76 results about "Moist heat sterilization" patented technology

The invention discloses a preparation method of a high-adsorbability aluminum hydroxide adjuvant for livestock, which comprises the following steps: when an aluminum chloride solution reacts with alkali liquor, generating a colloidal suspension by combining pH two-step adjustment with dispersant addition; and after instant high-speed shearing and room-temperature aging, performing ultrafiltration purification to remove salts, and finally performing moist heat sterilization to obtain the suspension morphological adjuvant. The adjuvant is high in antigen adsorption rate, low in 72-hour desorption rate, large in specific surface area, uniform in particle and suitable for vaccines of pigs, cattle and poultry, and the problems that a traditional adjuvant is low in adsorption rate and poor in stability are solved.

The invention belongs to the technical field of medical and mechanical combinations, and discloses a high-permeability and low-sensitivity ripdicaine wound patch and a preparation method thereof.The high-permeability and low-sensitivity ripdicaine wound patch comprises a wound patch body, and the wound patch body is prepared from, by mass, 0.1%-0.4% of sodium hyaluronate, 1.5%-3.5% of lidocaine, 1.5%-3.5% of prilocaine, 3%-10% of solvent, 0.5%-8% of emulsifier, 2%-10% of humectant, 0.1%-5% of soothing agent, 0.1%-1.5% of stabilizer, 0.1%-1% of thickener and the balance water. According to the present invention, the total amount of the raw materials is 100%, the total amount of the raw materials is 100%, the total amount of the raw materials is 100%, the total amount of the raw materials is 100%, the total amount of the raw materials is 100%, the total amount of the raw materials is 100%, the total amount of the raw materials is 100%, the total amount of the raw materials is 100%, and the total amount of the raw materials is 100%. And the anesthetic has the advantages of quick effect taking, low sensitivity, capability of resisting moist heat sterilization and good stability.

The invention belongs to the field of gene engineering. In particular to high-stability recombinant XVII type collagen as well as a preparation method and application thereof. The recombinant XVII type collagen is obtained by repeating an amino acid sequence (as shown in SEQ ID NO.1) from a natural human XVII type collagen peptide for 2-5 times. The recombinant XVII type collagen can also be secreted and expressed in a pichia pastoris expression system, the preparation method is simple, and the high-yield recombinant XVII type collagen can be obtained at low cost. The cell proliferation, migration and adhesion promoting activities of the recombinant XVII type collagen are obviously superior to those of commercially available XVII type collagen, a triple helix structure can be formed at room temperature, a 1% aqueous solution has high-temperature stability and moist heat sterilization stability, and the recombinant XVII type collagen can be widely applied to the fields of cosmetics and medical instruments.

The invention relates to the technical field of biological materials, in particular to a PDRN porous microsphere as well as a preparation method and application thereof. The PDRN porous microspheres are prepared from the following raw materials: PDRN, an oil phase matrix, a curing agent and metal salt, the curing agent is at least one of polyethylene glycol acrylate and polylysine; the metal salt is at least one of calcium chloride, zinc chloride, magnesium chloride and ferric chloride. The PDRN porous microsphere has the advantages of being controllable in size, excellent in disintegration resistance and excellent in swelling resistance, is high in moist heat sterilization tolerance and strength, can be used as a filling material for medical beauty or an ideal candidate material of a tissue engineering scaffold, and has potential application value.

The invention discloses a poly-deoxyribonucleotide salt and a preparation method and application thereof, the content of the poly-deoxyribonucleotide salt is greater than 95%, the protein content is less than 1.0%, and after high-pressure moist heat sterilization, the dynamic viscosity reduction amount does not exceed 25%, and the elastic index G'reduction amount does not exceed 30%. The polydeoxyribonucleotide salt disclosed by the invention is simple in preparation process, short in production period, low in cost and suitable for large-scale industrial production; and the preparation process is mild, few impurities are introduced, the product structure is less damaged, and the preparation method is environment-friendly. The polydeoxyribonucleotide salt disclosed by the invention has good physical support performance, has the effects of promoting skin cell repair, resisting skin sensitivity, whitening, resisting inflammation, preventing alopecia and growing hair, and has a wide market prospect.

The invention relates to the technical field of films, in particular to a preparation method and application of a waterproof and oil-proof ventilation valve for food packaging. The preparation method comprises the following steps: carrying out plasma activation treatment on the porous polytetrafluoroethylene-based membrane; preparing fluoroalkyl silane modified silicon dioxide nano particles; preparing fluorine-containing organic silicon-silicon dioxide sol containing vinyl; a cross-linking layer is constructed through vacuum impregnation; preparing a hydrophilic / hydrophobic comonomer solution; copolymerized chain grafting is initiated by ultraviolet light; and water-based fluorocarbon emulsion is sprayed on the surface for curing. The obtained breather valve has super-hydrophobic and oleophobic characteristics, keeps high air permeability and high water vapor permeability at the same time, has the air permeability retention rate exceeding 95% after 10 times of moist heat sterilization, and is suitable for balancing internal and external pressure and blocking water and oil phase liquid permeation in the high-temperature and high-pressure sterilization process of a food packaging container.

Disclosed in the present invention are a composition comprising microspheres and crosslinked hyaluronic acid or a salt thereof, and a preparation method therefor and a use thereof. The composition comprises crosslinked hyaluronic acid or a salt thereof, microspheres, a phosphate buffer, and non-crosslinked hyaluronic acid or a salt thereof. In the present invention, under a condition of a large amount of an alkali solution, a mixture of high- and low-molecular-weight hyaluronic acid or a salt thereof is used to form a loose structure; under a condition of a small amount of an alkali solution, low-molecular-weight hyaluronic acid or a salt thereof is used to form a compact network structure; the loose structure and the compact network structure are mixed to continue a crosslinking reaction to form a gel having a soft elastic mosaic structure in which loose pores wrap elastic hard spheres; then the gel is mixed with the microspheres, the entry of rigid microspheres in the gel enables the composition to have both a soft elastic function and rigid support performance, and the soft elastic function and the rigid support performance have a synergistic effect; the gel can also effectively protect the microspheres during moist heat sterilization, reducing the degradation of the microspheres, prolonging the effect of the microspheres in stimulating collagen regeneration, making applicable skin layers and sites to be filled more extensive, and improving the safety of the composition in use.

The invention belongs to the field of leukocyte-depleting filters, and particularly relates to a connecting method of a leukocyte-depleting filter and a connecting pipe suitable for moist heat sterilization. The invention aims to solve the technical problem that in the prior art, when a leukocyte-depleted filter is connected with a connecting pipe, due to the difference of thermal expansion coefficients of materials, interface stress concentration and damp-heat aging of an organic adhesive are caused, and then sealing failure, leakage or separation and the like occur after damp-heat sterilization. According to the connecting method for the leukocyte-depleted filter and the connecting pipe suitable for moist heat sterilization, the mechanical reliability of a connecting assembly is remarkably improved through the design of a composite interface of micro-bulge mechanical interlocking and hydrogel chemical bonding.

The invention relates to the field of medical detection, in particular to a fluorescent sensing composition, a fluorescent sensing film and application thereof. According to the invention, by screening a plurality of fluorescent indicators and combinations thereof, an indicator formula with simple components and low cost is finally obtained. Based on the formula, by optimizing the preparation process, the high-efficiency fluorescent sensing film resistant to damp-heat sterilization is developed. After a microorganism culture bottle prepared on the basis of the membrane is inoculated with Gram-negative bacilli, positive cocci and yeast fungi representative quality control strains, experiments of full-automatic microorganism culture system fluorescence curve determination, Gram staining, microorganism mass spectrum identification and the like prove that the fluorescence sensing membrane is excellent in detection performance. The fluorescent sensing film provided by the research is applied to clinical microorganism detection, can provide technical support for blood flow infection diagnosis, and is of great significance in suppressing antibiotic abuse and improving prognosis of blood flow infection patients.

This invention provides a method for preparing rocuronium bromide injection. By optimizing the conventional moist heat sterilization process, specifically by increasing the initial temperature of the heating process and decreasing the initial temperature of the cooling process, the overall exposure time of the injection to high temperatures is significantly shortened while maintaining the sterilization time at 121°C, thus significantly improving the quality stability of rocuronium bromide injection. Multiple batches of samples from this invention have met the related substance limits for rocuronium bromide injection as specified in the Chinese Pharmacopoeia, after accelerated stability and long-term stability studies.

The application provides a preparation method and application of a sterile inhalation suspension containing a PDE-4 or PDE-3 / 4 inhibitor. The preparation method comprises dispersing the PDE-4 or PDE-3 / 4 inhibitor in injection water containing an excipient, high-pressure wet heat sterilization to obtain a PDE-4 or PDE-3 / 4 inhibitor dispersion; further comprising dissolving a long-acting beta2-receptor agonist and / or a long-acting muscarinic receptor antagonist, sterile filtration to obtain a mixed solution; mixing the PDE-4 or PDE-3 / 4 inhibitor dispersion with the mixed solution, dispersing and sterilely filling. The pharmaceutical preparation prepared by the application is a sterile inhalation suspension, the sterile inhalation suspension containing the PDE-4 or PDE-3 / 4 inhibitor has high bioavailability, good patient medication compliance and good preparation stability.

The invention belongs to the technical field of agriculture, and provides an artificial feed and a method for testing the influence of the artificial feed on the growth and development of tomato leaf miners, the method comprises three artificial feed formulas, and standardized feed blocks are prepared through moist heat sterilization and low-temperature preservation. The method comprises the following steps: subpackaging feed by adopting finger-shaped tubes, inoculating according to the density of 3 larvae in each tube, feeding at 25 + / -1 DEG C, and measuring indexes such as the duration, the survival rate, the pupation rate and the eclosion rate of the larvae. Results show that the difference between the formula I and natural foodstuff is minimum, the larva survival rate, pupation rate, pupa weight, eclosion rate and hatching rate are not obviously different from those of natural tomato leaf feeding, and although the larva and pupa duration is prolonged and the single female egg laying amount is reduced, the complete life history of tomato leaf miners can still be supported. According to the method, indoor stable test insects with consistent physiological status are realized, and reliable insect source guarantee is provided for biological research and prevention and control technology development of the tomato leaf miner.

This application provides a sodium hyaluronate gel and its preparation method, belonging to the field of biomedical materials, aiming to solve the problem of severe performance degradation of cross-linked sodium hyaluronate gels during moist heat sterilization. The gel contains cross-linked sodium hyaluronate and is compounded with a solvation shell-building agent and a high-temperature free radical scavenger. These two agents synergistically constitute a dual protection system, jointly protecting the gel structure. The preparation method includes matrix cross-linking, in-situ loading of the protection system through dialysis equilibrium, homogenization, and terminal moist heat sterilization. After moist heat sterilization at 121°C, the gel of this invention exhibits a high storage modulus retention rate, demonstrating excellent thermal stability and synergistic effects, ensuring stable product performance.

A tray laying machine for moist heat sterilization of medicine powder comprises a rack, and a sterilization tray placing device, a sterilization tray conveying device and a charging tray laying device are arranged on the rack. Automatic medicine powder charging and tray laying are achieved through the sterilization tray containing device, the sterilization tray conveying device and the charging and tray laying device, closed conveying and accurate operation are achieved through automatic connection, the links of temporary medicine powder storage and manual scooping are omitted, the medicine powder splashing loss and the microbial contamination risk are remarkably reduced, meanwhile, the charging uniformity and the tray laying efficiency are improved, and the labor intensity of workers is lowered. The labor cost and the labor intensity are reduced, and the large-scale production requirement is met.

The present invention relates to the technical field of polysaccharide material modification, and specifically relates to a high-viscoelastic crosslinked biopolysaccharide gel, a preparation method therefor, and an application thereof. After a carboxyl-group-containing biopolysaccharide and a diaminodiketopiperazine-based crosslinking agent are dissolved and mixed uniformly, a crosslinking reaction is generated under the action of a condensing agent to obtain a high-viscoelastic crosslinked biopolysaccharide gel; following moist heat sterilization, the resulting high-viscoelastic crosslinked biopolysaccharide gel meets conditions for the application thereof, and can be applied to the preparation of injectable formulations, internal filler formulations, or topical pharmaceutical carrier formulations. The crosslinked biopolysaccharide gel prepared according to the present invention exhibits large headroom, in terms of viscoelasticity data, to accommodate moist heat sterilization, which ensures product sterility while guaranteeing the product has good viscoelastic performance, with low cytotoxicity, high product purity, and long service life.

The invention belongs to the field of pharmaceutics, and particularly relates to a composition containing budesonide and formoterol, and the composition provided by the invention is in a specific pH range, adopts a specific surfactant addition mode, also adopts moist heat sterilization, and is free of toxic and side effects. The prepared inhalation suspension of formoterol and budesonide has better delivery rate and total delivery amount, better fine particle fraction and smaller particle size distribution, has the advantages of low temperature, short time, strong penetrating power, economy, rapidness and the like compared with dry heat sterilization and moist heat sterilization, and is more suitable for industrial mass production.

The present application relates to the technical field of microorganism or culture thereof processing, and particularly relates to a method for breeding pleurotus ostreatus mycelium by using highland barley as a substrate. The method is as follows: highland barley is crushed and sieved, then water is added to prepare highland barley slurry, and a complex enzyme system composed of amylase and cellulase is added to perform liquid enzymolysis to obtain an enzymolysis substrate; lactic acid bacteria strains are inoculated into the enzymolysis substrate to perform solid-state fermentation to obtain a fermentation substrate; the fermentation substrate is subjected to moist heat sterilization treatment to obtain a sterilized substrate; the sterilized substrate is inoculated with pleurotus ostreatus original seeds, and is placed in a culture environment for culture to obtain pleurotus ostreatus mycelium. The scheme breaks the physical barrier of the fiber network of the highland barley epidermis and the starch crystal structure of the endosperm by using the complex enzyme system and lactic acid bacteria fermentation, and the substrate is pre-degraded before the mycelium is inoculated, so that the mycelium can directly absorb free carbon sources, the germination time is shortened, the daily growth rate is improved, the residual sugar rate of the substrate is reduced, and the dry weight biomass of the mycelium is increased.

The invention provides a sterilization process of a diillain acetate injection, a to-be-sterilized product is the sterilization of the diillain acetate injection after filling and sealing, the sterilization adopts a moist heat sterilization process, the sterilization temperature is 121 DEG C, the sterilization duration is less than or equal to 1637 seconds, the total sterilization duration is less than or equal to 3201 seconds, and the sterilization heat preservation duration is 12 minutes. The sterilization process is simple and easy to operate, the method is stable, and after sterilization, the key quality attributes (CQAs) such as the content, related substances and sterility of the diillain acetate injection meet strict quality standards after sterilization and in the whole shelf life. The diillain acetate injection prepared by the sterilization process is good in product quality and stability, stable in quality under the condition of 30-day influence factors at the high temperature of 60 DEG C, and in accordance with the drug registration standard.

The application discloses a paraffin-preventing strain compound system for crude oil production, which is composed of Campylobacter, Bacillus and a nutrient formula. The application also discloses a preparation method of the paraffin-preventing strain compound system, which comprises the following steps: 1, weighing each component according to the proportion of the nutrient formula, and mixing uniformly to obtain the nutrient formula; 2, carrying out moist heat sterilization on the nutrient formula to obtain a sterilized mixed solution; 3, cooling the sterilized mixed solution to normal temperature, inoculating the Campylobacter and the Bacillus to obtain a compound sterilized mixed solution; and 4, placing the compound sterilized mixed solution into a constant-temperature biochemical incubator to culture, and the paraffin-preventing strain compound system can be obtained. The paraffin-preventing strain compound system is regularly applied to the annulus of the casing of an oil well, can effectively prevent the deposition of paraffin between the sucker rod and the wellbore, is used for the subsequent microbial paraffin prevention after thermal paraffin removal, has a long action effect period of thermal paraffin removal, does not affect the production time and the oil well production, and meanwhile, the culture medium has low cost, and the paraffin-preventing functional bacteria cultivated are salt-tolerant and acid-alkali resistant.

The invention relates to the technical field of biomedical materials, in particular to polynucleotide / macromolecular protein composite gel capable of tolerating terminal moist heat sterilization as well as a preparation method and application of the polynucleotide / macromolecular protein composite gel. The product provided by the invention is a composite gel of polynucleotide PN and a specific type of high-molecular protein, and under the conditions of a specific ratio and molecular weight, the high-thermal denaturation temperature is higher, and the high-molecular protein with a specific structure has a better protection effect on the polynucleotide PN; the stability and biological activity of polynucleotide PN molecules can be kept under the condition of high-temperature terminal sterilization, the safety of a sterilized product can achieve the effect of thoroughly inactivating viruses, and the filling and supporting properties of the product serving as a stent material are completely reserved; the compound can be directly used in drugs, medical instruments or cosmetics in the field of tissue engineering, and has high safety and lasting effect.

The utility model discloses a connecting piece and a leukocyte-depleted filter composed of the same, and belongs to the technical field of blood separation. The connecting piece comprises a filter connecting pipe and a pipeline connecting pipe which are coaxially connected, the circumferential surface of the filter connecting pipe is an inclined surface, and a threaded area is arranged on the circumferential surface of the filter connecting pipe. The leukocyte-depleting filter comprises a filter body 201 and the connecting piece. Threaded areas are arranged on the inner walls of interfaces at the liquid inlet end and the liquid outlet end of the filter body, the inner walls of the interfaces are inclined planes, and the filter connecting pipe of the connecting piece is inserted into the interfaces and is in threaded connection with the interfaces. According to the application, the leukocyte-depleting filter made of the PP material is connected with the pipeline made of the PVC material through the connecting piece made of the polycarbonate material, and transition is performed through the connecting piece, so that the joint of the connecting piece and the leukocyte-depleting filter as well as the joint of the connecting piece and the pipeline are relatively stable in the damp-heat sterilization process, the phenomenon of separation is avoided, and the yield is increased.

The invention discloses a beclomethasone propionate inhalation suspension and a preparation method thereof, the beclomethasone propionate inhalation suspension comprises the following components in percentage by weight: 0.03%-0.05% of beclomethasone propionate, 0.8%-0.9% of sodium chloride, 0.1%-0.15% of a surfactant and 0.04%-0.06% of disodium hydrogen phosphate, and the percentage is based on the weight of water in the suspension. Buffer salt disodium hydrogen phosphate is added into the prescription composition, so that the generation of impurities is inhibited during moist heat sterilization, the thermal stability of beclomethasone propionate is enhanced, the high-temperature tolerance of the product is improved, and the possibility of moist heat sterilization of beclomethasone propionate suspension is further realized.

According to an embodiment of the present disclosure, the room-temperature stable, unbuffered rocuronium injection formulation for intravenous administration comprises of 1% w / v of rocuronium bromide, a pH adjusting agent comprising hydrochloric acid at a concentration between 12.5 mMol and 20 mMol for the adjustment of pH between 3.5 to 4.5 and a quantity sufficient of water to make the formulation to 1 mL. The proposed formulation of the present disclosure is stabilized through optimization of pH of the formulation using only hydrochloric acid and / or sodium hydroxide as the pH adjusting agents without use of any buffering agents is suitable for moist heat sterilization. Further, the rocuronium injection formulation of the present disclosure contains lower than 3% of rocuronium related compound C, more preferably less than 2% over the stability period at room temperature conditions.

The invention provides a sterilization process of a glucose-containing double-chamber bag blood filtration replacement liquid, a to-be-sterilized product is a filled and sealed blood filtration replacement liquid, the sterilization adopts a moist heat sterilization process, the sterilization temperature is 121 DEG C, the heating time is 1500-3800 s, the sterilization time is 25-30 min, and the cooling time is greater than or equal to 2000 s. The sterilization process is simple and easy to operate, the method is stable, and it is ensured that the content of 5-hydroxymethylfurfural in a blood filtration replacement liquid A chamber is at a low level after sterilization; b, a chamber sterilization exposure stage: 121 DEG C is greater than 12min; the sterile standard level of the obtained glucose-containing double-chamber bag blood filtration replacement liquid reaches the standard within 18 months, the validity period reaches 18 months, and the glucose-containing double-chamber bag blood filtration replacement liquid has very good market circulation and clinical use values.

The invention relates to the technical field of biological medicine, in particular to a glycerin fructose sodium chloride injection and a preparation method thereof, and every 1000 mL of the glycerin fructose sodium chloride injection comprises 80-120 g of glycerin, 40-60 g of fructose, 7-11 g of sodium chloride, 0.6-2.0 g of lecithin, 0.1-0.4 g of organic acid and water for injection. The preparation method comprises the following steps: dispersing lecithin in water for injection at 50-60 DEG C, then adding glycerol, sodium chloride and organic acid, adding fructose after the system is cooled to 40 DEG C or below, finally fixing the volume, adjusting the pH value to 4.0-4.5, and carrying out two-stage filtration and moist heat sterilization. According to the invention, through compounding of lecithin and organic acid, generation of a fructose degradation product 5-hydroxymethylfurfural can be significantly inhibited.

The invention relates to a vacuum plasma treatment device and method for a leukocyte-depleting filter body, and belongs to the technical field of vacuum treatment of leukocyte-depleting filters. Comprising a placing frame assembly, a conveying belt and plasma treatment equipment. The placing frame assembly is placed on the conveying belt, and a connecting port of the liquid inlet end or the liquid outlet end of the leukocyte-depleted filter is vertically arranged upwards. The two ends, in the width direction, of the conveying belt are each provided with a horizontally-arranged bottom linear module, stand columns are fixed to sliding parts of the two bottom linear modules, a top linear module is jointly erected on the tops of the two stand columns, and a sliding part of the top linear module is fixedly connected with a plasma spray head of plasma treatment equipment. And the plasma nozzle is vertically arranged downwards. The liquid inlet port and the liquid outlet port of the leukocyte-depleted filter are modified through the vacuum plasma technology, the bonding strength of the leukocyte-depleted filter and the adhesive interface of the polyvinyl chloride pipeline is remarkably improved, and the hidden danger of interface separation in the moist heat sterilization process is effectively solved.

This invention discloses a system and method for transferring aseptically packaged sterile materials from a non-sterile environment to a sterile environment. The system includes recombinant air intake bags (RABs) and an isolator adjacent to the RABs. The laminar flow hoods of the RABs provide Class A unidirectional flow. Each RAB has a material transfer window at its front end, a waste discharge port on its side, and a rat hole at the connection point between the RABs and the isolator. The laminar flow hoods of the isolator also provide Class A unidirectional flow. The method involves transferring materials with at least one layer of sterile outer packaging through the material transfer window to a designated location within the RABs. Self-cleaning occurs under good Class A unidirectional flow. After self-cleaning, the outer packaging is removed, and the sterile material inside the bag is transferred to the isolator. This invention is suitable for the aseptic transfer of materials that cannot be sterilized by moist heat; it allows for continuous aseptic transfer; and each aseptic transfer is time-efficient.

The invention relates to the field of high polymer materials, in particular to a TPE (thermoplastic elastomer) material resistant to damp-heat sterilization and a preparation method. The elastomer material comprises polypropylene random copolymer, modified graphene, modified montmorillonite, an antioxidant, a slipping agent and white oil, the montmorillonite is modified zinc oxide coated montmorillonite, and the modified graphene is graphene grafted with a fluorine-containing amine-b-quaternary ammonium salt copolymer chain. The TPE material with moist heat sterilization resistance is prepared through common use of the two modified components.

The invention provides a sterilization method for a product containing a marine organism extract, which adopts a moist heat sterilization process, the moist heat sterilization process is carried out by adopting a staged pressure pulse synergistic mode, the sterilization temperature is 120-130 DEG C, and the sterilization time is 9-15 minutes; the product contains sodium alginate, trehalose and other raw materials, an intermediate is prepared through a specific preparation technology, and the intermediate is filled, sealed and sterilized. A bacillus stearothermophilus biological indicator verifies that the sterility guarantee level of a sterilized product is less than or equal to 10 <-6 >, indexes such as pH and heavy metals meet standards, and sodium alginate is stable and is not obviously degraded; the method disclosed by the invention avoids the problems of pungent smell and component degradation of irradiation sterilization, improves the production efficiency and reduces the energy consumption compared with the traditional moist heat sterilization, gives consideration to the sterile effect and the product performance stability, and is suitable for skin care products containing marine organism extracts.

The invention discloses a nano iron oxide injection based on a synergistic stabilization mechanism and a preparation method of the nano iron oxide injection. The injection comprises nano iron oxide particles, carboxyl-terminated methoxypolyethylene glycol, an amino acid stabilizer, a citrate buffer agent and an isotonic agent. The preparation method comprises the following steps: synthesizing an oleic acid modified nano iron oxide core; performing ligand exchange at 0-4 DEG C to form a PEG anchoring layer; then, under the temperature of 6-8 DEG C, through programmed feeding and low-temperature shearing, amino acid and citrate are synergistically embedded, and a stable structure is constructed. According to the invention, a triple stable system of PEG anchoring layer-synergistic chelating layer-buffer microenvironment is constructed, and a whole-course low-temperature controllable process is adopted, so that the defects of poor long-term stability, high iron ion release rate, poor process reproducibility and poor moist heat sterilization resistance of the existing nano iron oxide contrast agent are overcome. The obtained product has excellent colloidal stability, extremely low ion release rate and good biological safety, and is suitable for magnetic resonance imaging.