CN108392642B

CN108392642B - Gadolinium oxide-containing nanoparticle magnetic resonance imaging contrast agent and preparation method and application thereof

Info

Publication number: CN108392642B
Application number: CN201810154654.8A
Authority: CN
Inventors: 陈小元; 沈折玉
Original assignee: Shamu Shanghai Biotechnology Co ltd
Current assignee: Suzhou zeci Medical Technology Co.,Ltd.
Priority date: 2018-02-23
Filing date: 2018-02-23
Publication date: 2020-10-09
Anticipated expiration: 2038-02-23
Also published as: CN108392642A

Abstract

The invention relates to a nano particle containing gadolinium oxide, wherein the inner core of the nano particle is nano gadolinium oxide, and the surface of the inner core is coated with a hydrophilic high molecular compound; the hydrophilic polymer compound is a polymer compound containing a plurality of carboxyl groups or a plurality of amino groups. The invention also provides a composite nanoparticle containing gadolinium oxide, which is formed by compounding the nanoparticle containing gadolinium oxide with other nanoparticles, wherein the outer layer of the other nanoparticles is wrapped by a hydrophilic high molecular compound, and the inner core is any one of iron oxide nanoparticles, manganese oxide nanoparticles, gold nanoparticles, mesoporous silicon nanoparticles or albumin nanoparticles. The gadolinium oxide-containing nano particles and composite nano particles have good aqueous phase dispersibility, stability and biocompatibility and have ultrahigh r₁Value and ultra-low r₂/r₁Ratio, T usable for magnetic resonance imaging₁A contrast agent. The invention also provides a method for preparing the nano particles by an aqueous phase method.

Description

Gadolinium oxide-containing nanoparticle magnetic resonance imaging contrast agent and preparation method and application thereof

Technical Field

The invention relates to a magnetic resonance imaging contrast agent, in particular to a nano material for magnetic resonance imaging, and especially relates to a gadolinium oxide-containing nano particle.

Technical Field

Malignant tumors (cancers) are a common disease seriously harming human life and health, and have become the first cause of death in some countries or regions, and have become the second cause of death after cardiovascular diseases in developed countries. The rapid development of Chinese economy inevitably brings environmental pollution problems in recent years, and especially the increase of the concentration of fine particulate matters (PM2.5) in the atmosphere may cause the increase of the prevalence rate of lung cancer. Therefore, early diagnosis and nontoxic chemotherapy of lung cancer are very important and urgent for the present Chinese society.

Early diagnosis is well recognized as a key to saving the life of tumor patients, however, malignant tumors lack obvious symptoms at an early stage and are found in most cases to be in a middle-advanced stage. As taught by professor Bruce j. hillman of the ACRIN originator of the NCI clinical trial collaboration group, the radiology department of the university of virginia, the conventional clinical diagnosis methods have difficulty in achieving effective early diagnosis of tumors, such as: magnetic Resonance Imaging (MRI), X-ray computed tomography imaging (CT), positron emission computed tomography imaging (PET), and the like. Therefore, the development of an early diagnosis method of the tumor has important scientific significance and wide application prospect. Currently, MRI is one of the major means for diagnosing various types of malignant tumors. However, MRI has limited sensitivity for detecting tumors, and requires the use of contrast agents to improve its detection sensitivity and spatial resolution. Therefore, to realize early diagnosis of various tumors, development of various MRI contrast agents is required.

MRI contrast agents can be largely divided into two main classes: one is T₁Weighted MRI contrast agents, which shorten the longitudinal relaxation time of water protons, such as gadolinium chelates, etc.; another class is T₂Weighted MRI contrast agents that shorten the transverse relaxation time of water protons, such as Magnetic Iron Oxide Nanoparticles (MIONs), and the like.

Since iron is an essential element of the human body, Magnetic Iron Oxide Nanoparticles (MIONs) have relatively good biocompatibility. Thus, MIONs have attracted considerable attention as MRI contrast materials. However, these MIONs-based T₂Contrast agents also have a number of disadvantages: 1) t is₂Dark images of contrast agents may be confused with signals under certain conditions, such as bleeding, calcification and deposition of metals such as endogenous iron; 2) t is₂High magnetic moment of contrast agentMay lead to magnetically sensitive artifacts (i.e. distortion of the magnetic field or background around the diseased region), leading to image blurring; 3) t is₂The time required for imaging is far longer than T₁Imaging; 4) MIONs base T₂The large size of the contrast agent (60-180 nm) results in long clearance times in vivo (typically taking weeks or months) and may lead to long-term chronic side effects. Because of these disadvantages, MIONs-based T is already on the market₂Contrast agents are difficult to market, so that they are withdrawn from the market (e.g.:

and

) Currently, only one MIONs-based T₂Contrast agents (i.e.

) Are still on sale in a few countries, such as the united states and japan.

The MIONs group T₂The disadvantage of contrast agents arises from T₂Imaging and its larger size, to overcome these disadvantages, Taupitz et al first found that MIONs smaller than 5nm had T₁Contrast effect, longitudinal relaxation rate (r) thereof₁) Greater than 2mM^-1s^-1And r is₂/r₁Ratio less than 5 (r)₂Transverse relaxation rate). MIONs smaller than 5nm are called very small magnetic iron oxide nanoparticles (ES-MIONs) and have been extensively studied in recent years. At present, thermal decomposition method, polyol method, coprecipitation method and reductive coprecipitation method have been developed for the synthesis of ES-MIONs. However, r of ES-MIONs₁Not high (<10mM^-1s^-1) And r is₂/r₁Value of not low (>2) This is not favorable for T₁And (6) imaging.

Currently, the MRI contrast agents in widespread clinical use are gadolinium chelates, such as gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) developed by Schering AG, Germany, and gadolinium-1, 4,7, 10-tetraazacyclododecane-1, 4,7, 10-tetraacetic acid (Gd-DOTA) developed by Guerbet SA, Fancisco. Although gadolinium chelates dominate the current MRI contrast agent market, studies have shown that gadolinium chelates have some nephrotoxicity, for which the united states Food and Drug Administration (FDA) has issued formal warnings against all gadolinium chelate contrast agents, suggesting that all patients with renal insufficiency do not.

Increasing r of gadolinium-based MRI contrast agents to reduce nephrotoxicity₁Value and decrease r₂/r₁The ratio becomes critical because of the high r₁Value and low r₂/r₁The ratio can lead to better T₁The imaging effect (i.e. higher Δ SNR value) and thus the dose of gadolinium-based MRI contrast agent. The SNR value is a signal-to-noise ratio (SNR), the Δ SNR is a signal enhancement percentage, and the calculation formula is as follows:

at present, r dominates gadolinium chelates of the current MRI contrast agent market₁The value was lower, about 4mM^-1s^-1. To further increase r₁The value, gadolinium oxide nanoparticles (GdON), has been extensively studied, and r of GdON has been reported₁The value is 4.4 to 47.2mM^-1s^-1，r₂/r₁The ratio is 1.1-6.8. r is₁The value was 47.2mM^-1s^-1R of GdON₂/r₁The ratio is 1.7(1.4T magnetic field), the synthesis method is thermal decomposition method (oil phase method), and the common problem of the oil phase method is that the obtained nanoparticles have poor aqueous phase dispersibility.

According to the analysis of the current research situation of the MRI contrast agent at home and abroad, the prepared MRI contrast agent has good water phase dispersibility, stability and biocompatibility and higher r₁Sum of values r and lower₂/r₁T of the ratio₁Contrast agents are the main trend in research.

Disclosure of Invention

The invention provides a magnetic resonance contrast agent based on gadolinium oxide nanoparticles or gadolinium oxide composite nanoparticles and a preparation method thereofThe magnetic resonance contrast agent has good aqueous phase dispersibility, stability and biocompatibility, and has ultrahigh r₁Value (>50mM^-1s^-1) And ultra-low r₂/r₁Ratio (<1.1) T usable for magnetic resonance imaging₁A contrast agent.

The scheme of the invention comprises the following steps:

firstly, providing a nano-particle containing gadolinium oxide, wherein the inner core of the nano-particle is nano-gadolinium oxide, and the surface of the inner core is coated with a hydrophilic high molecular compound; the hydrophilic polymer compound may be a polymer compound containing a plurality of carboxyl groups or a plurality of amino groups; preferably one or more of polyacrylic acid (PAA), polyglutamic acid, polyaspartic acid, sodium alginate, Polylysine (PLL) and chitosan; polyacrylic acid is most preferred.

In a preferable scheme of the invention, the gadolinium oxide-containing nanoparticles are obtained by adding a gadolinium ion solution into a hydrophilic polymer solution, and stirring and reacting for more than 10 minutes at 60-100 ℃ in the presence of an alkali liquor.

The gadolinium oxide-containing nano particles have smaller sizes, and the particle size is less than 5 nm; the water phase dispersibility, the stability and the biocompatibility are good; with ultra-high r for magnetic resonance imaging₁Value (greater than 50mM)^-1s^-1) And ultra-low r₂/r₁Ratio (less than 1.1); embodying good T₁Contrast effect, can be regarded as T₁Contrast agents are used in magnetic resonance imaging.

The invention also provides a method for preparing the gadolinium oxide-containing nano particles, which mainly comprises the following steps:

(1) preparing a hydrophilic macromolecular compound solution, and deoxidizing for later use;

(2) heating the solution prepared in the step (1) to 60-100 ℃, adding a gadolinium ion solution and an alkali solution, and stirring for reacting for more than 10 minutes; thus obtaining the gadolinium oxide-containing nano particles.

The hydrophilic polymer compound in the step (1) needs to contain a plurality of carboxyl groups or a plurality of amino groups, has good water solubility, and can be any one or a mixture of more than two of polyacrylic acid (PAA), polyglutamic acid, polyaspartic acid, sodium alginate, Polylysine (PLL) and chitosan; preferably polyacrylic acid (PAA), polyglutamic acid or polyaspartic acid; polyacrylic acid (PAA) is most preferred.

The concentration of the hydrophilic polymer compound solution in the step (1) is 0.5-50 mg/mL, preferably 2.0-10 mg/mL, and most preferably 4.0 mg/mL.

The oxygen removal in step (1) is preferably accomplished by nitrogen bubbling or freeze vacuum.

In the step (2), the gadolinium ion solution is preferably any one solution or a mixed solution of more than two solutions of gadolinium chloride, gadolinium nitrate, gadolinium fluoride or gadolinium bromide; more preferably a gadolinium chloride or nitrate solution.

The concentration of the gadolinium ion solution in the step (2) is 30-1000 mM, preferably 100-300 mM, and most preferably 125 mM.

The alkali solution in the step (2) is preferably selected from one or a mixed solution of more than two of ammonia water, sodium hydroxide or potassium hydroxide solution.

In a further preferred scheme, the concentration of the ammonia water is 2-28%, more preferably 20-28%, and most preferably 28%.

In a further preferred embodiment, the concentration of the sodium hydroxide or potassium hydroxide is 0.05-5.0M, more preferably 0.5-2.0M, and most preferably 1.0M.

The volume ratio of the polymer solution to the gadolinium ion solution in the step (2) is 500-5.0, preferably 100-25, and most preferably 50.

The volume ratio of the alkali solution to the gadolinium ion solution in the step (2) is 0.1-100, preferably 2-15, and most preferably 7.5.

The stirring in step (2) may be magnetic stirring or mechanical stirring.

The reaction time in the step (2) needs to be more than 10 minutes, preferably 30-120 minutes, and most preferably 60 minutes.

Preferably, the step (2) further comprises a purification process for removing unreacted polymer and gadolinium ions, and the purification process may be any one or more of dialysis, filtration, centrifugation or chromatography.

The method for preparing the gadolinium oxide-containing nano particles is an aqueous phase method, and the prepared nano particles have ideal water dispersibility.

On the basis, the invention further provides a gadolinium oxide-containing composite nanoparticle, which is formed by compounding the gadolinium oxide-containing nanoparticle and other nanoparticles, wherein the outer layer of each other nanoparticle is coated with a hydrophilic high molecular compound, and the inner core is any one of iron oxide nanoparticles, manganese oxide nanoparticles, gold nanoparticles, mesoporous silicon nanoparticles or albumin nanoparticles.

In the gadolinium oxide-containing composite nanoparticles, the gadolinium oxide-containing nanoparticles can be coated on the surfaces of other nanoparticles in a coupling or in-situ synthesis manner, and can also be coated inside the other nanoparticles; the particle size of the finally formed composite nano particles containing gadolinium oxide is less than 100 nm; the water phase dispersibility, the stability and the biocompatibility are good; has an ultra-high r₁Value (greater than 50mM)^-1s^-1) And ultra-low r₂/r₁Ratio (less than 1.1); has good T₁Contrast effect, can be regarded as T₁Contrast agents are used in magnetic resonance imaging.

The preparation principle of the gadolinium oxide-containing composite nanoparticles mainly comprises the following steps:

(1) the other nanoparticles are prepared according to the method for preparing the gadolinium oxide-containing nanoparticles of the present invention, such as: iron oxide nanoparticles, manganese oxide nanoparticles, gold nanoparticles, mesoporous silicon nanoparticles, and albumin nanoparticles; then in-situ synthesizing the gadolinium oxide-containing nanoparticles on the surface of the gadolinium oxide-containing nanoparticles; thereby preparing the gadolinium oxide-containing composite nanoparticles, namely gadolinium oxide-ferric oxide composite nanoparticles, gadolinium oxide-manganese oxide composite nanoparticles, gadolinium oxide-gold composite nanoparticles, gadolinium oxide-mesoporous silicon composite nanoparticles or gadolinium oxide-albumin composite nanoparticles.

(2) The other nanoparticles are prepared according to the method for preparing the gadolinium oxide-containing nanoparticles of the present invention, such as: iron oxide nanoparticles, manganese oxide nanoparticles, gold nanoparticles, mesoporous silicon nanoparticles, and albumin nanoparticles; then coupling the gadolinium oxide-containing nanoparticles on the surface thereof; thereby preparing the gadolinium oxide-containing composite nanoparticles, namely gadolinium oxide-ferric oxide composite nanoparticles, gadolinium oxide-manganese oxide composite nanoparticles, gadolinium oxide-gold composite nanoparticles, gadolinium oxide-mesoporous silicon composite nanoparticles or gadolinium oxide-albumin composite nanoparticles.

(3) The method for preparing the gadolinium oxide-containing nano particles according to the invention is as follows: mesoporous silicon nanoparticles and albumin nanoparticles; then wrapping the gadolinium oxide-containing nanoparticles with the other nanoparticles; thereby preparing the gadolinium oxide-containing composite nanoparticles, namely gadolinium oxide-mesoporous silicon composite nanoparticles or gadolinium oxide-albumin composite nanoparticles.

The invention also provides application of the gadolinium oxide-containing nanoparticles and gadolinium oxide-containing composite nanoparticles in preparation of magnetic resonance imaging contrast agents.

In the prior art, r is reported in the literature₁The value was 47.2mM^-1s^-1Of gadolinium oxide nanoparticles₂/r₁The ratio r is 1.7₂/r₁Large ratio, influence T₁Imaging effect; in addition, the oil phase synthesis method (i.e., thermal decomposition method) thereof results in poor aqueous phase dispersibility of the resulting nanoparticles, thereby limiting their in vivo applications. When the gadolinium oxide-containing nanoparticles or gadolinium oxide-containing composite nanoparticles provided by the invention are used as a magnetic resonance imaging contrast agent, the gadolinium oxide-containing nanoparticles or gadolinium oxide-containing composite nanoparticles have good aqueous phase dispersibility, stability and biocompatibility, and have ultrahigh r₁Value (greater than 50mM)^-1s^-1) And ultra-low r₂/r₁The ratio (less than 1.1) meets all the requirements of in vivo application. Its ultra-high r₁The value is derived from the ultra-small particle size and ultra-hydrophilic surface, and the ultra-low r₂/r₁The ratio is due to its ultra-small saturation magnetization.

Drawings

FIGS. 1 and 2 are both prepared as in example 1GdON5, Marangju display as a commercial product

And T of pure water₁The MRI images are weighted. Wherein TR is 250ms in fig. 1; TE is 10 ms; TR in fig. 2 is 100 ms; TE is 10 ms.

FIG. 3 is a graph showing the relative MRI signal intensities of GdON5, Magneviras and pure water in FIGS. 1 and 2; p < 0.001.

FIG. 4 shows a Transmission Electron Microscope (TEM) photograph and a high-resolution transmission electron microscope (HR-TEM) photograph of GdON1-5 prepared in example 1.

Fig. 5-7 are particle size distribution, energy dispersive X-ray spectroscopy (EDS) and magnetic field dependent magnetization curves of GdON3, GdON5, respectively, for GdON5 prepared in example 1.

FIG. 8 is a Scanning Transmission Electron Microscope (STEM) image of FeGd-HN1(a), FeGd-HN3(b), and FeGd-HN6(c) prepared in example 2.

FIG. 9 shows the characterization results of Electron Energy Loss Spectroscopy (EELS) corresponding to FIG. 8.

FIGS. 10-13 show the characterization results of FeGd-HN3 and FeGd-HN3-RGD2 prepared in example 2. Wherein (a) and (b) in FIG. 10 are HR-TEM photographs of FeGd-HN3 and FeGd-HN3-RGD2, respectively; FIG. 11 is FeGd-HN3 (d) measured by DLS_h6.5nm) and FeGd-HN3-RGD2 (d)_h8.5 nm); FIG. 12 is an energy dispersive X-ray Spectroscopy (EDS) of FeGd-HN 3; FIG. 13 shows the magnetic field dependent magnetization curves of FeGd-HN3 and FeGd-HN3-RGD 2.

FIG. 14 shows in vivo T-cells of U-87MG tumor-bearing mice following tail vein injection of Magnevist (Magnevist), FeGd-HN3 or FeGd-HN3-RGD2 prepared in example 2₁Weighted magnetic resonance imaging.

FIG. 15 shows the quantitative analysis of tumor signal enhancement in U-87MG tumor-bearing mice after tail vein injection of Magnevist (Magnevist), FeGd-HN3 or FeGd-HN3-RGD2 prepared in example 2.

Detailed Description

The present invention is further described below by way of specific examples, but the present invention is not limited thereto.

Example 1

Preparation of gadolinium oxide nanoparticles (GdON)

40mL of a polyacrylic acid solution (molecular weight: 1800) was prepared at a concentration of 4.0 mg/mL. Nitrogen was bubbled for 50 minutes (deoxygenated) and the solution was heated to 100 ℃. 0.8mL of gadolinium nitrate solution (62.5 to 1000mM) was added through a syringe, followed immediately by 6.0mL of aqueous ammonia solution (28%), and the reaction was carried out for 60 minutes with magnetic stirring. Cooling to room temperature, purifying by dialysis (molecular weight cut-off of 6-8kDa), and concentrating by ultrafiltration (molecular weight cut-off of 3kDa) to obtain GdON. 1000,750,500,250,125, and the nano particles prepared by 62.5mM gadolinium nitrate solution are GdON1-6 respectively, and the relevant synthesis conditions and the characterization results are shown in Table 1.

TABLE 1 Synthesis conditions of GdON nanoparticles and characterization results thereof

^aThe concentrations of gadolinium nitrate, PAA and ammonia water as reactants;

^bthe gadolinium content in the nano particles accounts for the mole percentage of the raw material gadolinium.

Samples GdON2, GdON3, GdON5 and a commercially available MRI contrast agent Magnevist (i.e., Magnevist) prepared in this example were taken as MRI contrast agents to measure T₁Relaxation Rate (1/T)₁) And T₂Relaxation Rate (1/T)₂) Wherein, three samples GdON2, GdON3 and GdON5 of the present embodiment are measured from three batches of synthesized products under the same conditions, respectively; magnevist takes three different bottled products for measurement; the magnetic field used for the measurement was 1.5T. According to T₁Relaxation Rate and T₂Relaxation Rate with gadolinium concentration (C)_Gd) The change of (a) is used for calculating the slope of the change of (b), namely r₁And r₂The value is obtained. The results show that the average r of samples GdON2, GdON3, and GdON5 prepared in this example₁The values are 54.2 + -3.0, 60.7 + -1.9, 70.2 + -1.8 mM respectively^-1s^-1Are all far higher than the average r of the horse root vitamin display₁Values (4.20. + -. 0.16 mM)^-1s^-1). Wherein the average r of GdON3 and GdON5₂/r₁The ratio is 1.03 +/-0.02 and 1.02 +/-0.03 respectively, which are lower than the average value of the root of MarsdeniaAll r₂/r₁Ratio (1.08. + -. 0.06).

FIG. 1 and FIG. 2 show GdON5, a commercially available product, Magen Vickers

And T of pure water₁Weighted MRI images (magnetic field 7.0T). Wherein TR is 250ms in fig. 1; TE is 10 ms; TR in fig. 2 is 100 ms; TE is 10 ms. FIG. 3 is a graph showing the relative MRI signal intensities of GdON5, Magneviras and pure water in FIGS. 1 and 2; p<0.001. The results show that the MRI signal intensity of GdON5 is much higher than that of the Magroot display. These experimental results show that sample GdON5 is a superior T compared to Magen Virginia₁A contrast agent.

FIG. 4 shows a Transmission Electron Microscope (TEM) photograph and a high-resolution transmission electron microscope (HR-TEM) photograph of a sample GdON 1-5. Wherein FIGS. 4(a) -4 (e) are Transmission Electron Microscope (TEM) photographs of GdON1-5, respectively. FIG. 4(f) is a high-resolution transmission electron microscope (HR-TEM) photograph of GdON 5.

Fig. 5-7 are particle size distribution, energy dispersive X-ray spectroscopy (EDS), and magnetic field dependent magnetization curves of GdON3, GdON5, respectively, for sample GdON5, where fig. 5 represents the particle size distribution of GdON5 as measured from the HR-TEM photograph of fig. 4 (f). The result shows that the sample GdON1-5 of the embodiment has good aqueous phase dispersibility and uniform particle size; the average grain diameter of GdON5 is 1.9 nm; GdON5 is composed mainly of Gd and O, so the component should be Gd₂O₃(ii) a The saturation magnetization of GdON5 was 0.09 emu/g.

Example 2

Preparation of gadolinium oxide-iron oxide composite nanoparticles (FeGd-HN)

40mL of a polyacrylic acid solution (molecular weight: 1800) was prepared at a concentration of 4.0 mg/mL. Nitrogen was bubbled for 50 minutes (deoxygenated) and the solution was heated to 100 ℃. 0.8mL of ferric ion solution (500mM ferric chloride, 250mM ferrous sulfate) was added via syringe, followed immediately by 12mL of aqueous ammonia (28%), and the reaction was carried out for 30 minutes with magnetic stirring. Then, 0.8mL of gadolinium nitrate solution (62.5 to 1000mM) was added via a syringe, followed immediately by 6.0mL of aqueous ammonia solution (28%), and the reaction was carried out for 90 minutes with magnetic stirring. Cooling to room temperature, purifying by dialysis (molecular weight cut-off of 6-8kDa), and concentrating by ultrafiltration (molecular weight cut-off of 3kDa) to obtain FeGd-HN. 1000,750,500,250,125, and the nano particles prepared from 62.5mM gadolinium nitrate solution are FeGd-HN1-6 respectively, and the relevant synthesis conditions and the characterization results are shown in Table 2.

In order to improve the active targeting effect of the FeGd-HN3 nanoparticles on tumors, the surface carboxyl of the nanoparticles can be activated by EDC/NHS to be mixed with a target molecule RGD dimer (RGD2, Glu- { Cyclo [ Arg-Gly-Asp- (D-Phe) -Lys)]}₂) And reacting to obtain FeGd-HN3 (namely FeGd-HN3-RGD2) coupled with RGD 2.

TABLE 2 FeGd-HN nanoparticles Synthesis conditions and characterization results

^aThe concentrations of reactants gadolinium nitrate, ferric chloride and ferrous sulfate;

^bhydrodynamic diameter (d) measured by Dynamic Light Scattering (DLS)_h)；

^cThe iron or gadolinium content in the nano particles accounts for the mole percentage of the iron or gadolinium added in the raw materials;

^dthe molar ratio of iron to gadolinium in the obtained nanoparticles.

FIG. 8 is a Scanning Transmission Electron Microscope (STEM) image of samples FeGd-HN1, FeGd-HN3 and FeGd-HN 6; FIG. 9 shows the characterization results of Electron Energy Loss Spectroscopy (EELS) corresponding to FeGd-HN1, FeGd-HN3 and FeGd-HN6 in FIG. 8. EELS data is obtained from white boxed areas in STEM pictures. The results show that the samples FeGd-HN1, FeGd-HN3 and FeGd-HN6 have different Gd contents, the structure is a core-shell structure, and the core is Fe₃O₄The shell is Gd₂O₃。

FIGS. 10 to 13 are HR-TEM photographs of FeGd-HN3 and FeGd-HN3-RGD2, particle size distributions measured by DLS, energy dispersive X-ray spectroscopy (EDS) of FeGd-HN3, and magnetic field-dependent magnetization curves of FeGd-HN3 and FeGd-HN3-RGD 2. The results show that FeGd-HN3 and FeGd-HN3-RGD2 both have good aqueous phase dispersibility, and the hydraulic particle sizes are respectively 6.5nm and 8.5 nm. FeGd-HN3 mainly comprises Fe, Gd and O,therefore, the component should be Fe₃O₄And Gd₂O₃. The saturation magnetization of FeGd-HN3 and FeGd-HN3-RGD2 is 11.5 and 12.4emu/g respectively.

Samples FeGd-HN3, FeGd-HN3-RGD2 and a commercially available MRI contrast agent Magnevist (i.e., Magnevist) prepared in the example were taken as MRI contrast agents to measure T₁Relaxation Rate (1/T)₁) And T₂Relaxation Rate (1/T)₂) Wherein, FeGd-HN3 and FeGd-HN3-RGD2 of the embodiment are respectively measured from three batches of synthesized products under the same conditions; magnevist takes three different bottled products for measurement; the magnetic field used for the measurement was 1.5T. According to T₁Relaxation Rate and T₂Relaxation Rate with gadolinium concentration (C)_Gd) Or iron concentration (C)_Fe) The change of (a) is used for calculating the slope of the change of (b), namely r₁And r₂The value is obtained. The results show that r of FeGd-HN3 and FeGd-HN3-RGD2 prepared in this example₁Values 73.5. + -. 2.6 and 70.0mM, respectively^-1s^-1All are far higher than r of Magen Wei display₁Values (4.25. + -. 0.07 mM)^- ¹s^-1). R of FeGd-HN3 and FeGd-HN3-RGD2 prepared in this example₂/r₁The ratio is 1.01 plus or minus 0.04 and 1.03 respectively, and is lower than r of the horse root₂/r₁Ratio (1.06. + -. 0.02).

The tail vein of the U-87MG tumor-bearing mice is injected with Magnevist (Magnevist), FeGd-HN3 or FeGd-HN3-RGD2, and the gadolinium injection dose is 5.0 MG/kg. In vivo T-treatment of U-87MG tumor-bearing mice after injection₁Weighted magnetic resonance imaging and its tumor signal enhancement quantitative analysis. The results showed (as shown in fig. 14, 15) that the maximum signal enhancement (Δ SNR) of the tumor after tail vein injection of Magnevist (Magnevist), FeGd-HN3 or FeGd-HN3-RGD2 was 75 ± 11%, 342 ± 47% and 477 ± 44%, respectively. These experimental results indicate that FeGd-HN3 or FeGd-HN3-RGD2 prepared in this example is more excellent T than Magen vitamin₁A contrast agent.

Example 3

Preparation of gadolinium oxide-manganese oxide composite nanoparticles (GdMn-HN)

40mL of a polyacrylic acid solution (molecular weight: 1800) was prepared at a concentration of 4.0 mg/mL. Bubbling with nitrogen for 50 min (deoxygenating) and thenThe solution was heated to 100 ℃. 0.8mL of manganese oxide nanoparticle solution (MnO ) was added through a syringe₂Or Mn₃O₄，C_Mn500mM), after magnetically stirring for 30 minutes, 0.8mL of gadolinium nitrate solution (400mM) was further added, followed immediately by 6.0mL of aqueous ammonia solution (28%), and the reaction was carried out for 90 minutes with magnetic stirring. Cooling to room temperature, purifying by dialysis (molecular weight cut-off of 6-8kDa), and concentrating by ultrafiltration (molecular weight cut-off of 3kDa) to obtain GdMn-HN.

Example 4

Preparation of gadolinium oxide-gold composite nanoparticle (GdAu-HN)

40mL of a polyacrylic acid solution (molecular weight: 1800) was prepared at a concentration of 4.0 mg/mL. Nitrogen was bubbled for 50 minutes (deoxygenated) and the solution was heated to 100 ℃. 0.8mL of gold nanoparticle solution (C) was added first via syringe_Au50mM), after magnetically stirring for 30 minutes, 0.8mL of gadolinium nitrate solution (100mM) was further added, followed immediately by 6.0mL of aqueous ammonia solution (28%), and the reaction was carried out for 90 minutes with magnetic stirring. Cooling to room temperature, purifying by dialysis (molecular weight cut-off of 6-8kDa), and concentrating by ultrafiltration (molecular weight cut-off of 3kDa) to obtain FeMn-HN.

Example 5

Preparation of gadolinium oxide-mesoporous silicon composite nanoparticles (GdSi-HN)

40mL of a polyacrylic acid solution (molecular weight: 1800) was prepared at a concentration of 4.0 mg/mL. Nitrogen was bubbled for 50 minutes (deoxygenated) and the solution was heated to 100 ℃. 0.8mL of mesoporous silicon nanoparticle solution (10mg/mL) was added via a syringe, and after magnetically stirring for 30 minutes, 0.8mL of gadolinium nitrate solution (400mM) was added, followed immediately by 6.0mL of aqueous ammonia solution (28%), and the reaction was carried out for 90 minutes under magnetic stirring. Cooling to room temperature, purifying by dialysis (molecular weight cut-off of 6-8kDa), and concentrating by ultrafiltration (molecular weight cut-off of 3kDa) to obtain GdSi-HN.

Example 6

Preparation of gadolinium oxide-albumin composite nanoparticle (GdAN-HN)

40mL of a polyacrylic acid solution (molecular weight: 1800) was prepared at a concentration of 4.0 mg/mL. Nitrogen was bubbled for 50 minutes (deoxygenated) and the solution was heated to 100 ℃. 0.8mL of albumin nanoparticle solution (AN,10mg/mL) was added via syringe, and after 30 minutes of magnetic stirring, 0.8mL of gadolinium nitrate solution (400mM) was added, followed immediately by 6.0mL of aqueous ammonia (28%), and the reaction was carried out for 90 minutes with magnetic stirring. Cooling to room temperature, purifying by dialysis (molecular weight cut-off of 6-8kDa), and concentrating by ultrafiltration (molecular weight cut-off of 3kDa) to obtain GdAN-HN.

Claims

1. The nano-particle containing gadolinium oxide has a nano-gadolinium oxide core, and a hydrophilic high molecular compound is coated on the surface of the nano-gadolinium oxide core; the gadolinium oxide-containing nanoparticles are obtained by adding a gadolinium ion solution into a hydrophilic polymer solution, and stirring and reacting for more than 10 minutes at 60-100 ℃ in the presence of alkali liquor; the hydrophilic polymer compound is polyacrylic acid.

2. A method for preparing gadolinium oxide-containing nanoparticles of claim 1, consisting essentially of the steps of:

(1) preparing a hydrophilic high molecular compound solution with the concentration of 0.5-50 mg/mL, and deoxidizing for later use; the hydrophilic high molecular compound is polyacrylic acid;

(2) heating the solution prepared in the step (1) to 60-100 ℃, and adding a gadolinium ion solution with the concentration of 30-1000 mM and an alkali solution; the volume ratio of the polymer solution to the gadolinium ion solution is 500-5.0; the volume ratio of the alkali solution to the gadolinium ion solution is 0.1-100; stirring and reacting for more than 10 minutes; thus obtaining the gadolinium oxide-containing nano particles.

3. The method of claim 2, wherein: the concentration of the aqueous polymer compound solution in the step (1) is 2.0-10 mg/mL.

4. The method of claim 2, wherein: the concentration of the aqueous polymer compound solution in the step (1) is 4.0 mg/mL.

5. The method of claim 2, wherein: the concentration of the gadolinium ion solution in the step (2) is 100-300 mM.

6. The method of claim 2, wherein: the concentration of the gadolinium ion solution in the step (2) is 125 mM.

7. The method of claim 2, wherein: the volume ratio of the polymer solution to the gadolinium ion solution in the step (2) is 100-25.

8. The method of claim 2, wherein: the volume ratio of the polymer solution to the gadolinium ion solution in the step (2) is 50.

9. The method of claim 2, wherein: the volume ratio of the alkali solution to the gadolinium ion solution in the step (2) is 2-15.

10. The method of claim 2, wherein: the volume ratio of the alkali solution to the gadolinium ion solution in the step (2) is 7.5.

11. The method of claim 2, wherein: and (3) stirring and reacting for 30-120 minutes in the step (2).

12. The method of claim 2, wherein: the stirring reaction time in the step (2) is 60 minutes.

13. The method of any one of claims 2-12, wherein: in the step (2), the gadolinium ion solution is selected from any one solution or a mixed solution of more than two solutions of gadolinium chloride, gadolinium nitrate, gadolinium fluoride or gadolinium bromide.

14. The method of any one of claims 2-12, wherein: the gadolinium ion solution in the step (2) is selected from gadolinium chloride or gadolinium nitrate solution.

15. The method of any one of claims 2-12, wherein: the alkali solution in the step (2) is selected from one or more than two mixed solutions of ammonia water, sodium hydroxide or potassium hydroxide solution.

16. The method of claim 2, comprising the steps of:

(1) preparing a polyacrylic acid solution with the concentration of 4.0mg/mL, and deoxidizing for later use;

(2) heating the solution prepared in the step (1) to 100 ℃, and adding a 125mM gadolinium nitrate solution and a 20-28% ammonia water solution; the volume ratio of the polyacrylic acid solution to the gadolinium nitrate solution is 50; the volume ratio of the ammonia water solution to the gadolinium nitrate solution is 7.5; stirring and reacting for 60 minutes; thus obtaining the gadolinium oxide-containing nano particles.

17. A gadolinium oxide-containing composite nanoparticle, which is formed by compounding the gadolinium oxide-containing nanoparticle of claim 1 with other nanoparticles, wherein the outer layer of the other nanoparticles is coated with a hydrophilic polymer compound, and the inner core is any one of iron oxide nanoparticles, manganese oxide nanoparticles, gold nanoparticles, mesoporous silicon nanoparticles or albumin nanoparticles; the hydrophilic polymer compound is polyacrylic acid.

18. Use of a gadolinium oxide containing nanoparticle according to claim 1 or a gadolinium oxide containing composite nanoparticle according to claim 17 in the preparation of a contrast agent for magnetic resonance imaging.