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1.
The optimization of the radiolabeling yield of cefazolin with 99mTc was described. Dependence of the labeling yield of 99mTc-cefazolin complex on the amounts of cefazolin and SnCl2·2H2O, pH and reaction time was studied. Cefazolin was labeled with 99mTc with a labeling yield of 89.5 % by using 1 mg cefazolin, 5 μg SnCl2·2H2O at pH 4 and 30 min reaction time. The radiochemical purity of 99mTc-cefazolin was evaluated with ITLC. The formed 99mTc-cefazolin complex was stable for a time up to 3 h, after that the labeling yield decreased 64.0 % at 8 h. Biological distribution of 99mTc-cefazolin complex was investigated in experimentally induced inflammation mice, in the left thigh, using Staphylococcus aureus (bacterial infection model) and turpentine oil (sterile inflammation model). Both thighs of the mice were dissected and counted and the ratio of bacterial infected thigh/contralateral thigh was then evaluated. In case of bacterial infection, T/NT for 99mTc-cefazolin complex was 8.57 ± 0.4 after 0.5 h, which was higher than that of the commercially available 99mTc-ciprofloxacin under the same experimental conditions. The ability of 99mTc-cefazolin to differentiate between septic and aseptic inflammation indicates that 99mTc-cefazolin could undergo further clinical trials to be used for imaging sites of infection.  相似文献   

2.
Phytochlorin [21H, 23H-Porphine-7-propanoicacid, 3-carboxy-5-(carboxymethyl)13-ethenyl-18-ethyl-7,8-dihydro-2,8,12,17-tetramethyl-,(7S,8S)] was labeled with 99mTc and the factors affecting the labeling yield of 99mTc-phytochlorin complex were studied in details. At pH 10, 99mTc-phytochlorin complex was obtained with a high radiochemical yield of 98.4 ± 0.6 % by adding 99mTc to 100 mg phytochlorin in the presence of 75 μg SnCl2·2H2O after 30 min reaction time. The molecular modeling study showed that the structure of 99mTc-phytochlorin complex presents nearly linear HO–Tc–OH unit with an angle of 179.27° and a coplanar Tc(N1N2N3N4) unit. Biodistribution of 99mTc-phytochlorin complex in tumor bearing mice showed high T/NT ratio (T/NT = 3.65 at 90 min post injection). This preclinical study showed that 99mTc-phytochlorin complex is a potential selective radiotracer for solid tumor imaging and afford it as a new radiopharmaceutical suitable to proceed through the clinical trials for tumor imaging.  相似文献   

3.
1-(2-methoxy phenyl) piperazine fragment of WAY100635 or its phenolic analogue, derived from DWAY is used to design the desired structure of 5HT1A receptor imaging agents. In this study a DWAY analogue was labeled with 99mTc-nitrido ([99mTcN]2+) core via dithiocarbamate. 2-(piperazin-1-yl) phenol dithiocarbamate was synthesized by the reaction of 2-(piperazin-1-yl) phenol with an equivalent amount of carbon disulfide in KOH solution then radiolabeled with 99mTc-nitrido core. The final complex was characterized by HPLC and its radiochemical purity was more than 90 %. In vitro stability studies have shown the complex was stable at least 4 h after labeling at room temperature. The n-octanol/water partition coefficient experiment demonstrated log p = 1.34 for 99mTcN–OHPP–DTC. Biodistribution results showed that radio tracer had moderate brain uptake (0.39 ± 0.03 %ID/g at 15 min and 0.29 ± 0.02 %ID/g at 120 min) and good retention, suggesting that this complex may lead to a further development of a radiotracer with specific binding to 5-HT1A receptor.  相似文献   

4.
Gemifloxacin, a novel, 4th generation fluoroquinolone derivative, was labeled with99mTc; its freeze dried kits were prepared and used for infection imaging. Kits showed great stability with higher labeling efficiency. Kits were synthesized through a simple method; developed at room temperature without HCl and heating with low colloidal content. Reaction conditions were optimized in order to get maximum radiochemical purity. Highest labeling efficiency (99 ± 0.05)% was achieved when 1.0 mg gemifloxacin was labeled with 10 mCi sodium pertechnetate in the presence of 50 μg SnCl2 and 300 μg D-penicillamine at room temperature. Radiolabeled antibiotic kits were preclinically assessed such as in-vitro stability, lipophilicity, protein binding, in-vitro binding with bacterial strains and pharmacokinetic investigations in animals. Kits were found highly stable for 6 h both at room temperature and at 37 °C in serum. Biodistribution showed excellent uptake of activity at infection site (in Pseudomonas aeruginosa, Salmonella typhi and Klebsiella pneumoniae). Biodistribution data showed that 99mTc-gemifloxacin has the potential and may be used for infection imaging.  相似文献   

5.
The radiolabeling of trovafloxacin dithiocarbamate (TVND) with technetium-99m using [99mTc-N]2+ core was investigated and biologically assessed as prospective infection imaging agent. The achievability of the 99mTcN-TVND complex as a future MRSA infection radiotracer was investigated in artificially methicillin-resistant Staphylococcus aureus (MRSA) infected male Sprague–Dawley rats (MSDR). Radiochemically the 99mTcN-TVND complex was characterized in terms of radiochemical purity (RCP) in saline, in vitro permanence in serum, in vitro binding with MRSA and biodistribution in living and heat killed MRSA infected MSDR. Radiochemically the complex showed stability in saline with a 97.90 ± 0.22% yield and serum at 37 °C up to 4 h. The 99mTcN-TVND complex showed saturated in vitro binding with MRSA. Normal in vivo uptake in the MRSA infected MDRS was observed with a five fold uptake in the infected muscle as compared to inflamed and normal muscles. The high RCP values, in vitro permanence in serum, better in vitro binding with MRSA, biodistribution behavior and the target to non-target (infected to inflamed muscle) ratios posed the 99mTcN-TVND complex as a promising MRSA infection radiotracer.  相似文献   

6.
The optimization of the radiolabeling yield of ciprofloxacin analogous, norfloxacin, with technetium-99m (99mTc) was described. Dependence of the labeling yield of 99mTc–norfloxacin complex on the concentration of norfloxacin, SnCl2·2H2O content, pH of the reaction mixture and reaction time was studied. Norfloxacin was labeled with 99mTc at pH 3 with a labeling yield of 95.4% by using 5 mg norfloxacin, 50 μg SnCl2·2H2O and 30 min reaction time. The formed 99mTc–norfloxacin complex was stable for a time up to 3 h. Biological distribution of 99mTc–norfloxacin complex was investigated in experimentally induced inflammation rats using Staphylococcus aureus (bacterial infection model) and heat killed Staphylococcus aureus and turpentine oil (sterile inflammation model). In case of bacterial infection, the T/NT value for 99mTc–norfloxacin complex was found to be 6.9 ± 0.4 which was higher than that of the commercially available 99mTc–ciprofloxacin under the same experimental condition.  相似文献   

7.
This paper addresses the development of two new radiopharmaceuticals for infection imaging. The optimization of the labeling yield of ciprofloxacin analogous, lomefloxacin and ofloxacin, with 99mTc is described. 99mTc-lomefloxacin was obtained with a radiochemical yield of 93.6% by adding 99mTc to 2.5 mg lomefloxacin in the presence of 50 μg SnCl2 while 99mTc-ofloxacin was obtained (96.6%) by adding 99mTc to 2 mg ofloxacin in the presence of 50 μg SnCl2. Biodistribution studies in rats were carried out in experimentally induced infection in the left thigh using Staphylococcus aureus. Both thighs of the rats were dissected and counted and the ratio of bacterial infected thigh/contralateral thigh was then evaluated. 99mTc-lomefloxacin showed higher uptake (T/NT = 6.5±0.5) in the infectious lesion than 99mTc-ofloxacin (T/NT = 4.3±0.6) and abscess-to-muscle ratios for both preparations were higher than that of 99mTc-ciprofloxacin (T/NT = 3.8±0.8), indicating that 99mTc-lomefloxacin could be used for infection imaging.  相似文献   

8.
In order to seek novel technetium-99m bacterial infection imaging agents, a ciprofloxacin xanthate (CPF2XT) was synthesized and radiolabeled with [99mTcN]2+ core to obtain the 99mTcN-CPF2XT complex, which exhibited high radiochemical purity, hydrophilicity, and good stability in vitro. The bacteria binding assay indicated that 99mTcN-CPF2XT had specificity to bacteria. A study of biodistribution in mice showed that 99mTcN-CPF2XT had a higher uptake in bacterial infection tissues than in turpentine-induced abscesses, indicating that it could distinguish bacterial infection from sterile inflammation. Compared to 99mTcN-CPFXDTC, the abscess/blood and abscess/muscle ratios of 99mTcN-CPF2XT were higher and the uptakes of 99mTcN-CPF2XT in the liver and lung were obviously decreased. The results suggested that 99mTcN-CPF2XT would be a potential bacterial infection imaging agent.  相似文献   

9.
In the present study synthesis of the 99mTc?CCNN complex and its efficacy as a prospective Staphylococcus aureus (S. aureus) infection imaging agent was assessed. The 99mTc?CCNN complex was characterized in terms of stability in saline, serum, in vitro binding with S. aureus and in vivo percent absorption in male Wister rats (MWR) infected with live and heat killed S. aureus. Radiochemically the 99mTc?CCNN complex showed stable behavior in saline and serum at different intervals. At 30 min after reconstitution the complex showed maximum radiochemical purity (RCP) yield of 97.55 ± 0.22%. The RCP yield decreased to 90.50 ± 0.18% within 240 min. In serum, 18.15% unwanted side product was appeared within 16 h of the incubation. In vitro saturated binding with S. aureus was observed at different intervals with a 62.00% maximum at 90 min. Normal percent in vivo uptake was observed in MWR artificially infected with live S. aureus with a five times higher in the infected muscle as compared to the inflamed and normal muscles. No difference in the percent uptake of the complex in MWR infected with heat killed S. aureus in the infected, inflamed and normal muscles were observed. Based on the promising in vitro and in vivo radiochemical and biological characteristics, we recommend the 99mTc?CCNN complex for in vivo localization of the S. aureus infectious foci.  相似文献   

10.
《中国化学快报》2022,33(7):3497-3501
Tumor-related PD-L2 expression is associated with the clinical efficacy of PD-1/PD-L1 blockade therapy. PD-L2-specific imaging can help selecting patients for appropriate immunotherapy. In this study, a PD-L2-targeting peptide (PDP2) was screened by the one-bead one-compound combinatorial library approach. Using the retro-inverso d-peptide of PDP2 (RD-PDP2) and PEGylation strategies, we developed a novel Tc-99m-labeled PD-L2-targeting peptide as a SPECT tracer (99mTc-PEG6-RD-PDP2) for imaging of tumor PD-L2 expression. The radiolabeling yield of 99mTc-PEG6-RD-PDP2 was greater than 95% by the standard HYNIC/tricine/TPPTS labeling procedure. 99mTc-PEG6-RD-PDP2 displayed high PD-L2-binding specificity both in vitro and in vivo. SPECT/CT imaging with 99mTc-PEG6-RD-PDP2 showed that the A549-PD-L2 tumors were clearly visualized, whereas the signals in PD-L2-negative A549 tumors were much lower. In vivo blocking study suggested that the tumor uptake of 99mTc-PEG6-RD-PDP2 was PD-L2 specifically mediated. 99mTc-PEG6-RD-PDP2 is a promising SPECT probe for the non-invasive imaging of tumor PD-L2 expression and has a great potential in guiding the anti-PD-1 or anti-PD-L1 immunotherapy of cancer.  相似文献   

11.
In the current investigation complexation of the gemifloxacin (GIN) with technetium-99 m (99mTc) and its biological evaluation in artificially Streptococcus pneumoniae (S. pneumoniae) infected rats was assessed as potential S. pneumoniae infection radiotracer. Radiochemically the 99mTc-GIN complex was further analyzed in terms of stability in saline, in vitro stability in serum at 37 °C, in vitro binding with S. pneumoniae and biodistribution in artificially S. pneumoniae (living and heat killed) infected rats. The complex was found 97.25 ± 0.25% radiochemically stable in saline at 30 min after reconstitution. The stability of the 99mTc-GIN complex was decreased to 90.50 ± 0.20% within 240 min after reconstitution. In serum the 99mTc-GIN complex showed stable profile with the appearance of 18.85% free tracer within 16 h of incubation. The 99mTc-GIN complex showed saturated in vitro binding with S. pneumoniae after different intervals. Almost five fold uptake was observed in living S. pneumoniae infected muscle of the rats as compared to the inflamed and normal muscle. No significant difference in the uptake of heat killed S. pneumoniae infected, inflamed and normal muscles of the rats. The high RCP yield in saline, in vitro permanence in serum, in vitro binding with living S. pneumoniae and biodistribution in artificially S. pneumoniae infected rats we recommend the 99mTc-GIN as potential S. pneumoniae infection radiotracer.  相似文献   

12.
The aim of this work is the development of new radiopharmaceuticals for imaging infection and inflammation in human. Gatifloxacin (fluoroquinolone derivative) and cefepime (cephalosporine derivative) are antibiotics used to treat bacterial infections were investigated to label with one of the most important radioactive isotopes (technetium-99m). The reaction parameters that affect the labeling yield such as substrate concentration, stannous chloride dihydrate concentration, pH of the reaction mixture, and reaction time were studied to optimize the labeling conditions. Maximum radiochemical yield of 99mTc–gatifloxacin (90  ± 1.8%) complex was obtained by using 50 μg SnCl2·2H2O and 2.5 mg gatifloxacin at pH 10 while 99mTc–cefepime was prepared at pH 8 with a maximum radiochemical yield of 98  ± 1.4% by adding 99mTc to 5 mg cefepime in the presence of 50 μg SnCl2·2H2O. Biological distribution of 99mTc–gatifloxacin and 99mTc–cefepime was carried out in experimentally induced infection rats, in the left thigh, using Escherichia coli. Both thighs of the rats were dissected and counted and the ratio of bacterial infected thigh/contralateral thigh was then evaluated. T/NT for both 99mTc–gatifloxacin and 99mTc–cefepime was found to be 4.5  ± 0.3 and 8.4  ± 0.1, respectively, which was higher than that of the commercially available 99mTc–ciprofloxacin. The abscess to normal muscle ratio indicated that 99mTc–cefepime could be used for infection imaging. Besides, in vitro studies showed that 99mTc–cefepime can differentiate between bacterial infection and sterile inflammation.  相似文献   

13.
Shikonin was isolated from Ratanjot pigment then the obtained shikonin was well characterized. This study is aimed to optimize radiolabeling yield of shikonin with 99mTc with respect to factors that affect the reaction conditions such as shikonin amount, SnCl2·2H2O amount, reaction time and pH of the reaction mixture. In vitro stability of the radiolabeled complex was checked and it was found to be stable for up to 6?h. Biodistribution studies showed that, 99mTc?Cshikonin accumulate in tumor sites with higher T/NT than other currently available 99mTc(CO)3-VIP, 99mTc?Cnitroimidazole analogues and 99mTc?Cpolyamine analogues indicating that shikonin deliver 99mTc to the tumor sites with a percentage sufficient for imaging and can overcome many drawbacks of other radiopharmaceuticals used for tumor imaging.  相似文献   

14.
The 2-phenyl benzothiazole pharmacophore is known to have high affinity for amyloid beta (Aβ) and is therefore derivatized, to [N-(4′-benzothiazol-pyridin-2-yl-methyl-amino)-acetic acid (BTPAA)] for radiolabeling with [99mTc(CO)3(H2O)3]+ precursor. The radiotracer, 99mTc(CO)3–BTPAA is evaluated in vitro and in vivo to determine its binding with the Aβ and ability to cross the blood brain barrier. The radiotracer prepared in >95 % radiochemical yield, showed ~25 % inhibition in presence of thioflavin-T, indicating its specificity towards aggregated Aβ protein. The radiotracer also showed brain uptake of 0.25 ± 0.04 % injected dose/g at 2 min post injection, indicating its ability to cross the blood brain barrier.  相似文献   

15.
The aim of this study was to synthesis, a radiolabeled (99mTc) new somatostatin-analogue 6-hydrazinopyridine-3-carboxylic-acid (HYNIC)-Asn3-octreotate (99mTc-HYNIC-AATE), and to evaluate as a candidate for imaging somatostatin-receptor (SSTR)-positive tumors and also compare it with 99mTc-HYNIC-Tyr3-octreotide (99mTc-HYNIC-TOC). Synthesis was performed by Fmoc-solid-phase strategy and 99mTc labeled by SnCl2. Biodistribution and imaging properties of new radiopeptide were also studied in C6 tumor bearing rat. Radiolabeling was performed at high specific activities and it showed high binding-affinity for SSTR2. In biodistribution, radiopeptides have showed high and receptor-specific uptake in the SSTR2 positive organs, tumor with rapid renal excretion from non-target tissues. These results demonstrated that 99mTc-HYNIC-AATE is a new specific radioligand for scintigraphy of somatostatin-receptor-positive tumors.  相似文献   

16.
7-Bromo-1,4-dihydro-4-oxo-quinolin-3-carboxylic acid (BDOQCA), was synthesized with a yield of 93% and well characterized. The obtained compound was investigated to label with one of the most important radioactive isotopes (technetium-99m). Effect of BDOQCA concentration, stannous chloride dihydrates (SnCl2.2H2O) concentration, pH and reaction time on the percent labeling yield of 99mTc-BDOQCA complex was studied in details. 99mTc-BDOQCA complex was obtained at a maximum yield of 97.3% by mixing 2.5 mg of BDOQCA with 25 μg SnCl2.2H2O at pH 6 and 30 min reaction time and the formed complex was stable for a time up to 8 h with a maximum yield of 97.3%. Biodistribution studies in mice were carried out using experimentally induced infection in the left thigh using E. coli. Both thighs of the mice were dissected and counted to evaluate the ratio of bacterial infected thigh/contralateral thigh. Higher uptake in the infected thigh was observed after 2 h of IV administration of 99mTc-BDOQCA complex (T/NT = 7.6 ± 0.6%) than that of the commercially available 99mTc-ciprofloxacin complex (T/NT = 3.8 ± 1%). The in vitro binding and biodistribution of 99mTc-BDOQCA complex in the septic and aseptic inflammation bearing mice showed that, 99mTc-BDOQCA complex is a promising agent for infection imaging and can differentiate between infected and inflamed muscle.  相似文献   

17.
Summary The ubiquicidin 29-41 fragment (UBI) is a cationic antimicrobial peptide. The aim of this study was to develop an instant kit formulation for the preparation of 99mTc-UBI 29-41 in high radiochemical yield and to evaluate its use as an infection imaging agent in humans. The components were selected to produce a direct 99mTc labeling, presumably to the amine groups of Lys and Arg7. 99mTc-UBI 29-41 obtained from the lyophilized kit showed radiochemical purity of >97% with an average target/non-target ratio of 2.3±0.6 in positive infection sites at 2 hours. Kits were stable at 4 °C for over 6 months.  相似文献   

18.
The development of technetium-99m-labelled dihydrotetrabenazine (DTBZ) derivative for vesicular monoamine transporter 2 (VMAT2) tracing could be a benefit for single photon emission computed tomography (SPECT) imaging due to easy labelling chemistry and great availability through nuclide generator system. Here, we successfully prepared a technetium-99m-labelled DTBZ derivative and subsequently evaluated its biological activity targeting VMAT2. A novel combination of the bisaminoethanethiol (BAT) chelator scaffold with the biologically active DTBZ vector was performed to synthesize the labelling precursor BAT-P-DTBZ, and it was accomplished in six steps. The technetium-99m labelling was carried out in the radiochemical study of BAT-P-DTBZ conjugate, and the radiolabelling conditions were investigated and optimized. Under the optimized labelling condition, 99mTc-BAT-P-DTBZ was acquired with a good radiochemical purity of above 95 %. The quality control test showed that 99mTc-BAT-P-DTBZ is stable over 6 h and it has a suitable lipophilicity, suggesting successful appositeness for the needs of routine biological evaluation experiments. The in vitro biological evaluation revealed that 99mTc-BAT-P-DTBZ could bind to VMAT2 sites. The in vivo biodistribution study clearly indicated that the pancreas (VMAT2-enriched region) displays relatively high uptake of 99mTc-BAT-P-DTBZ among all organs in mice. The specific VMAT2 binding signal of 99mTc-BAT-P-DTBZ was separately detected in the in vitro and in vivo biological evaluation. Therefore, 99mTc-BAT-P-DTBZ might be a potential imaging agent for monitoring VMAT2 binding sites in the pancreas.  相似文献   

19.
Radiosynthesis of 99mTc-sitafloxacin (99mTc-STF) complex and its efficacy as a potential infection imaging agent was evaluated. Effect of sitafloxacin (STF) concentration, sodium pertechnetate (Na99mTcO4), stannous chloride dihydrate (SnCl2·2H2O), and pH on the % radiochemical purity yield (RCP) of 99mTc-STF complex was studied. A stable 99mTc-STF complex up to 120 min with maximum %RCP yield was observed by mixing 2 mg of STF with 3 mCi of Na99mTcO4 and 150 μL of SnCl2·2H2O (1 μg/μL in 0.01 N HCl) at a pH 5.5. Artificially infected rats with Staphylococcus aureus were used for studying the biodistribution behavior of the 99mTc-STF complex. After 30 min of the intravenous (I.V.) administration of the 99mTc-STF complex, 7.50 ± 0.10% was absorbed in the infected thigh of the rats and the uptake gradually increased to 18.50 ± 0.20% within 90 min. Rabbits with artificially induced infection were used for evaluating the scintigraphic accuracy. Higher uptake in the infected thigh was observed after 2 h of I.V. administration of the 99mTc-STF complex. Target to non-target organ ratio of the % absorbed dose incase of infected/normal muscle was 6.82 ± 0.40, 17.11 ± 0.60, and 23.13 ± 1.00% at 30, 60 and 90 min of administration. Stable and higher %RCP, higher uptake in the infected thigh, and spectral studies, recommend the 99mTc-STF for routine infection imaging.  相似文献   

20.
99mTc-roxifiban was obtained in a high radiochemical yield (98.4%) by complexing ~750 MBq 99mTc with 2.5 mg roxifiban in the presence of 150 µg SnCl2·2H2O. Factors affecting the labelling yield were investigated and optimized. The complex was lipophilic and stable in saline and serum for more than 8 h. The complex structure prediction and molecular docking to its target activated GPIIb/IIIa receptor were performed. The tracer in vitro binding to activated platelets was high (27–32%). In vivo evaluation was performed through clearance, biodistribution and imaging studies in rats. All results supported the usefulness of the tracer as thrombus imaging agent.  相似文献   

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