Composition for diagnosing infectious diseases

Abstract

The present invention relates to a composition for diagnosing infectious diseases and, more particularly, to a composition for diagnosing infectious diseases comprising a radioactive probe capable of specifically detecting inflammation caused by infection.

Description

Composition for diagnosing infectious diseases

[0001] This application claims the benefit of Korean Patent Application No. 10-2024-0062633, filed May 13, 2024, and Korean Patent Application No. 10-2025-0060554, filed May 9, 2025, the entire contents of which are incorporated herein by reference. The present invention relates to a composition for diagnosing infectious diseases, and more particularly, to a composition for diagnosing infectious diseases comprising a radioactive probe capable of specifically detecting inflammation caused by infection.

[0002]

[0003] Infectious diseases are caused by the presence and inhabitation of foreign agents, such as bacteria, fungi, and viruses, in blood, body fluids, and tissues. Without accurate identification and appropriate treatment, these diseases can be life-threatening. While the prevalence of infectious diseases appears to be generally decreasing due to improved hygiene, the threat of infectious diseases with potentially fatal consequences is on the rise due to factors such as the misuse of antibiotics, the increased use of immunosuppressants following transplants, weakened immunity due to cancer treatment, and the growing number of people with underlying conditions like diabetes and hypertension.

[0004]

[0005] In particular, most infectious diseases are accompanied by an inflammatory response at the site of infection, and some of these diseases can trigger a systemic inflammatory response, potentially leading to fatal outcomes. Furthermore, patients with infectious diseases can die, so prompt initiation of appropriate antibiotic treatment is crucial. Therefore, accurate diagnosis and prediction of severity are essential for the survival of patients with infectious diseases.

[0006]

[0007] Because inflammation due to infection and general inflammatory responses can have significant differences in treatment methods, and the treatment choice can have a significant impact on the patient's prognosis, it is very important to accurately diagnose whether the inflammatory response observed in a patient is due to infection.

[0008]

[0009] Accordingly, the inventor of the present invention conducted repeated research to develop a substance that can accurately diagnose and distinguish an inflammatory response due to infection from a general inflammatory response, and as a result, discovered that cyclen, to which a radioactive isotope is coordinated, is specifically absorbed by the site of inflammation due to infection, enabling accurate imaging of the site of infection, thereby completing the present invention.

[0010]

[0011] Accordingly, an object of the present invention is to provide a composition for diagnosing infectious diseases, comprising cyclen coordinated with a radioisotope or a pharmaceutically acceptable salt thereof.

[0012]

[0013] In addition, another object of the present invention is to provide a use of cyclen or a pharmaceutically acceptable salt thereof coordinated with a radioisotope for preparing a composition for diagnosing infectious diseases.

[0014]

[0015] In addition, another object of the present invention is to provide a method for diagnosing an infectious disease comprising the following steps:

[0016] a) Step of extracting a sample;

[0017] b) a step of injecting cyclen coordinated with a radioactive isotope into the sample; and

[0018] c) A step of diagnosing the area with the greatest absorption of the above cyclen as the area where an infectious disease has occurred.

[0019]

[0020] In order to achieve the above-described object of the present invention, the present invention provides a composition for diagnosing an infectious disease, comprising cyclen coordinated with a radioisotope or a pharmaceutically acceptable salt thereof.

[0021]

[0022] In addition, in order to achieve another object of the present invention, the present invention provides the use of cyclen or a pharmaceutically acceptable salt thereof coordinated with a radioisotope for preparing a composition for diagnosing an infectious disease.

[0023]

[0024] In addition, in order to achieve another object of the present invention, the present invention provides a method for diagnosing an infectious disease comprising the following steps:

[0025] a) Step of extracting a sample;

[0026] b) a step of injecting cyclen coordinated with a radioactive isotope into the sample; and

[0027] c) A step of diagnosing the area with the greatest absorption of the above cyclen as the area where an infectious disease has occurred.

[0028]

[0029] Hereinafter, the present invention will be described in detail.

[0030]

[0031] The present invention provides a composition for diagnosing infectious diseases, comprising cyclen coordinated with a radioisotope or a pharmaceutically acceptable salt thereof.

[0032]

[0033] According to one embodiment of the present invention, the cyclen forms a complex through coordination with a radioisotope.

[0034]

[0035] The complex of the present invention refers to a complex in which several other ionic molecules or atomic groups are directionally and three-dimensionally coordinated around one or more atoms or ions to form a single atomic group. Here, the ionic molecules or atomic groups coordinated to the central atom or ion are called ligands. In the composition of the present invention, cyclen is the ligand, and the radioactive isotope that coordinates with it is the central ion.

[0036]

[0037] In the present invention, the cycle is a compound having a structure according to the chemical formula 1 below and is called 1,4,7,10-Tetrazacyclododecane.

[0038]

[0039] [Chemical Formula 1]

[0040]

[0041]

[0042] According to one embodiment of the present invention, a radioactive copper isotope ( 64 Cu) is coordinated 64 It was confirmed that the Cu-cyclen complex was not absorbed in general inflammatory organs or tissues, but was absorbed only in inflammatory areas caused by infection, enabling imaging.

[0043]

[0044] In the present invention, the term "infection" refers to the invasion of one or more types of bacteria, viruses, protozoa, prions, viroids, and fungi into the body, settling, multiplying, and becoming parasitic, and an infectious disease may be any disease that occurs as a result of a reaction in the body as a result of infection by a pathogen. Reactions resulting from an infectious disease may include inflammation, pain, fever, fatigue, edema, and decreased blood pressure.

[0045]

[0046] In the present invention, the infectious disease may preferably be an infectious inflammatory disease, and may be selected from the group consisting of endocarditis, myositis, tuberculosis, pneumonia, urinary tract infection, wound infection, meningitis, osteomyelitis, wound infection, endophthalmitis, endophthalmitis, liver abscess, pharyngitis, diarrhea, sepsis, sinusitis, rhinitis, otitis media, bacteremia, cholecystitis, and parotitis, but is not limited thereto.

[0047]

[0048] In the present invention, the bacteria causing the infection include, for example, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus ferus, Serratia marcescens, Vibrio parahaemolyticus, Streptococcus pneumonia, Staphylococcus saprophyticus, Campylobacter jejuni, Helicobacter pylori, Bacillus cereus, Enterococcus fecalis, Bacillus licheniformis, and Staphylococcus. Staphylococcus epidermidis, Corynebacterium diphtheriae, Klebsiella pneumoniae, Listeria innocua, Burkholderia cepacia, Streptococcus parasanguinis, Salmonella typhimurium, Streptococcus sobrinus, Streptococcus sanguinis, Streptococcus iniae, Streptococcus pyogene, Streptococcus mitis, Listeria Ivanovii subsp ivanovii),Listeria monocytogenes, Streptococcus suis, Clostridium perfringens, Yersinia enterocolitica, Shigella boydii, Shigella flexneri, Shigella sonnei, Salmonella choleraesuis subsp, Salmonella enteritidis, Salmonella bongori, Salmonella enterica, Mycobacterium tuberculosis, Mycobacterium leprae, Clostridium botulinum botulinum), Bacillus anthracis, Yersinia pestis, Chlamydia pneumonia, Borrelia burgdorferi, Coxiella burnetii, Mycobacterium avium, Escherichia coli, Borrelia sp., Bartonella sp., Chlamydia trachomatis, and Mycoplasma pneumonia, but is not limited thereto.

[0049]

[0050] As used herein, the term “pharmaceutically acceptable” means a compound or composition that is suitable for use in contact with the tissues of a subject (e.g., a human) without excessive toxicity, irritation, allergic response, or other problems or complications, and with a reasonable benefit / risk ratio, and is within the scope of sound medical judgment.

[0051]

[0052] In the present invention, the complex of a radioactive isotope and cyclen can be used in the form of a pharmaceutically acceptable salt, and as the salt, an acid addition salt formed by a pharmaceutically acceptable free acid can be useful.

[0053]

[0054] Acid addition salts can be obtained from inorganic acids such as hydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydroiodic, nitrous or phosphorous acids and non-toxic organic acids such as aliphatic mono- and dicarboxylates, phenyl-substituted alkanoates, hydroxyalkanoates and alkanedioates, aromatic acids, aliphatic and aromatic sulfonic acids.

[0055]

[0056] These pharmaceutically non-toxic salts include sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, nitrates, phosphates, monohydrogen phosphates, dihydrogen phosphates, metaphosphates, pyrophosphate chlorides, bromides, iodides, fluorides, acetates, propionates, decanoates, caprylates, acrylates, formates, isobutyrates, caprates, heptanoates, propiolates, oxalates, malonates, succinates, suberates, sebacates, fumarates, maleates, butyn-1,4-dioate, hexane-1,6-dioate, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxybenzoates, phthalates, Contains terephthalate, benzenesulfonate, toluenesulfonate, chlorobenzenesulfonate, xylenesulfonate, phenylacetate, phenylpropionate, phenylbutyrate, citrate, lactate, β-hydroxybutyrate, glycolate, malate, tartrate, methanesulfonate, propanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate or mandelate.

[0057]

[0058] The acid addition salt according to the present invention can be prepared by a conventional method, for example, by dissolving the compound of the above chemical formula 1 in an aqueous acid solution and precipitating the salt using a water-miscible organic solvent such as methanol, ethanol, acetone, or acetonitrile. Alternatively, the acid addition salt can be prepared by evaporating the solvent or excess acid from the mixture and then drying it, or by suction filtration of the precipitated salt.

[0059]

[0060] Additionally, pharmaceutically acceptable metal salts can be prepared using bases. Alkali metal or alkaline earth metal salts are obtained, for example, by dissolving the compound of the above formula 1 in an excess alkali metal hydroxide or alkaline earth metal hydroxide solution, filtering out the undissolved compound salt, and evaporating and drying the filtrate. In this case, sodium, potassium, or calcium salts may be pharmaceutically suitable as metal salts. The corresponding silver salts are obtained by reacting an alkali metal or alkaline earth metal salt with a suitable silver salt (e.g., silver nitrate).

[0061]

[0062] In one aspect of the present invention, the composition may be characterized as a contrast agent composition for positron emission tomography (PET) or PET-CT imaging.

[0063]

[0064] In practical use, the PET contrast agent according to one embodiment of the present invention may be combined with a pharmaceutically acceptable carrier according to conventional pharmaceutical preparation techniques. The carrier may take a wide variety of forms, depending on the desired formulation, for example, for oral or parenteral administration (including intravenous administration).

[0065]

[0066] Additionally, the contrast agent according to one embodiment of the present invention may be administered at a dosage of 0.1 mg / kg to 1 g / kg, more preferably 0.1 mg / kg to 500 mg / kg. Meanwhile, the dosage may be appropriately adjusted according to the patient's age, sex, and condition within the range of daily or annual permissible radiation exposure.

[0067]

[0068] A contrast agent according to one embodiment of the present invention further comprises inert ingredients, including a pharmaceutically acceptable carrier. As used herein, the term "pharmaceutically acceptable carrier" refers to a component of a composition, specifically a pharmaceutical composition, other than the active ingredient. Examples of pharmaceutically acceptable carriers include binders, disintegrants, diluents, fillers, lubricants, solubilizers, emulsifiers, and salts.

[0069]

[0070] In the present invention, the content of the composition is not particularly limited depending on the purpose or aspect of use, and may be, for example, 0.01 to 99 wt%, preferably 0.5 to 50 wt%, and more preferably 1 to 30 wt%, based on the total weight of the composition. In addition, the diagnostic composition according to the present invention may further include additives such as pharmaceutically acceptable carriers, excipients, or diluents in addition to the active ingredient. The diagnostic composition of the present invention may include 0.1 to 99.9 wt% of cyclen or a pharmaceutically acceptable salt thereof coordinated with a radioisotope prepared by the method of the present invention, and may include 99.9% to 0.1 wt% of the carrier.

[0071]

[0072] The above contrast agent can be administered to the subject by parenteral administration, and the parenteral administration can be intravenous injection, intraperitoneal injection, intramuscular injection, or subcutaneous injection, but intravenous administration is most preferred.

[0073]

[0074] The present invention also provides the use of cyclen or a pharmaceutically acceptable salt thereof coordinated with a radioisotope for preparing a composition for diagnosing an infectious disease.

[0075]

[0076] In addition, the present invention provides a method for diagnosing an infectious disease comprising the following steps:

[0077] a) Step of extracting a sample;

[0078] b) a step of injecting cyclen coordinated with a radioactive isotope into the sample; and

[0079] c) A step of diagnosing the area with the greatest absorption of the above cyclen as the area where an infectious disease has occurred.

[0080]

[0081] The composition of the present invention, which includes a complex of a radioactive isotope and cyclen, is not absorbed in general inflammation sites but is absorbed only in inflammation sites caused by infection, enabling imaging, so that it may be possible to diagnose diseases caused by infection with high accuracy.

[0082]

[0083] Figure 1 shows the growth of live Staphylococcus aureus (S. aureus) and heat-killed Staphylococcus aureus. 64 This is the result of comparing the time-dependent absorption of Cu-cyclen.

[0084]

[0085] Figure 2 shows the growth of E. coli over time through a bacterial uptake experiment. 64 This is the result of checking the Cu-cyclen intake rate.

[0086]

[0087] Figure 3 shows the results of observing an animal using a luminescent imaging device after performing one or more methods selected from the group consisting of carotid artery ligation, tubing insertion, and bacterial injection to create an animal model of infective endocarditis.

[0088]

[0089] Figure 4 shows the results of confirming the number of colonies grown after homogenizing and culturing the heart tissue obtained from the Control group, the Sham group that underwent tubing insertion, the Bacteria only group that was injected with bacteria, and the infective endocarditis group (IE model) that was injected with bacteria after tubing insertion, and culturing them on solid culture media.

[0090]

[0091] Figure 5 shows the results of tissue staining to confirm whether the aortic valve was traumatized by tubing insertion and whether bacteria formed colonies.

[0092]

[0093] Figures 6a to 6h are diagrams showing the results of validation and biodistribution analysis of the infective endocarditis (IE) mouse model induced by Staphylococcus aureus ((Figure 6a) Schematic diagram showing the procedure for constructing the sham surgical model and the IE model. (Figure 6b) Photographs of agar plates cultured with serial dilutions of heart homogenates from the sham group and the IE group. (Figure 6c) IVIS bioluminescence images of the IE model. (Figures 6d-f) Control, sham, and IE groups 64 Biodistribution data of Cu-cyclen in the heart (Fig. 6d), blood (Fig. 6e), and kidney (Fig. 6f). (Fig. 6g) Photographs (left) and schematics (right) of excised hearts; the red dotted line indicates the heart section, and the blue dotted line indicates the aortic valve area where bacterial colonies are present (red dots). (Fig. 6h) The heart was divided into three parts, and each part was analyzed. 64 Regional biodistribution of Cu-cyclen. (*p < 0.05, n = 3)).

[0094]

[0095] Figures 7a and 7b 64 This is the result of quantitatively showing the biodistribution of Cu-cyclen by organ.

[0096]

[0097] Figure 8 shows the results for 1 hour in the control, sham and IE models. 64Cu-cyclen dynamic PET / CT images (MIP-PET / CT images acquired at 10, 20, 30, 40, and 60 minutes after injection. White arrows indicate the heart region. The left column shows a schematic diagram of the three experimental groups. The blue line indicates the tube inserted into the aorta, and the red dot indicates bacterial colonies on the aortic valve in the IE model.).

[0098]

[0099] Figures 9a to 9e are at 1 hour after administration. 64 Cu-cyclen and [ 18 F]FDG image analysis results ((Fig. 9a) in the control, sham surgery model, and IE model 64 Static PET / CT image 1 hour after Cu-cyclen injection. White arrow: heart, red triangle: liver, white triangle: kidney, blue triangle: bladder. (Fig. 9b) 64 Cross-sectional and coronal PET / CT images of the heart 1 hour after Cu-cyclen injection. (Fig. 9c) In the PET images 64 Quantification of whole-heart uptake of Cu-cyclen (Fig. 9d) in the MRSA IE model. 64 Static PET / CT image 1 hour after Cu-cyclen injection. (Fig. 9e) In the IE model [ 18 Static PET / CT images 1 hour after F]FDG injection. (*p < 0.05, n=3)).

[0100]

[0101] Figures 10a to 10c are 64 The results of the experiment to identify the uptake target of Cu-cyclen ((Fig. 10a) Autoradiogram of the whole heart section of the IE model. The heart tissue was arranged in a grid pattern from the upper left to the lower right. (Fig. 10b) Autoradiogram of the aortic valve area of ​​the IE model, Gram stain image, and (Fig. 10c) merged image.).

[0102]

[0103] Figures 11a to 11f are for bacterial infection imaging in a Staphylococcus aureus mouse myositis model. 64 Results of the Cu-cyclen pilot study ((Fig. 11a) IVIS bioluminescence image acquired 7 days after injection of S. aureus into the right thigh muscle. (Fig. 11b) 1 hour after injection 64 Biodistribution profiles of Cu-cyclen, showing differences in uptake between the infected and control sites. (Fig. 11c) Maximum intensity projection (MIP) PET image acquired 1 hour after injection. (Fig. 11d) Cross-sectional PET / CT image taken at the level of the bacterial injection site. (Fig. 11e) Photograph of the resected hind limb following PET imaging. (Fig. 11f) Ex vivo PET / CT image of the resected limb, highlighting localized tracer uptake at the infected site (white triangles indicate the S. aureus injection site, p < 0.01, n = 3).)

[0104] Figure 12 shows an animal model of myositis produced using E. coli. 64 This is the result of PET / CT images obtained 1 hour after Cu-cyclen was injected into the tail vein.

[0105]

[0106] Hereinafter, the present invention will be described in detail with reference to the following examples. However, the following examples are intended only to illustrate the present invention and the present invention is not limited thereto.

[0107]

[0108] Example 1: 64 Manufacturing of Cu-cyclen radioactive probe

[0109] Cyclen radiolabeling is 64 The experiment was performed by mixing CuCl₂ with cyclen in ammonium acetate buffer (pH 6.8).

[0110] Afterwards, the reaction was performed at 60℃ and 800 rpm for 30 minutes using a thermomixer.

[0111] The labeling yield and radiochemical purity were confirmed by radio-thin-layer chromatography (Radio-TLC).

[0112]

[0113] Example 2: Bacterial uptake experiment of radioactive probe

[0114] Total 10 8 CFU of S. aureus was inoculated into a test tube containing 5 mL of LB medium.

[0115]

[0116] For comparison, some of the bacterial suspensions were inactivated by heat treatment with a heat block at 100°C for 20 min, and both live and heat-killed bacteria were used in subsequent experiments.

[0117] Each sample contains 0.37 MBq 64 Cu-cyclen was treated and cultured on a digital shaking plate at 37°C. At 10, 20, 30, 60, and 120 minutes, 500 μL aliquots were collected and centrifuged at 2,400 x g for 7 minutes at 4°C to precipitate bacteria. The supernatant was removed, and the precipitate was washed twice with PBS and centrifuged again. Finally, the samples were resuspended in PBS, transferred to new tubes, and radioactivity was measured using a gamma counter.

[0118]

[0119] Heat-killed S. aureus showed almost no absorption over 120 minutes, while live S. aureus showed increased absorption over time (Fig. 1).

[0120]

[0121] Additionally, a bacterial uptake experiment was conducted using Escherichia coli, a Gram-negative bacterium. The bacterial uptake rate increased over time, indicating that even in E. coli, 64It was confirmed that Cu-cyclen was consumed (Fig. 2).

[0122]

[0123] Example 3: Evaluation of diagnostic performance for infective endocarditis (IE)

[0124] 1. Establishment and validation of an animal model of infective endocarditis

[0125] To visually verify the infective endocarditis model, we purchased Staphylococcus aureus Xen36 (Revvity, hereinafter referred to as IVISbrite Staphylococcus aureus) containing the lux operon of the bioluminescent bacterium Photorhabdus luminescens inserted into a plasmid. The bacteria could be observed to emit light without any additional treatment using a luminescent imaging device (IVIS lumina III, Perkin Elmer, USA). Bioluminescence was verified in two cases using IVISbrite Staphylococcus aureus. The bacteria were cultured on agar plates at 37°C for 16 hours. The bacterial liquid culture was injected subcutaneously into mice. Bioluminescence was confirmed whether the bacteria were injected one day before or 30 minutes before imaging, indicating that bioluminescence was maintained even in the subcutaneous tissue of mice.

[0126]

[0127] The infective endocarditis model is induced by bacterial attachment and growth on aortic valve trauma caused by tubing insertion. To confirm that both heart valve trauma and intravenous bacterial injection were required for model creation, various control groups were used. Bioluminescence imaging was obtained by injecting IVISbrite Staphylococcus aureus, verifying the model. No bioluminescence was observed in mice receiving tail vein injections of the bacteria without any additional treatment (Figure 3A).

[0128]

[0129] During tubing insertion, the carotid artery had to be ligated. In mice injected with bacteria after carotid artery ligation but without tubing insertion, no bioluminescence was observed (Fig. 3B). In mice injected without bacteria after tubing insertion, no bioluminescent bacteria were present, so no bioluminescence could be observed (Fig. 3C). In mice injected with IVISbrite Staphylococcus aureus after tubing insertion, a strong bioluminescent signal was observed in the heart (Fig. 3D). These results demonstrated that direct aortic valve trauma by tubing and bacterial injection must be combined to induce infective endocarditis. Furthermore, it was confirmed that the formation of an infective endocarditis model can be easily verified using luminescent imaging equipment when IVISbrite Staphylococcus aureus is used.

[0130]

[0131] The number of bacteria in the heart was quantified in the fabricated model. Hearts were obtained from the following groups: the Control group, which underwent no treatment, the Sham group, which underwent tubing insertion, the Bacteria-only group, which was injected with bacteria only, and the Infective endocarditis group (IE model), which was injected with bacteria after tubing insertion. The hearts were homogenized using liquid nitrogen. The homogenized heart tissue was serially diluted with 1 ml of PBS and cultured on solid culture media. The number of colonies grown on the solid culture media was counted to quantify the number of bacteria in each group. No colonies were observed in the Control or Sham groups. The Bacteria-only group, which was injected with the same number of bacteria as the Infective endocarditis model group, did not exhibit colonies. This suggests that bacteria cannot remain in the heart without valve trauma. A large number of colonies were observed in the Infective endocarditis group, but there were inter-individual differences. A minimum of 1,500 CFU and a maximum of 1,500,000 CFU were observed, which is presumed to be due to differences in the degree of trauma caused by tubing insertion (Fig. 4).

[0132]

[0133] Traumatized aortic valves were induced by tubing insertion, and tissue staining was performed to determine whether fungal colonies had formed. H&E staining images of the control group revealed a typical aortic valve. In contrast, H&E staining images of the infective endocarditis model (IE model) revealed tissue thickened by inflammatory cells. Gram staining images of serial sections revealed black-stained Staphylococcus aureus (white arrows). This confirmed that traumatized aortic valves in the IE model and that fungal colonies were growing (Fig. 5).

[0134]

[0135] 2. Biodistribution and PET / CT imaging in an infective endocarditis model

[0136] This experiment was conducted on the IE model. 64 To confirm the systemic distribution pattern of Cu-cyclen, only animals in which IE was confirmed to be induced by bioluminescence imaging were included in the experiment. Approximately 0.74 MBq was administered through the tail vein to each of the control, sham control, and IE model mice. 64 Cu-cyclen was injected (Fig. 6a). One hour later, the animals were euthanized by cervical dislocation, and major organs, including blood, heart, lungs, muscle, fat, bone, spleen, liver, intestine, and kidney, were harvested. Each tissue was weighed and analyzed for radioactivity using a gamma counter. For cardiac analysis, the heart was cut horizontally into three sections, with the aortic valve (site of bacterial colony) included in the upper section.

[0137] In PET / CT imaging, each group of mice 64 After intravenous injection of Cu-cyclen

[0138] · In dynamic imaging, 37 MBq was injected, and PET scans were performed at 10-minute intervals for 1 hour. CT scans were then performed for 3 minutes.

[0139] · In static imaging, 7.4 MBq was injected and PET (20 minutes) and CT (3 minutes) scans were performed.

[0140]

[0141] When heart homogenates were cultured on agar plates, bacteria were found only in the IE model heart and not in the sham model heart (Fig. 6b).

[0142] Prior to biodistribution studies, the model was validated using IVIS imaging. A strong signal was observed in the aortic valve region where bacterial colonies were formed (Fig. 6c).

[0143] 64 Cu-cyclen biodistribution comparison experiments were conducted on healthy mice, sham models, and IE models (Figs. 6d-f, 7a, and 7b).

[0144] The sham model showed no significant difference in organ uptake compared to the healthy control group, but the IE model showed a significant increase in uptake in the heart, blood, and kidneys. In particular, the uptake in the heart was more than twice as high. 64 Cu-cyclen uptake was observed, which was due to bacterial colonization of the aortic valve (Fig. 6d).

[0145] High radioactivity retention in the blood appears to be due to bacteremia resulting from bacterial injection via the tail vein (Fig. 6e).

[0146] Additionally, acute renal failure, a common complication of IE, occurs. 64 Delayed renal excretion of Cu-cyclen resulted in high accumulation in the kidneys of the IE group (Fig. 6f).

[0147] When the heart was divided into three parts horizontally and analyzed, the uptake was more than 2.5 times higher only in the upper part where the aortic valve is located, and there was no difference between the IE model and the control group in other parts (Figs. 6g, 6h, 7a and 7b).

[0148] All of these data indicate that increased cardiac uptake in the IE model 64 This strongly supports the selective bacterial targeting of Cu-cyclen.

[0149]

[0150] 3. 64 Cu-cyclen and [ 18 PET imaging of an infective endocarditis model using F]FDG

[0151] 64 To evaluate the diagnostic potential of Cu-cyclen, PET / CT scans were performed. Both healthy mice and sham mice were scanned. Dynamic scans were performed at 10-minute intervals for the first hour after tail vein injection (Fig. 8). During the first 20 minutes, there was no significant difference between the IE model and the control group. Although the radioactivity in the blood was rapidly cleared, high blood radioactivity remained, obscuring small bacterial colonies in the aortic valve. However, after 30 minutes, significant blood radioactivity disappeared, and specific uptake in the heart region began to be observed.

[0152] The Sham model showed that the heart was intact despite the presence of aortic valve damage. 64 No Cu-cyclen uptake was observed, and was similar to that of the healthy control group. Up to 60 minutes later, no signal remained in the heart region in the control and sham models, whereas the IE model retained a signal confined to the heart region, allowing high-contrast detection of IE.

[0153]

[0154] Based on the dynamic scan results, a static scan was performed again 1 hour later (Fig. 9a). Strong localized uptake in the heart region was observed only in the IE model, while it was not observed in the control and sham models. In fact, bladder activity was much higher in the control and sham models, whereas bladder uptake was low in the IE model due to slow excretion due to acute renal failure. In the cross-sectional and coronal cross-sectional images, localized uptake (hot spot) was concentrated in the center of the heart (Fig. 9b). Quantitative analysis of PET images showed that the cardiac uptake in the IE model was more than three times higher than that in the control and sham models (Fig. 9c). In the IE model induced by MRSA (Methicillin-resistant Staphylococcus aureus), 64 Cu-cyclen was evaluated, and local uptake was clearly observed in the central region of the heart (Fig. 9d).

[0155] Meanwhile, [ 18 F]FDG-PET images confirmed that strong uptake was observed throughout the heart (Fig. 9e).

[0156]

[0157] 4. Autoradiography and bacterial staining studies

[0158] To precisely identify the focal heart uptake area observed in the PET / CT images of the IE model, the heart was excised and analyzed using autoradiography and Gram stain. The heart tissue was sectioned transversely at 25 μm thickness and autoradiography was performed, and intense focal uptake was observed in the central region (Fig. 10a). This pattern was consistent with that observed in the cross-sectional PET / CT image (Fig. 10b). Gram staining of the same tissue slide revealed a dark purple-stained area in the aortic valve region, indicating Staphylococcus aureus bacterial colonies (Fig. 10b).

[0159] Merging the autoradiography and Gram stain images confirmed that the hotspots precisely matched the bacterial colonies on the aortic valve (Fig. 10c). Enlargement of the aortic valve area in the merged image further confirmed the close correspondence between the autoradiography local uptake sites and the bacterial staining sites (Figs. 10b and 10c).

[0160]

[0161] Example 4: Evaluation of diagnostic performance for infectious myositis

[0162] A Staphylococcus aureus myositis model was created using 6-week-old male BALB / c mice (19-21 g). PBS was injected into the left thigh and 10 8 50 μL of CFU of S. aureus was injected. Induction of myositis was confirmed by bioluminescence imaging.

[0163] In a biodistribution experiment, 0.74 MBq was administered via the tail vein. 64 Tissues were harvested 1 hour after Cu-cyclen injection. Both thigh muscles (PBS injection site and S. aureus infection site) were removed and analyzed for radioactivity using a gamma counter, and the results were expressed as a percentage of the injected radioactivity per gram of tissue (%ID / g). For PET / CT imaging, 7.4-11.1 MBq was injected into the tail vein. 64 Cu-cyclen was injected, and PET (20 minutes) and CT (3 minutes) scans were performed 1 hour after injection. After imaging, the animals were euthanized, and both thighs were collected to determine radiotracer uptake ex vivo. PET / CT data were analyzed by standardized uptake value (SUV) and reviewed using maximum intensity projection (MIP) and cross-sectional images.

[0164]

[0165] First, in the Staphylococcus aureus myositis model, 64We evaluated the ability of Cu-cyclen to target the infection site. Bioluminescent Staphylococcus aureus (Xen36, PerkinElmer) was used to track bacteria using noninvasive optical imaging. IVIS imaging clearly detected bacterial signals in the right thigh muscle (Fig. 11a).

[0166] 64 Biodistribution analysis performed 1 hour after Cu-cyclen injection showed that the left thigh had 0.21 %ID / g and the right thigh had 0.88 %ID / g, indicating that the infected area had 4.2 times higher uptake than the control area (Fig. 11b). PET / CT images also showed no uptake signal in the PBS-injected left thigh, whereas uptake was clearly observed in the Staphylococcus aureus-injected right thigh in both whole-body maximum intensity projection (MIP) and cross-sectional images (Figs. 11c and 11d). To confirm the exact location, both legs of the infection model were removed and ex vivo experiments were performed. 64 Cu-cyclen was accumulated at the site of Staphylococcus aureus infection (Fig. 11e and Fig. 11f).

[0167]

[0168] We created a myositis model using E. coli. 64 Cu-cyclen PET / CT images were obtained. PBS was injected into the left thigh, and E. coli was injected into the right thigh. Four and a half hours after the bacterial injection. 64 PET / CT images were obtained 1 hour after Cu-cyclen was injected into the tail vein. Only in the right thigh. 64 Cu-cyclen intake has been confirmed not only in Staphylococcus aureus but also in Escherichia coli. 64 It was confirmed that detection using Cu-cyclen was possible (Fig. 12).

[0169]

[0170] The composition of the present invention, which includes a complex of a radioactive isotope and cyclen, is not absorbed in general inflamed areas but is absorbed only in inflamed areas caused by infection, enabling imaging. Therefore, it is possible to diagnose diseases caused by infection with great accuracy, and thus has a very high possibility of industrial application.

Claims

1. A composition for diagnosing infectious diseases, comprising cyclen coordinated with a radioactive isotope or a pharmaceutically acceptable salt thereof.

2. In paragraph 1, the radioactive isotope is 11 C, 18 F, 44 Sc, 32 P, 64 Cu, 67 Cu, 68 Ga, 80m Br, 85 Sr, 89 Sr, 86 Y, 90 Y, 99m Tc, 111 In, 114m In, 123 I, 124 I, 125 I, 131 I, 149 Tb, 152 Tb, 153 Sm, 165 Dy, 166 Ho, 169 Er, 177 Lu, 186 Re, 188 Re, 198 Au, 211 At, 212 Pb, 223 Ra, 225 Ac and 255 A composition characterized by being selected from the group consisting of Fm.

3. A composition according to claim 1, characterized in that the infectious disease is selected from the group consisting of endocarditis, myositis, tuberculosis, pneumonia, urinary tract infection, wound infection, meningitis, osteomyelitis, wound infection, endophthalmitis, endophthalmitis, liver abscess, pharyngitis, diarrhea, sepsis, sinusitis, rhinitis, otitis media, bacteremia, cholecystitis, and parotitis.

4. A composition according to claim 1, characterized in that it is for positron emission tomography (PET) or PET-CT imaging.

5. A composition according to claim 1, characterized in that the infection is an infection by at least one of bacteria, viruses, protozoa, prions, viroids, and fungi.

6. In the fifth paragraph, the bacteria are Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus ferus, Serratia marcescens, Vibrio parahaemolyticus, Streptococcus pneumonia, Staphylococcus saprophyticus, Campylobacter jejuni, Helicobacter pylori, Bacillus cereus, Enterococcus fecalis, Bacillus licheniformis, Staphylococcus Staphylococcus epidermidis, Corynebacterium diphtheriae, Klebsiella pneumoniae, Listeria innocua, Burkholderia cepacia, Streptococcus parasanguinis, Salmonella typhimurium, Streptococcus sobrinus, Streptococcus sanguinis, Streptococcus iniae, Streptococcus pyogene, Streptococcus mitis, Listeria Ivanovii subsp ivanovii), Listeria monocytogenes,Streptococcus suis, Clostridium perfringens, Yersinia enterocolitica, Shigella boydii, Shigella flexneri, Shigella sonnei, Salmonella choleraesuis subsp, Salmonella enteritidis, Salmonella bongori, Salmonella enterica, Mycobacterium tuberculosis, Mycobacterium leprae, Clostridium botulinum, Bacillus anthracis A composition characterized in that it is selected from the group consisting of anthracis, Yersinia pestis, Chlamydia pneumonia, Borrelia burgdorferi, Coxiella burnetii, Mycobacterium avium, Escherichia coli, Borrelia sp., Bartonella sp., Chlamydia trachomatis, and Mycoplasma pneumonia.

7. Use of cyclen or a pharmaceutically acceptable salt thereof coordinated with a radioisotope for preparing a composition for diagnosing infectious diseases.

8. In paragraph 7, the radioactive isotope is 11 C, 18 F, 44 Sc, 32 P, 64 Cu, 67 Cu, 68 Ga, 80m Br, 85 Sr, 89 Sr, 86 Y, 90 Y, 99m Tc, 111 In, 114m In, 123 I, 124 I, 125 I, 131 I, 149 Tb, 152 Tb, 153 Sm, 165 Dy, 166 Ho, 169 Er, 177 Lu, 186 Re, 188 Re, 198 Au, 211 At, 212 Pb, 223 Ra, 225 Ac and 255 A use characterized by being selected from the group consisting of Fm.

9. A use according to claim 7, characterized in that the infectious disease is selected from the group consisting of endocarditis, myositis, tuberculosis, pneumonia, urinary tract infection, wound infection, meningitis, osteomyelitis, wound infection, endophthalmitis, endophthalmitis, liver abscess, pharyngitis, diarrhea, sepsis, sinusitis, rhinitis, otitis media, bacteremia, cholecystitis, and parotitis.

10. A use characterized in that it is for positron emission tomography (PET) or PET-CT imaging in accordance with paragraph 7.

11. A use according to claim 7, characterized in that the infection is an infection of at least one of bacteria, viruses, protozoa, prions, viroids, and fungi. 12.a) Step of extracting a sample; b) a step of injecting cyclen coordinated with a radioactive isotope into the sample; and c) A method for diagnosing an infectious disease, comprising a step of diagnosing the area with the greatest absorption of the above-mentioned cyclen as the area where the infectious disease has occurred.

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