13 results about "Molecular modification" patented technology

The application provides a liquid crystal biosensor based on functional nucleic acid regulation of CRISPR-Cas12a for high-sensitivity visual detection of protein markers and a preparation and detection method thereof. The sensor comprises a ready-to-use detection reagent and a nucleic acid molecule functionalized liquid crystal detection interface. The ready-to-use detection reagent comprises the following elements or components: a Cas enzyme-crRNA complex with shearing activity and an aptamer-activating sequence-two-dimensional material-based activating sequence locking system. The nucleic acid molecule functionalized liquid crystal detection interface is a DNA molecule or RNA molecule modified liquid crystal interface, wherein the nucleic acid aptamer specifically recognizes the target protein. The sensor of the application is simple and convenient to operate, does not require excessive manpower, has high sensitivity, and can realize semi-quantitative or quantitative detection.

The application discloses a preparation method of chitosan microspheres for cell immobilization and drug delivery, and relates to the field of chitosan microsphere preparation. The application carries out deacetylation on chitin through a microwave induction process technology combined with enzymes, carries out heavy metal green chelation on chitosan by using glutamic acid diacetic acid tetrasodium or citric acid, further improves the extraction and removal capacity of the chelating agent on residual metal ions by using a carbonate salt solubilization technology, and separates and hydrolyzes trace amounts of protein and lipids in the crude chitosan by selecting appropriate biological enzymes to obtain refined chitosan. Meanwhile, the refined chitosan is subjected to enzymatic molecular modification by applying transglycosylation or oxidase, and finally, the chitosan microspheres are prepared by using a green and environment-friendly spray drying method. The chitosan microspheres prepared by the application are smooth in shape, uniform in size, have a particle size of 1-250 mu m, and have a shell-core structure. The chitosan immobilized enzyme widens the application of chitosan in the fields of medicine, food and the like.

The application provides a kind of tea polyphenol ester-RNA self-assembly and hybrid nanovesicle of probiotic outer membrane vesicle and preparation method thereof, which first adjusts the hydrophilicity and hydrophobicity of tea polyphenol EGC through molecular modification strategy, and the EGC palmitate obtained by modification can directly wrap RNA and self-assemble into tea polyphenol ester-RNA nanovesicle, which has superior encapsulation capacity. Further introduce OMVs as intestinal targeted delivery carrier and fuse with RNA-tea polyphenol nanovesicle to form a structure stable hybrid vesicle. The hybrid vesicle of the application ingeniously integrates the advantages of both sides: tea polyphenol ester-RNA nanovesicle ensures efficient encapsulation of RNA, and OMVs provide natural protection for its translocation through gastrointestinal tract, and promote intestinal cell uptake with its inherent bioadhesion. This strategy can effectively promote the encapsulation and stabilization of oral RNA delivery.

The present application provides an anti-ultraviolet polydimethylsiloxane food packaging coating and a preparation method thereof, which realizes the dual synergy of anti-ultraviolet and food preservation function through molecular modification, and introduces degradable materials to enhance environmental protection. The coating embeds anti-ultraviolet groups and preservation groups into the polydimethylsiloxane main chain through chemical bonds, avoiding the migration of traditional additives. A one-step in-situ polymerization process is used to ensure uniform distribution of functional groups, solving the problems of uneven function and migration. The coating provides ultraviolet protection, antibacterial, ethylene absorption, water retention, and prolongs the shelf life of food. The coating also uses degradable materials to reduce environmental pollution. It is suitable for outdoor circulation and transparent packaging scenarios, providing an efficient, safe and environmentally friendly packaging solution.

This invention discloses a bifunctional small-molecule PEG-modified recombinant humanized collagen and its preparation method. The method includes the following steps: preparing a borate buffer solution containing sodium cyanoborohydride, pH 7.5-8.5; dissolving lyophilized recombinant collagen powder in the buffer solution to obtain a substrate solution; adding crosslinking agent powder to the substrate solution according to a molar ratio of free lysine to crosslinking agent of 1:(1.5-4.0); the crosslinking agent is a bifunctional small-molecule PEG with PEG as the backbone and groups at both ends that can couple with the amino groups of collagen; reacting at 4°C in the dark for 2-5 hours. This invention not only overcomes the bottleneck of anti-enzymatic stability but also transforms recombinant humanized collagen into a multi-arm macromolecular crosslinking substrate with highly active groups on its surface, providing key chemical bonding sites for its subsequent targeted coupling or anchoring to polymer networks such as hydrogels.

The application discloses an enzyme mutant in a folate synthesis pathway and application thereof. The enzyme mutant comprises AtDRTS2M, and the amino acid sequences of the AtDRTS2M are respectively shown as SEQ ID NO:1, and the gene sequences of the AtDRTS2M are respectively shown as SEQ ID NO:2. The application carries out molecular modification on the related enzymes in the folate synthesis pathway, so that the biological activity of the modified AtDRTS2M in a plant body is higher, and technical support is provided for cultivating a high-yield folate crop.

This application discloses a method, apparatus, device, and readable storage medium for reconstructing molecular structures, relating to the field of machine learning. The method includes: acquiring a reference molecule; structurally decomposing the reference molecule to obtain at least one set of molecular fragments corresponding to the reference molecule; performing feature processing on the molecular fragment sets to obtain candidate fragments for replacing the fragmented fragments; and generating a reconstructed molecule based on the candidate fragments and side chain fragments. By structurally decomposing the reference molecule to obtain fragmented fragments and side chain fragments, the structure of the new molecular fragments replacing the fragmented fragments is predicted using the side chain fragments as structural conditions, resulting in candidate fragments. In other words, the molecule is segmented and the construction rules of related fragments are learned. The newly generated candidate fragments are used to replace the fragmented fragments on the original molecule to achieve molecular modification. The generated molecules have a considerable probability of breaking out of the structural rules of existing molecular structures, thereby improving the success rate of molecular reconstruction.

The invention relates to the technical field of biological materials, in particular to a bionic nerve conduit and a preparation method and application thereof. Through layered functional design, the multifunctional nerve conduit which sequentially comprises an inner layer, a middle layer and an outer layer from inside to outside is prepared. Wherein the inner layer is used for constructing parallel oriented nanofibers through an electrostatic spinning technology, and is connected with divalent metal ions after being modified by connecting molecules, so as to regulate and control the behaviors of endothelial cells and blood vigor cells; the middle layer adopts a melt spinning technology to form micron fibers which are arranged in a crossed manner, so that sufficient radial and circumferential mechanical support is provided to enhance the deformation resistance; the outer layer utilizes an electrostatic spinning technology to construct compact and randomly arranged nanofibers, so that on one hand, fibrosis infiltration can be prevented; on the other hand, the structural integrity can be effectively ensured. The bionic nerve conduit provides a new material and a new strategy with clinical transformation potential for peripheral nerve defect repair in a complex environment.

This invention belongs to the field of enzyme engineering, specifically relating to a thermostable sucrose synthase mutant and its applications. Based on the amino acid sequence of sucrose synthase shown in SEQ ID NO:1, this invention utilizes rationally designed molecular modification techniques to perform site-directed mutagenesis, resulting in a significantly improved thermostability of the modified sucrose synthase mutant. The mutant enzyme was obtained by inducing expression and purifying the protein from the resulting mutant strain. Compared to the wild-type sucrose synthase, the mutant exhibits a half-life that is extended from 42.88 min to 679.41 min at 50°C, which is 15.8 times that of the wild-type; and at 55°C, the half-life is increased from 12.94 min to 110 min, reaching 8.5 times that of the wild-type, thus better suited for industrial production.

This invention discloses an imine reductase mutant and its application in the catalytic synthesis of chiral 1-aminoindenhydrin derivatives. This invention utilizes protein engineering to synthesize an imine reductase mutant derived from *Neosatoria* (…). Neosartorya fumigata imine reductase Nf RedAm underwent molecular modification to obtain a mutant with high activity, high stability, and high substrate tolerance. This mutant can efficiently catalyze the asymmetric reduction of 1-indanone: under optimal conditions, the substrate concentration reaches 10.56 g·L⁻¹. ‑1 Whole-cell catalyst M3 catalyzes the synthesis of products ( R The cumulative concentration of γ-rezagilan reached 11.2 g·L⁻¹. ‑1 The enantioselectivity reaches 98%. Simultaneously, this mutant also exhibits highly efficient catalytic activity and excellent stereoselectivity for 1-indanone derivatives substituted with methyl, halogen, or cyano groups, with product enantioselectivity > 99%. This imine reductase mutant possesses extremely high catalytic activity and substrate tolerance, showing strong industrial application potential in the asymmetric synthesis of chiral 1-aminoindanone derivatives.

This invention proposes a coordination assembly-modified microorganism, its preparation method, and its application, belonging to the field of biomedical materials technology. This invention obtains catechol lipid-modified microorganisms by reacting catechol lipid molecules with microbial culture via a thin-film hydration method. These microorganisms are then contacted with metal ions to form a catechol lipid-metal-modified microorganism through coordination. Further contact with polyphenolic compounds leads to the coordination assembly of a catechol lipid-metal-polyphenol complex, thus forming the coordination assembly-modified microorganism. This invention employs a novel bacterial surface coordination assembly method and, through the combined regulation of microorganisms and inflammatory mediators, achieves a combined treatment of periodontitis and neuroinflammatory conditions related to depression and cognitive impairment. The modification method of this invention is universal; it can be used to construct engineered bacteria by replacing different bacterial carriers and different metals and polyphenolic compounds.