KR100637275B1 - Preparation of nano size Iron oxide for MRI contrast agent by ultrasonic and manufaturing method thereof and manufaturing method of MRI contrast agent using Iron oxide nano particle and MRI contrast agent thereof - Google Patents

Abstract

The present invention relates to an iron oxide nanopowder used in MRI contrast agent prepared using ultrasonic waves, a method for preparing the same, and a method for preparing the MRI contrast agent using the same, and an MRI contrast agent, the purpose of which is to use an inexpensive iron salt compound, The present invention provides an iron oxide-polysaccharide MRI contrast agent and a method for manufacturing the same, and a method for producing iron oxide nanopowders which can be produced economically and economically.

The constitution of the present invention is to adjust the pH of the mixed solution of ferrous salts and ferric salts in distilled water to 9-12, and then irradiate the mixed solution with ultrasonic waves to provide excellent crystallinity and uniform particle size. Preparing an iron oxide powder; Washing the iron oxide powder prepared in the step to be 6-7 having a neutral pH as deionized tertiary distilled water; 2wt%-5wt% of washed powder The technical features of the iron oxide nanopowder and MRI contrast agent, and the iron oxide nanopowder and MRI contrast agent prepared therefrom comprising the step of dispersing by using ultrasonic waves in a polysaccharide solution.

Iron oxide nano powder, SPIO, USPIO, MRI contrast agent, polysaccharide, oligosaccharide, chitosan, ultrasonic

Description

Iron oxide nanopowder used for MRI contrast agent prepared using ultrasonic wave and its preparation method and preparation method of MRI contrast agent using the same and its MRI contrast agent {Preparation of nano size Iron oxide for MRI contrast agent by ultrasonic and manufaturing method about and manufaturing method of MRI contrast agent using Iron oxide nano particle and MRI contrast agent approximately}             

1 is a photograph of the present invention iron oxide nanopowder electron microscope synthesized using ultrasonic waves,

2 is an X-ray diffraction analysis of the iron oxide synthesized by coprecipitation method and iron oxide of the present invention synthesized by ultrasonic irradiation time,

3 is a magnetic history curve of the iron oxide of the present invention synthesized by ultrasonic irradiation time;

4 is a cluster particle size distribution diagram of the MRI contrast agent (iron oxide-chitosan solution) of the present invention prepared by ultrasonic irradiation time;

5 is a cluster particle size distribution diagram of the present invention MRI contrast agent (iron oxide-chitosan solution) prepared according to the change in the intensity of the ultrasonic wave,

6 is an MRI contrast agent (K-1-K-12) prepared in the present invention for MRI and commercial MRI contrast agent (R-1-R-12) sample photograph,

7 is an MRI T2 * image photograph of the MRI contrast agent (K-1-K-12) and commercial MRI contrast agent (R-1-R-12) samples prepared in the present invention.

The present invention relates to an iron oxide nanopowder that can be used as a diagnostic magnetic resonance imaging (MRI) contrast agent, a method for producing the same using ultrasonic waves, a method for preparing an MRI contrast agent prepared therefrom, and an MRI contrast agent thereof. More specifically, the present invention relates to the preparation of MRI contrast agents using polysaccharides such as glycogen, starch, chitosan, and the like, which are harmless to humans and have immunological activity. This simple and manufacturing time is 1 to 2 hours, and the manufacturing time is extremely short, so that the mass production is possible and the manufacturing method can be made cheaply. (Comparative Patent Publication No. 10-2004-0034224)

Among the methods that can diagnose the disease of the human body by internal observation, MRI is the safest recently developed technology compared to other imaging techniques.

The advantage of MRI is that it is sensitive to tissue and is not exposed to radiation unlike other imaging techniques. As the applicability and availability of MRI is increasing rapidly, the domestic development of MRI contrast agent is urgent.

Types of MRI contrast agents are colloidal solutions using paramagnetic materials such as gadolium (Gd), manganese (Mn), and iron oxide (Fe). Among these paramagnetic materials, gadolium and manganese are very toxic, forming chelates as organics, preventing them from being released.

However, injecting a contrast agent made of gadolium and manganese into a vein diluted with physiological saline or 5% glucose solution. During dilution, the organics of the chelate drop off and the toxic metals can be exposed. In addition, the contrast agent made of gadolium or manganese metal has a very short half-life of about 14 minutes and is rapidly excreted in the urine after administration (Hiroki Yoshikwa et al, Gazpshindan, 6, 959-969, 1986). It is difficult to diagnose distribution, blood flow distribution, distribution amount, permeation, etc. Therefore, in order to obtain a clear image contrast of the MRI between the normal and damaged areas, the length of stay in the body is preferred as an MRI contrast agent.

On the other hand, MRI contrast agents made of iron oxide are non-toxic contrast agents that have already passed the stability test results and can stay in the body for about 8 hours, which is very suitable for accurate diagnosis of MRI. Nevertheless, in the iron oxide nano powder and its manufacturing method (Patent 10-2004-0034224), the production temperature and time are too high and long, such as iron oxide production temperature is synthesized at more than 286 ℃ and oxidized for 1 day-7 days. In addition, the raw material for manufacturing iron oxide was Fe (CO) _{5 which} is very expensive and difficult to store.

On the other hand, the synthesis of magnetite nanoparticles and the manufacturing method of Fe-based nanomaterials (patent 2003-0082394) synthesized iron oxide or ferrite at a temperature of 200 ℃-360 ℃ like a mixture of an organic solvent and an amine. As such, the manufacturing temperature of the iron oxide nano powder is high and the process is not simple. In other words, although there is a domestic patent on a method for manufacturing medical iron oxide nanopowder, the process is not only complicated or expensive to use, but there is no domestic development of MRI contrast agent from the manufactured iron oxide nanopowder.

Furthermore, although the MRI contrast agent prepared from dextran from iron oxide nanopowders is foreign, patents for developing MRI contrast agents using polysaccharides such as chitosan, which are biocompatible compounds, have not been registered.

An object of the present invention for solving the above problems is to use a low-cost iron salt compound, the process time is less than 2 hours at room temperature and the manufacturing method of the iron oxide nano powder is short and the process is simple and iron oxide nanoparticles produced therefrom The present invention provides an iron oxide-polysaccharide colloidal solution, that is, an MRI contrast agent and a method for producing the same, which can be mass-produced and economically produced using powder.

The present invention to achieve the object as described above and to perform the problem for removing the conventional defects is a method for producing iron oxide nanopowder that can be used as diagnostic nuclear magnetic resonance imaging (MRI) contrast medium using ultrasound And a method for producing a contrast agent using the iron oxide nanopowder produced and the contrast agent produced therefrom.

In the above, iron oxide has superparamagnetism (SPIO or USPIO) as Fe ₂ O ₃ or Fe ₃ O ₄ in the range of 2 nm to 20 nm, and the polysaccharide uses one or more selected from chitosan, starch, oligosaccharide, and dextran. Among them, chitosan is a natural polymer polysaccharide extracted from shells of shellfish such as crabs or shrimps.

Referring to the manufacturing method of the present invention step by step as follows.

First, the method for preparing iron oxide nanopowder is adjusted to pH 9-12 with NaOH or ammonia water in a mixed solution of ferrous and ferric salts in distilled water, and then the mixed solution is irradiated with ultrasonic waves for excellent crystallinity and particle size. Preparing an iron oxide powder which is a nano magnetic powder in a uniform range of 2 nm to 20 nm;

The iron oxide powder prepared in the above step is washed with a deionized tertiary distilled water so as to have a pH of 6 to 7 being neutral.

Thereafter, the step of preparing the MRI contrast agent is to disperse the washed powder in a solution of 2wt%-5wt% polysaccharides (chitosan, starch, oligosaccharides, dextran, etc.) using ultrasonic waves to prepare an MRI contrast agent which is an iron oxide-polysaccharide solution. ;

Thereafter, the step of purifying the contrast agent is a step of purifying by centrifugation for 10-20 minutes at 3000G ~ 5000G to remove the clusters formed by the iron oxide particles in the iron oxide-polysaccharide colloid solution (MRI contrast agent) prepared by agglomeration with each other Wow;

After sterilization at 110 ℃ for 30 minutes to complete the preparation of the MRI contrast agent, including all steps to prepare the MRI contrast medium.

Hereinafter, the overall manufacturing method of the present invention will be described in detail, but the polysaccharide will be described with chitosan for convenience.

Inexpensive ferric oxide (FeCl ₂ · 4H ₂ O) and ferric salt (FeCl ₃ · 6H ₂ O) in an aqueous solution mixed with distilled water in a 1: 2 equivalent ratio to adjust the pH to a range of 9-12 with NaOH or NH ₄ OH. The ultrasound is then irradiated for 10-30 minutes.

At this time, since the iron salt has a high solubility, it only needs to be melted so that a proportion of distilled water is not required. In addition, the pH range 9-12 is a general pH range in which iron oxide is produced. In addition, the reason for limiting the irradiation time of the ultrasonic wave was the optimum time during the experiment. Less than 10 minutes was not suitable for nanoparticle production, such as nanoparticle production was incomplete and particles became smaller again after 30 minutes.

After the ultrasonic irradiation, black nano-sized iron oxide (SPIO or USPIO) is precipitated. At this time, the supernatant is discarded and the precipitated iron oxide powder is washed as third distilled water until the pH of the washing solution is 6-7. The reason for limiting the pH to 6-7 is because the MRI contrast agent should be injected into the human body, so it should be in the neutral range of 6-7.

The washed iron oxide powder is put in 10 ~ 20ml in 1wt% ~ 5wt% chitosan solution and again irradiated with ultrasonic waves for 10-20 minutes. The reason for limiting the irradiation time is that it is the best time for dispersion to occur during the experiment.

In doing so, most of the iron oxide is stably dispersed in the chitosan solution, but the chitosan colloidal solution is still purified from the centrifuge at 3000G to 5000G for 10-20 minutes to use only the supernatant as the MRI contrast agent. It is because it is refined to the most optimal particle when it is limited to such a value.

The prepared MRI contrast agent was placed in a sterilized container and sterilized again at 110 ° C. for 30 minutes. Such numerical conditions are generally known sterilization conditions.

Hereinafter, the configuration and the operation of the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an electron micrograph of the present invention the iron oxide nano powder synthesized using ultrasonic waves, Figure 2 is an X-ray diffraction analysis of the iron oxide synthesized by the co-precipitation method of the present invention iron oxide synthesized by ultrasonic irradiation hour, Figure 3 is ultrasonic irradiation Magnetic hysteresis curve diagram of the iron oxide of the present invention synthesized over time, Figure 4 is a cluster particle size distribution of the MRI contrast agent (iron oxide-chitosan solution) prepared according to the ultrasonic irradiation time, Figure 5 is the MRI contrast agent of the present invention prepared according to the change in ultrasonic intensity Cluster particle size distribution of (iron oxide-chitosan solution), Figure 6 is a photograph of the MRI contrast agent (K-1-K-12) and commercial MRI contrast agent (R-1-R-12) prepared in the present invention for MRI imaging 7 is an MRI T2 image photograph of an MRI contrast agent (K-1-K-12) and a commercial MRI contrast agent (R-1-R-12) sample prepared in the present invention.

(Example 1)

Nano sized iron oxide synthesis

2.43 g of ferric chloride (FeCl ₃ · 6H ₂ O) and 0.99 g of ferrous chloride (FeCl ₂ · 4H ₂ O) were dissolved in 80 ml of distilled water, and 6 ml of ammonia was added. The solution was irradiated for 30 minutes by ultrasonic (20 Hz). The precipitate obtained after sonication is washed several times with distilled water so that the filtrate pH of the last wash is 6-7. The precipitate obtained at this time is black and the electron micrograph is as shown in Figure 1, the particle shape is very uniform in a circular shape, the size is average 9.8nm.

(Example 2)

Crystallization and Magnetic Properties of Iron Oxide Nanopowders Synthesized by Ultrasonic Irradiation Time

X-ray diffraction analysis of each precipitate obtained by changing the irradiation time in the experiment of Example 1 to 15 minutes, 30 minutes, 60 minutes and the precipitate obtained by the commonly known coprecipitation method is as shown in FIG. As shown in FIG. 2, all the precipitates are iron oxide, and the crystal is magnetite (Fe ₃ O ₄ ), and the X-ray diffraction peak intensity is larger when ultrasonic waves are irradiated than iron oxide obtained by the coprecipitation method. This shows excellent crystallinity. In addition, the magnetic properties of the iron oxide obtained by ultrasonic irradiation time was measured as a vibration sample magnetometer (Vibrating Sample Magnetometer) bar bar as shown in FIG. Since all of the iron oxides synthesized in Example 2 exhibited superparamagnetism, they were suitably used as MRI contrast agents, and as the ultrasonic irradiation time increased, the magnetization value decreased. This is because the particle size becomes small even if the time becomes too long.

(Example 3)

Preparation of Iron Oxide-polysaccharide Colloid Solution from Synthetic Iron Oxide Powder

When the synthesized iron oxide nanopowder enters the human body at 10 nm or less, it is spread throughout the body by macrophages in blood vessels or excreted in the kidneys. Therefore, when nanoparticles of 10 nm are dispersed in an aqueous polysaccharide solution, several magnetic iron oxide nanopowders are clustered together. In particular, the cluster size suitable for use as a liver specific contrast medium is about 70 nm to 80 nm.

Therefore, 16 ml of chitosan aqueous solution, which is one of 1% polysaccharides, was added to the nano magnetic powder synthesized in Example 2, and the colloidal solution was prepared by irradiating for 15 minutes, 30 minutes, and 60 minutes at 30% output of a 20 Hz ultrasonic device.

Each colloidal solution was measured using a dynamic razor particle size analyzer to measure the cluster size of particles in the chitosan solution. Ultrasonic irradiation resulted in a cluster size distribution ranging from 100 nm or less to hundreds of nm for 15 and 30 minutes, but ultrasonic irradiation resulted in a relatively uniform particle distribution with an average of 96 nm for 60 minutes.

In addition, by changing the output of the ultrasonic wave to 20%, 30%, 35% and 40% to measure the cluster size as the ultrasonic irradiation time, as shown in FIG. When the ultrasonic output was 20% or 40%, the cluster size distribution was narrowest from 50 nm to 90 nm when the cluster size distribution was 30%, and the average cluster size was 72 nm. Therefore, when the irradiation time is 60 minutes and the output power is 30%, the cluster size is uniform and the average size is 72 nm, which is an appropriate size as a liver specific contrast medium among MRI contrast agents.

For reference, 80-90% of the macrophage (reticular endothelial cells), the cell population responsible for the human body's defense function, are called liver cells, and in particular, it is called Kupper cell. It is because it is 60-100 nm.

(Example 4)

MRI T2 Image According to the Change of Magnetic Powder Concentration (Fe)

In Example 3, the concentration of nano magnetic powder was adjusted from 0.417 mmol to 7 * 10 ⁻⁶ mmol to change 12 different iron (Fe) concentrations to prepare MRI contrast agents.

This contrast agent is effective for obtaining T2 image as a liver-specific contrast agent, and the result of comparing T2 image by changing iron concentration with a commercial product is shown in Table 1 and FIGS. 6 and 7. Table 1 shows the iron concentrations of the MRI contrast agent (K-1-K12) and the commercial product (R-1-R12) prepared in the examples. Figure 6 is a sample photograph for measuring the MRI of the MRI contrast agent and the commercial MRI contrast agent prepared in the present invention. 7 is a T2 image obtained as Phillips MRI 3 Tesla. As a result, although the iron concentration of the commercial contrast medium is 20-30% higher than the iron concentration of the MRI contrast agent prepared in this embodiment, it can be seen that the degree of contrast of the MRI T2 image is not high.

Table 1 Iron Concentrations of MRI Contrast Agents Prepared from Example 4 and Commercial MRI Contrast Agents

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

The present invention as described above can be made inexpensive by using a general iron compound, in particular, since the manufacturing method can be produced simply and quickly at room temperature, it is possible to mass-produce in a short time, and can produce nano magnetic powder economically. There is this.

In addition, the synthesized nano magnetic powder can be rapidly dispersed by using ultrasonic waves in chitosan solution, which is one of the hydrophilic, non-toxic and safe polysaccharides, and can be used as MRI contrast agent, especially MRI T2 image as liver specific contrast agent. Compared to the concentration of a commercial product, there is an advantage that a more effective image contrast can be obtained.

Therefore, it is a useful invention that not only brings the effect of import substitution of MRI contrast agent which is imported all over Korea, but also shows the enhanced clarity of MRI even if the dose is lower than commercial contrast agent, and can be used safely and efficiently for human body. It is an invention that is expected to be greatly used in the industry.

Claims (10)

delete delete In the manufacturing method of the iron oxide nano powder used in MRI contrast agent, The mixed solution of ferrous and ferric salts dissolved in distilled water was selected from NaOH or ammonia water, and the pH was adjusted to 9-12. The mixed solution was irradiated with ultrasonic waves to provide excellent crystallinity and uniform particle size. Preparing an iron oxide powder; The method for producing iron oxide nanopowders used in MRI contrast agents using ultrasonic waves, characterized in that the step consisting of washing the iron oxide powder prepared in the step so that the pH is neutral 6-7 as deionized tertiary distilled water. The method of claim 3 The size of the iron oxide powder of the nano magnetic powder in the uniform range is 2nm-20nm method for producing iron oxide nanopowders used in the MRI contrast agent using ultrasonic waves. Iron oxide nanopowder used in MRI contrast agent using ultrasonic waves, characterized in that the iron oxide nanopowder prepared according to any one of the method of claim 3 or 4. delete delete In the manufacturing method of the MRI contrast agent using iron oxide nano powder, The mixed solution of ferrous and ferric salts dissolved in distilled water was adjusted to pH 9-12 with NaOH or ammonia water, and the mixed solution was irradiated with ultrasonic waves to provide excellent crystallinity and uniform particle size. Preparing an iron oxide powder in the range of nano magnetic powder; Washing the prepared iron oxide powder as deionized tertiary distilled water to a neutral pH of 6-7; and dispersing the iron oxide nanopowder prepared by ultrasonication in 2wt% -5wt% polysaccharide solution using MRI contrast agent iron oxide- To prepare a polysaccharide colloidal solution, wherein the polysaccharide is chitosan, starch, oligosaccharides, dextran, MRI contrast agent using the iron oxide nano-powder prepared using ultrasonic waves, characterized in that at least one selected from the group consisting of. The method of claim 8, Purifying the clusters by centrifugation for 10-20 minutes at 3000G to 5000G to homogenize the cluster particle size in the iron oxide-polysaccharide colloidal solution; After the sterilization step further comprises the step of producing an MRI contrast agent, characterized in that the manufacturing method of the MRI contrast agent using the iron oxide nano-powder prepared using ultrasonic waves. MRI contrast agent using the iron oxide nanopowder prepared using ultrasonic waves, characterized in that the manufacturing method of the MRI contrast agent according to any one of claims 8 or 9.

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