine and spermidine from whole cells, and belongs to the field of bioengineering. According to a rational copolymerization modification strategy, a meridian interface and a latitudinal channel interface of arginine decarboxylase are subjected to rational modification respectively or simultaneously, and a series of mutants are obtained. The optimal mutant AdiA H729D / E467K / H736E, which is subjected to double-interface synergistic modification, disclosed by the invention, keeps high activity in the whole neutral-alkaline range of pH (Potential of Hydrogen) of 7.0 to 9.0. The optimal pH of the arginine decarboxylase mutant is increased, the enzyme activity stability in a neutral pH range is improved, the arginine decarboxylase mutant is more suitable for the condition requirements of industrial microbial fermentation, and a foundation is laid for efficient synthesis of butanediamine. The spermidine yield is up to 153.3 mg / L by using the mutant to catalyze the whole cell.

According to the cell fixing liquid, phenol oxidase is used for catalyzing phenol to be oxidized into a quinone structure, the quinone structure reacts with protein amido to form light covalent immobilization, cell immobilization is achieved, a stable hydration environment and membrane protection are provided through the ionic liquid solvent choline dihydrogen phosphate, a phosphate-free buffer system is provided, and cell immobilization is achieved. Therefore, a novel cell fixing liquid is obtained, the cell structure integrity required by cell imaging analysis is effectively reserved, meanwhile, cell staining fluorescence signal interference is avoided, and therefore the accuracy of cell counting and cell imaging analysis is ensured.

The invention belongs to the technical field of exosome freeze-dried powder, and discloses exosome freeze-dried powder and a preparation method thereof, the exosome freeze-dried powder contains mesenchymal stem cell exosome, trehalose, sodium hyaluronate, hydroxypropyl-beta-cyclodextrin, glutathione, ceramide and fructo-oligosaccharide. According to the exosome freeze-dried powder, hydroxypropyl-beta-cyclodextrin, glutathione, ceramide and fructo-oligosaccharide are added, the membrane structure integrity of the exosome is effectively protected, the retention rate of active substances in the exosome freeze-dried powder is high, and therefore the effects of resisting inflammation, regulating cell metabolism, promoting tissue repair and the like of the exosome can be fully exerted. In addition, glutathione can directly remove skin free radicals and inhibit oxidative stress injury, and has an anti-oxidation effect; ceramide can also supplement skin lipid barrier, enhance the water locking capacity and enhance the moisturizing effect of sodium hyaluronate; fructo-oligosaccharide can also regulate skin micro-ecological balance, and has anti-inflammatory and bacteriostatic effects.