Biodistribution and toxicity assessment are critical for safe clinical use of newly developed medicines.Superparamagnetic iron oxide nanoparticles (SPION)are effective carriers for targeted drug delivery.This study ai...Biodistribution and toxicity assessment are critical for safe clinical use of newly developed medicines.Superparamagnetic iron oxide nanoparticles (SPION)are effective carriers for targeted drug delivery.This study aimed to examine the toxicity and biodistribution of SPION coated with polyethylenimine (PEI)(SPION-PEI)designed for small interfering RNA (siRNA) delivery both in vitro and in vivo.SPION-PEI/siRNA complexes were prepared at different weight ratios.Cytotoxic effects of SPION-PEI/siRNA on HSC-T6 cell viability were determined by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT).Rats were divided into three groups:a control group,a normal-saline group and a SPION-PEI/siRNA group.After a single intravenous injection,in vivo nanoparticle biodistribution and accumulation were evaluated by Prussian blue staining in the heart,liver,spleen,lung and kidney 8 h,24 h,and 7 days after the injection.Their distribution was histologically studied at the three time points by measuring ironpositive areas (μm2)in organ sections stained with Prussian blue.The same organs were analyzed by H&E staining for any possible histopathological changes.Furthermore,biochemical indexes such as alanine amino transaminase (ALT),aspartate transaminase (AST),blood urea nitrogen (BUN)and creatinine (CREA)were also assessed at all experimental time points.Electrophoresis exhibited that the SPION-PEI could retard siRNA altogether at weight ratios above 4.MTT assay showed that SPION-PEI loaded with siRNA had low cytotoxicity.In vivo study revealed that the liver and spleen were the major sites of SPION-PEI/siRNA deposition.The iron content was significantly increased in the liver and spleen,peaking 24 h after intravenous injection and then declining gradually.No evidence was found of irreversible histopathological damage to any of the organs tested.These results suggested that most SPION-PEI/siRNA complexes were distributed in the liver and spleen,which might be the target organs of SPION-PEI/siRNA complexes.SPION- PEI/siRNA may serve as in vivo carrier for biomedical medicines.展开更多
A novel zoledronic acid derivative,1-hydroxy-2-(2-propyl-1H-imidazol-1-yl)ethane-1,1-diyldiphosphonic acid (PIDP), was synthesized by three-step reactions from 2-propyl-1H-imidazole. It was labeled with 99Tcm in condi...A novel zoledronic acid derivative,1-hydroxy-2-(2-propyl-1H-imidazol-1-yl)ethane-1,1-diyldiphosphonic acid (PIDP), was synthesized by three-step reactions from 2-propyl-1H-imidazole. It was labeled with 99Tcm in conditions of 0.1 mg SnCl2.2H2O at pH 6.0 and 99TcmO4? in aqueous solution for 20 min at room temperature. The labeling yield and radiochemical purity of 99Tcm-PIDP are both higher than 95%. The biodistribution results show that the bone uptake is up to 8.47% ID/g which is the maximum of bone uptake at 30 min after injection of 99Tcm-PIDP in mice. The pharmacokinetic parameters can be estimated from the exponential equation of C=59.565e-11.307t+2.069e-1.211t. The clear bone image of rabbit was obtained at 120 min after injection of 99Tcm-PIDP. The results indicate that 99Tcm-PIDP has highly selective uptake in the skeletal and low uptake, rapid clearance in soft tissues, so it would be a potential novel bone imaging agent.展开更多
99mTc-HMIBP, a new bone-imaging agent, was prepared by the reduction of 99mTc-pertechnetate in the presence of SnCl2?2H2O. The effects of the amounts of SnCl2?2H2O and HMIBP and the pH value on the labeling yield and ...99mTc-HMIBP, a new bone-imaging agent, was prepared by the reduction of 99mTc-pertechnetate in the presence of SnCl2?2H2O. The effects of the amounts of SnCl2?2H2O and HMIBP and the pH value on the labeling yield and radiochemical purity of 99mTc-HMIBP were investigated. When the amounts of SnCl2?2H2O and HMIBP were more than 10 μg and 2.5 mg, respectively, the pH value was between 2 and 7, and the labeling reaction contin- ued for 10 min, both labeling yield and radiochemical purity of 99mTc-HMIBP were more than 90%. The biodistribu- tion in rats and bone scan in rabbits were also studied. The results showed that the bone uptake is up to 7.94%ID/g at 30 min after injection of 99mTc-HMIBP, bone-to-muscle and bone-to-blood uptake ratios were 20.89 and 16.89, re- spectively. The clear bone image was obtained at 120 min after injection of 99mTc-HMIBP and clearance in soft tissue was visible. All of the above-mentioned results suggested that 99mTc-HMIBP may be a potential bone-imaging agent.展开更多
This work was conducted for radiolabeling of an anticancer antibiotic, i.e. doxorubicin with 61Cu for production of possible tracer used in PET oncology. 61Cu was prepared with natural zinc target and 22 MeV150 μA pr...This work was conducted for radiolabeling of an anticancer antibiotic, i.e. doxorubicin with 61Cu for production of possible tracer used in PET oncology. 61Cu was prepared with natural zinc target and 22 MeV150 μA protons via natZn(p, xn)61Cu reaction with a yield of 123.2 MBq·μA-1·h-1. Optimization reactions were performed for pH, temperature and concentration. Biodistribution of the tracer was studied in normal and fibrosarcoma bearing mice. At the optimized conditions, ITLC showed that radiochemical purity was over 97% with a specific activity of 2.22× 103MBq ·mmol-1·L-1. This was kept unchanged even with presence of human serum as well as room temperature for 5 h. Biodistribution of the tracer in fibrosarcoma bearing mice demonstrated significant tumor uptake after 2 h. This tracer can be used in the detection of various tumors responding to doxorubicin chemotherapy using PET scan and/or determination of tumor therapy response to doxorubicin chemotherapy.展开更多
In this study, a novel technique for the preparation of 125I-5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FIAU) was developed, 125I-FIAU biodistribution profile was detected in Kunming mi...In this study, a novel technique for the preparation of 125I-5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FIAU) was developed, 125I-FIAU biodistribution profile was detected in Kunming mice and the possibility of using FTAU radio-labeling for reporter gene imaging was explored. 5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FTAU) was labeled with radioiodine (125I). A rotary evaporation method was used to remove excess methanol. The reactant was purified through a Sep-Pak C18 reversal phase column. The radiochemical purity and in vivo stability were determined using silica gel thin layer chromatography (TLC). The biodistribution of 125I-FIAU in Kunming mice was also detected. The results showed that 125I-FIAU could be radiolabeled effectively with FTAU, with mean labeling rate being (81±0.38)% (n =5). The mean radiochemical purity of (98.01±0.40)% (n=5) was achieved after a reversal phase Sep-park column purification. 125I-FIAU was stable when incubated in normal human serum or in saline at 37°C, with a radiochemical purity 〉96% during a 0.5-24 h time period. Biological experiments exhibited rapid clearance of 125I-FIAU from the blood pool. 125I-FIAU was mostly excreted by kidneys. 125I-FIAU in myocardium dropped conspicuously after 8 h and there was hardly retention at 24 h. We were led to concluded that the new method of radioiodinization of FTAU for the preparation of 125I-FIAU is easy, highly effective and stable in vivo. The biodistribution of 125I-FIAU in Kunming mice showed it can serve as an imaging probe for myocardial reporter genes.展开更多
AIM: To investigate the ocular biodistribution and clearance of topically administered 7-taurocholic acid conjugated low-molecular weight heparin(LHT7) in a neovascularized mouse cornea using an in vivo optical ima...AIM: To investigate the ocular biodistribution and clearance of topically administered 7-taurocholic acid conjugated low-molecular weight heparin(LHT7) in a neovascularized mouse cornea using an in vivo optical imaging system. METHODS: A total of 10 eyes of 6 to 8-week-old BALB/c mice were analyzed. Corneal neovascularization(CoNV) was induced in the inferior cornea(IC) of each animal by penetrating the stroma with two interrupted sutures. The development of CoNV was verified after one week and the area of each neovascularized region was measured. A near-infrared fluorescent probe of 20 μmol/L Cy5.5 labeled LHT7(LHT7-Cy5.5) in 0.02 mL solution was topically instilled onto the cornea in the experimental group(n=5). Free-Cy5.5 of 20 μmol/L in 0.02 mL was instilled in the control group(n=5). In vivo optical images were obtained before instillation and 5 min, 2, 4, and 6 h after instillation. The intensities were separately measured at the superior cornea(SC) and the IC. RESULTS: The mean CoNV areas were 1.97±0.17 mm^2 and 1.92±0.96 mm^2 in the experimental and control groups, respectively(P=0.832). The SC remained normal in all 10 subject animals. The IC intensity of the LHT7-Cy5.5 was greater than the SC intensity at 5 min(P=0.038), 2 h(P=0.041), and 4 h(P=0.041) after application. The IC intensity fell to less than half of its initial value(42.9%±8.6%) at 6 h in the experimental group. In the control mice, here were no significant differences in the free-Cy5.5 intensity between the IC and SC. CONCLUSION: Topically administered LHT7 shows a high biodistribution in CoNV areas for 4 h and should be reapplied accordingly to maintain its effects. In vivo optical imaging can be a useful tool for evaluating the ocular biodistribution of a drug in an animal model.展开更多
[61Cu]-labeled pyruvaldehyde-bis(N-4-methylthiosemicarbazone) (61Cu-PTSM), a promising agent made for imaging blood perfusion, was produced via the natZn(p,x)61Cu nuclear reaction in a 30 MeV cyclotron, and separated ...[61Cu]-labeled pyruvaldehyde-bis(N-4-methylthiosemicarbazone) (61Cu-PTSM), a promising agent made for imaging blood perfusion, was produced via the natZn(p,x)61Cu nuclear reaction in a 30 MeV cyclotron, and separated by a two-step column chromatography method developed in our laboratory using a cation and an anion exchange resin. After 150 μA irradiation for 76 min, about 6.006 Ci of 61Cu2+ was obtained with a radiochemical separation yield of 95% and a radionuclidic purity of 99%. Cu-PTSM was prepared using an optimized method with 61 in-house synthesized PTSM ligand for radiolabeling following quality control procedures using RTLC and HPLC. The tracer is mostly incorporated in heart, kidneys and brain compared to free copper cation as a control. These are in agreement with former reports. In conclusion, [61Cu]-PTSM was prepared at the radiopharmaceutical scales with high quality and is a potential PET tracer in the perfusion study of the heart, kidney, brain and tumors.展开更多
Objective:To labelavidin(Av)or streptavidin(SA)with 153 Sm by takingadvantageof thehighbindingaffin-ityof biotinto Av or SA.Methods:A biotinderivative(DTPA-biotin)wasradiolabelledwith 153 Sm andthenboundto Av or SA.Th...Objective:To labelavidin(Av)or streptavidin(SA)with 153 Sm by takingadvantageof thehighbindingaffin-ityof biotinto Av or SA.Methods:A biotinderivative(DTPA-biotin)wasradiolabelledwith 153 Sm andthenboundto Av or SA.Thein vivo kineticsandbiodistributionof 153 Sm-labeledAv,SA andDTPA-biotinwerestudiedinratsandmice.Results:153 Sm-Avwascharacterizedby rapidclearancefromthebloodwithhighliverandrenaluptake;153 Sm-SAwas clearedfromthebloodslowlywithhighretentionintheliver,spleenandkidney,whereas 153 Sm-DTPA-biotinmetabolismwas accelerated,anditsexcretionwasmainlythroughthekidney.Conclu sion:Thebiodistributiondifferenceof SAandAvmay providean experimentalbasisfor theselectionof differentcomponentsof avidin-biotinsystemin pretagetingradioim-munoimagingandradioimmunotherapy.展开更多
Novel human interferon alpha 2b (hIFNα2b) muteins were developed by substituting cysteine residue (C) at positions 2 and 99 with aspartic acid residues (D). The mutein forms were then studied for pharmacokinetic prof...Novel human interferon alpha 2b (hIFNα2b) muteins were developed by substituting cysteine residue (C) at positions 2 and 99 with aspartic acid residues (D). The mutein forms were then studied for pharmacokinetic profile. In addition, the influence of charge on the protein structure was tested in vivo for the biodistribution pattern. Codon substitutions were performed by Polymerase Chain Reaction (PCR)-based site-directed mutagenesis on a previously constructed synthetic hIFNα2b open reading frame (ORF) cloned in pET32b expression plasmid. The result of nucleotide sequencing analysis confirmed that all codons were replaced successfully without any additional mutation. Three mutant forms of hIFNα2b ORF were overexpressed in Escherichia coli BL21 (DE3) resulted in three muteins: hIFNα2b C2D, hIFNα2b C99D, hIFNα2b C2D C99D. To follow the kinetic and localization of the mutein interferon after intravenous administration, Tc99m was used to label the proteins. In particular of elimination half-life, it was shown that hIFNα2b C2D C99D > hIFNα2bC2D > hIFNα2bC99D > wild type. hIFNα2b C2D C99D mutein showed highest blood accumulation after 30 minutes administration. Taken together, the charge of hIFNα2b seems to be responsible for the fate of hIFNα2b in vivo.展开更多
Prostate-specific membrane antigen(PSMA) is a useful target for diagnostic and therapeutic applications,and it is demonstrated that ^(68) Ga in conjugation with DKFZPSMA-617 is better than ^(68)Ga-PSMA-1 in biodistrib...Prostate-specific membrane antigen(PSMA) is a useful target for diagnostic and therapeutic applications,and it is demonstrated that ^(68) Ga in conjugation with DKFZPSMA-617 is better than ^(68)Ga-PSMA-1 in biodistribution data after 1 h,but more preclinical data are still required.In this paper,we presented the additional preclinical data for ^(68)Ga-DKFZ-PSMA-617 and relevant aspects of its production.^(68) Ga was obtained from the SnO_2-based ^(68)Ge/ ^(68) Ga generator.Optimum conditions(p H,temperature,time and ligand concentration) for ^(68)Ga-DKFZPSMA-617 preparation were studied.Radiochemical purity of the radiolabeled compound was determined by HPLC and RTLC.After stability assessments,the complex was intravenously injected into rats.HPLC and ITLC characterizations indicated that the radiopharmaceutical could be prepared with radiochemical purity of [96 % and specific activity of 308.3 TBq/mmol at the optimized conditions(p H of 3.5–4,ligand amount of 2.4 nmol,temperature of90–95 C and reaction time of 10 min).Also,the biodistribution data showed no undesirable uptake in nontarget organs at any interval after injection.In fact,the activity is cleaned from blood and excreted rapidly via the kidneys.Generally,this compound can be considered as a wellestablished PET imaging agent.展开更多
67Ga-EDTMP was synthesized in a single step by adding 67GaCl3 to EDTMP solution. Dependences ofthe radiolabeling yield of 67Ga-EDTMP on EDTMP concentration, pH and reaction time were examined. Under theoptimum conditi...67Ga-EDTMP was synthesized in a single step by adding 67GaCl3 to EDTMP solution. Dependences ofthe radiolabeling yield of 67Ga-EDTMP on EDTMP concentration, pH and reaction time were examined. Under theoptimum conditions, the radiolabeling yield of 67Ga-EDTMP was more than 97%. A biodistribution experiment inmice showed that 67Ga-EDTMP was mainly absorbed by skeleton and reached 13.25% at 0.5 h after injecting, thenkept a high level in 72 h with a maximum value of 16.82% at 48 h. The results suggest that 67Ga-EDTMP might be apotential bone pain palliation radiopharmaceutical due to its high skeletal uptake, rapid blood clearance and relativelylow soft-tissue absorption. But further work must be done to determine whether 67Ga-EDTMP is useful in thetreatment of painful osseous metastases.展开更多
The cyclic peptide YG5 and the t-butyloxycarbonyl(Boc)-modified analog(Boc-YG5) were labeled with radioiodine.The radiochemical purity of 131I-YG5 or 131I-Boc-YG5 was almost 100% after purification by RP-HPLC.Biodistr...The cyclic peptide YG5 and the t-butyloxycarbonyl(Boc)-modified analog(Boc-YG5) were labeled with radioiodine.The radiochemical purity of 131I-YG5 or 131I-Boc-YG5 was almost 100% after purification by RP-HPLC.Biodistribution in BALB/C nude mice bearing MCF-7 tumor was measured.After t-butyloxycarbonyl(Boc)-modification,the 131I-Boc-YG5 was quite resistant to deiodination in vivo,resulting in negligible radioactivity accumulation in thyroid.The radiotracer clearance in tumor became faster,the absolute tumor uptake decreased for 131I-Boc-YG5,but the tumor-to-tissue uptake ratios increased.The uptake ratios of tumor to muscle,blood,heart,and lung at 1 h post injection reached 4.73,1.70,4.09 and 1.70,respectively.It is demonstrated that Boc-group is an effective prosthetic one to prevent deiodination in vivo and improve tumor imaging for radioiodinated NGR.展开更多
In order to prepare a specific melanocortin type 2 receptor (MC2R) ligand, β1-24-corticotrophin was prepared in one-step reaction with [18F] SFB and β-1-24-corticotrophin pharmaceutical solution (1 mg/mL, pH=6.5). [...In order to prepare a specific melanocortin type 2 receptor (MC2R) ligand, β1-24-corticotrophin was prepared in one-step reaction with [18F] SFB and β-1-24-corticotrophin pharmaceutical solution (1 mg/mL, pH=6.5). [18F]SFB was prepared in a semi-automated module in two steps with an overall radiochemical yield of 47% to EOB (not-decay corrected) in 90 min. The 18F-labeled intermediates and 18F-labeled peptide was checked by RTLC and HPLC. The results show that the radiochemical purity is >95% and the yield to EOB (not-decay corrected) is 29% for final 18F-labeled peptide at optimized conditions. Preliminary in vivo studies in normal mice were performed to determine biodistribution of the 18F-labeled peptide for 150 min. The results show that the major tracer uptake is consistent with the natural distribution of MC2R receptors in mammals. Testes/blood and testes/muscle ratios for 18F-labeled peptide at 150 min were 184 and 1.56, respectively, and adipocyte/blood and adipocyte/muscle ratios at 120 min were 221 and 142, respectively. The data support the specific receptor binding of the radiolabeled peptide as reported for MC2R receptor accumulation in adipocytes and testes and demonstrates the retention of biological activity of the peptide. This tracer can be used in detection of MC2R distribution in malignancies and sex organ diseases.展开更多
A comparison of ^99mTc-CQDO and ^99mTc-CQDO-MeB has been made for biodistribution and pharmacokinetics,^99mTc-CQDO and its adducts of methaneboronic acid^99mTc-CQDO-MeB were prepared by the reduction of Na ^99mTcO4 wi...A comparison of ^99mTc-CQDO and ^99mTc-CQDO-MeB has been made for biodistribution and pharmacokinetics,^99mTc-CQDO and its adducts of methaneboronic acid^99mTc-CQDO-MeB were prepared by the reduction of Na ^99mTcO4 with SnCl2.2H2O in aqueous solution,Radiochemical purity of ^99mTc-CQDO and ^99mTc-CQDO-MeB determined by TLC were over 95% after extraction.Biodistributions of ^99mTc-CQDO and ^99mTc-CQDOMeB in mice demonstrated that both of them could be easily absorbed by myocardium,and the peak uptake of each were 10.83±2.2% ID/g and 11.84±1.69%ID/g,respectively.^99mTc-CQDO showed rapid clearance from myocardial tissue while ^99mTc-CQDO-MeB had long retention in heart muscle.The myocardial uptake of ^99mTc-CQDO was only 5.88±1.66%/g at 10min and the uptake of ^99mTc-CQDO-MeB was 7.42±0.17%ID/g at 60min.The elimination of each from blood has a biexponential pattern.the first T1/2 is 1.38 and 1.5min,pespectively.The partition coefficient of ^99mTc-CQDO and ^99mTc-CQDO-MeB were 20 and 25 at pH 7.40,respectively.展开更多
This work was to investigate the pharmacologic characteristics of 18F-FECNT (2β-carbomethoxy-3β- (4-chlorophenyl)-8-(2-[18F]fluoroethyl)nortropane) as a dopamine transporter (DAT) PET imaging agent. Its partition co...This work was to investigate the pharmacologic characteristics of 18F-FECNT (2β-carbomethoxy-3β- (4-chlorophenyl)-8-(2-[18F]fluoroethyl)nortropane) as a dopamine transporter (DAT) PET imaging agent. Its partition coefficients were determined in n-octanol and phosphate buffer (PB) (pH 7.0 and pH 7.4). 6-Hydroxydopamine (6-OHDA) left-sided lesioned Parkinsonian rats were established and validated by rotational behavior tests. Biodistribution in vivo in mice, autoradiography in normal and hemi-Parkinsonian rat brains, and toxicity test were performed. The results showed that partition coefficients were 34.14 (pH 7.0) and 56.41 (pH 7.4), respectively. Biodistribution exhibited rapid uptake and favorable retention in the mice brains. The major radioactivity was metabolized by the hepatic system. The autoradiography showed that 18F-FECNT was highly concentrated in striatum, and that the left and the right striatal uptake were symmetrical in normal SD rat brains. In left-sided lesioned PD rat brains, the striatal uptake of 18F-FECNT bilaterally decreased in comparison with normal rats. No significant uptake was visible in the 6-OHDA lesioned-sided striatal areas. The results demonstrated that 18F-FECNT binds to DAT was specific. Toxicity trial displayed that the acceptable dose per kilogram to mice was 625 times greater than that to human. These indicate that 18F-FECNT is a potentially safe and useful DAT PET imaging agent in the brain.展开更多
No-carrier-added 6-[^18F] fluoro-L-DOPA(6-FDOPA) was synthesized via a multistep procedure from a commercial available precursor,6-nitroveratraldehyde,The total synthesis time was 75min,with a radiochemical yield of (...No-carrier-added 6-[^18F] fluoro-L-DOPA(6-FDOPA) was synthesized via a multistep procedure from a commercial available precursor,6-nitroveratraldehyde,The total synthesis time was 75min,with a radiochemical yield of (10±3)%,high radiochemical purity(>99%) and high enantiomeric purity(>95%).The biodistributions of 6-FDOPA in normal and unilateral PD model rats were measured.The results from normal rats showed the expected high concentration of radioactivity in striatum and low distrbutions in cerebrum,cortex and cerebellum.The ration of the radioactivity in striatum to cerebellum reached a peak value(5.9) at 60 min.In unilateral PD model rate.whose substania nigra of the right side had been damaged by pre-treated with 6-OHDA,the radioactive concentration in striatum of the damaged side was significantly lower than that of the undamaged side or that of both sides in striatum of control groups.展开更多
The pharmacologic characteristics of ^(99)Tc^m-N-ethyl-N_2S_2-memantine,an NMDA receptor imaging agent,was investigated.It was prepared by a one-step reaction from N-ethyl-N_2S_2-memantine.The affinity and specificity...The pharmacologic characteristics of ^(99)Tc^m-N-ethyl-N_2S_2-memantine,an NMDA receptor imaging agent,was investigated.It was prepared by a one-step reaction from N-ethyl-N_2S_2-memantine.The affinity and specificity were determined by radio-ligand receptor binding assay(RRA).Biodistribution in vivo in mice was performed.The results showed that ^(99)Tc^m-N-ethyl-N_2S_2-memantine bound to a single site on NMDA receptor with a K_d of 584.32 nmol/L and a B_(max)of 267.05 nmol/mg.A competitive analysis showed that such specific binding could be inhibited by specific inhibitors of NMDA receptor,such as ketamine and(+)-MK-801.The biodistribution exhibited rapid uptake and favorable retention in mice brains.The major radioactivity was metabolized by the hepatic system.A two-compartment model of C=4.49e^(-0.083t)+ 1.42e^(-0.0016t)was established,and the half life was 8.35 min in blood.In conclusion,the new radio-ligand ^(99)Tc^m-N-ethyl-N_2S_2-Memantine has a moderate affinity and specific binding to NMDA receptor,and can easily cross the blood-brain barrier(BBB).Therefore,it may be a potential NMDA receptor imaging agent.展开更多
基金the National Natural Science Foundation of China(Nos.81402640,81502816)the Natural Science Foundation of Hubei Province(No.2014CFB406)+1 种基金the Health and Family Planning Commission of Wuhan City(No.WX15B23)Training Plan for Young and Middleaged Backbone Talents in Wuhan[No.2014(77)].
文摘Biodistribution and toxicity assessment are critical for safe clinical use of newly developed medicines.Superparamagnetic iron oxide nanoparticles (SPION)are effective carriers for targeted drug delivery.This study aimed to examine the toxicity and biodistribution of SPION coated with polyethylenimine (PEI)(SPION-PEI)designed for small interfering RNA (siRNA) delivery both in vitro and in vivo.SPION-PEI/siRNA complexes were prepared at different weight ratios.Cytotoxic effects of SPION-PEI/siRNA on HSC-T6 cell viability were determined by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT).Rats were divided into three groups:a control group,a normal-saline group and a SPION-PEI/siRNA group.After a single intravenous injection,in vivo nanoparticle biodistribution and accumulation were evaluated by Prussian blue staining in the heart,liver,spleen,lung and kidney 8 h,24 h,and 7 days after the injection.Their distribution was histologically studied at the three time points by measuring ironpositive areas (μm2)in organ sections stained with Prussian blue.The same organs were analyzed by H&E staining for any possible histopathological changes.Furthermore,biochemical indexes such as alanine amino transaminase (ALT),aspartate transaminase (AST),blood urea nitrogen (BUN)and creatinine (CREA)were also assessed at all experimental time points.Electrophoresis exhibited that the SPION-PEI could retard siRNA altogether at weight ratios above 4.MTT assay showed that SPION-PEI loaded with siRNA had low cytotoxicity.In vivo study revealed that the liver and spleen were the major sites of SPION-PEI/siRNA deposition.The iron content was significantly increased in the liver and spleen,peaking 24 h after intravenous injection and then declining gradually.No evidence was found of irreversible histopathological damage to any of the organs tested.These results suggested that most SPION-PEI/siRNA complexes were distributed in the liver and spleen,which might be the target organs of SPION-PEI/siRNA complexes.SPION- PEI/siRNA may serve as in vivo carrier for biomedical medicines.
基金Supported by the National Natural Science Foundation of China (No.20801024)Wu Jieping Medical Found(No.32067500615)
文摘A novel zoledronic acid derivative,1-hydroxy-2-(2-propyl-1H-imidazol-1-yl)ethane-1,1-diyldiphosphonic acid (PIDP), was synthesized by three-step reactions from 2-propyl-1H-imidazole. It was labeled with 99Tcm in conditions of 0.1 mg SnCl2.2H2O at pH 6.0 and 99TcmO4? in aqueous solution for 20 min at room temperature. The labeling yield and radiochemical purity of 99Tcm-PIDP are both higher than 95%. The biodistribution results show that the bone uptake is up to 8.47% ID/g which is the maximum of bone uptake at 30 min after injection of 99Tcm-PIDP in mice. The pharmacokinetic parameters can be estimated from the exponential equation of C=59.565e-11.307t+2.069e-1.211t. The clear bone image of rabbit was obtained at 120 min after injection of 99Tcm-PIDP. The results indicate that 99Tcm-PIDP has highly selective uptake in the skeletal and low uptake, rapid clearance in soft tissues, so it would be a potential novel bone imaging agent.
文摘99mTc-HMIBP, a new bone-imaging agent, was prepared by the reduction of 99mTc-pertechnetate in the presence of SnCl2?2H2O. The effects of the amounts of SnCl2?2H2O and HMIBP and the pH value on the labeling yield and radiochemical purity of 99mTc-HMIBP were investigated. When the amounts of SnCl2?2H2O and HMIBP were more than 10 μg and 2.5 mg, respectively, the pH value was between 2 and 7, and the labeling reaction contin- ued for 10 min, both labeling yield and radiochemical purity of 99mTc-HMIBP were more than 90%. The biodistribu- tion in rats and bone scan in rabbits were also studied. The results showed that the bone uptake is up to 7.94%ID/g at 30 min after injection of 99mTc-HMIBP, bone-to-muscle and bone-to-blood uptake ratios were 20.89 and 16.89, re- spectively. The clear bone image was obtained at 120 min after injection of 99mTc-HMIBP and clearance in soft tissue was visible. All of the above-mentioned results suggested that 99mTc-HMIBP may be a potential bone-imaging agent.
文摘This work was conducted for radiolabeling of an anticancer antibiotic, i.e. doxorubicin with 61Cu for production of possible tracer used in PET oncology. 61Cu was prepared with natural zinc target and 22 MeV150 μA protons via natZn(p, xn)61Cu reaction with a yield of 123.2 MBq·μA-1·h-1. Optimization reactions were performed for pH, temperature and concentration. Biodistribution of the tracer was studied in normal and fibrosarcoma bearing mice. At the optimized conditions, ITLC showed that radiochemical purity was over 97% with a specific activity of 2.22× 103MBq ·mmol-1·L-1. This was kept unchanged even with presence of human serum as well as room temperature for 5 h. Biodistribution of the tracer in fibrosarcoma bearing mice demonstrated significant tumor uptake after 2 h. This tracer can be used in the detection of various tumors responding to doxorubicin chemotherapy using PET scan and/or determination of tumor therapy response to doxorubicin chemotherapy.
基金sponsored by the grants from the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the Ministry of Education of China (No. [2008]890)the National Natural Science Foundation of China (Nos. 30872652, 30830041, 30772208)Fund of Doctoral Programs for New College Teachers of the Ministry of Education (No. 20070487160)
文摘In this study, a novel technique for the preparation of 125I-5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FIAU) was developed, 125I-FIAU biodistribution profile was detected in Kunming mice and the possibility of using FTAU radio-labeling for reporter gene imaging was explored. 5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FTAU) was labeled with radioiodine (125I). A rotary evaporation method was used to remove excess methanol. The reactant was purified through a Sep-Pak C18 reversal phase column. The radiochemical purity and in vivo stability were determined using silica gel thin layer chromatography (TLC). The biodistribution of 125I-FIAU in Kunming mice was also detected. The results showed that 125I-FIAU could be radiolabeled effectively with FTAU, with mean labeling rate being (81±0.38)% (n =5). The mean radiochemical purity of (98.01±0.40)% (n=5) was achieved after a reversal phase Sep-park column purification. 125I-FIAU was stable when incubated in normal human serum or in saline at 37°C, with a radiochemical purity 〉96% during a 0.5-24 h time period. Biological experiments exhibited rapid clearance of 125I-FIAU from the blood pool. 125I-FIAU was mostly excreted by kidneys. 125I-FIAU in myocardium dropped conspicuously after 8 h and there was hardly retention at 24 h. We were led to concluded that the new method of radioiodinization of FTAU for the preparation of 125I-FIAU is easy, highly effective and stable in vivo. The biodistribution of 125I-FIAU in Kunming mice showed it can serve as an imaging probe for myocardial reporter genes.
基金Supported by a grant(No.2016-7026)from the Asan Institute for Life Science,Seoul,Republic of Korea
文摘AIM: To investigate the ocular biodistribution and clearance of topically administered 7-taurocholic acid conjugated low-molecular weight heparin(LHT7) in a neovascularized mouse cornea using an in vivo optical imaging system. METHODS: A total of 10 eyes of 6 to 8-week-old BALB/c mice were analyzed. Corneal neovascularization(CoNV) was induced in the inferior cornea(IC) of each animal by penetrating the stroma with two interrupted sutures. The development of CoNV was verified after one week and the area of each neovascularized region was measured. A near-infrared fluorescent probe of 20 μmol/L Cy5.5 labeled LHT7(LHT7-Cy5.5) in 0.02 mL solution was topically instilled onto the cornea in the experimental group(n=5). Free-Cy5.5 of 20 μmol/L in 0.02 mL was instilled in the control group(n=5). In vivo optical images were obtained before instillation and 5 min, 2, 4, and 6 h after instillation. The intensities were separately measured at the superior cornea(SC) and the IC. RESULTS: The mean CoNV areas were 1.97±0.17 mm^2 and 1.92±0.96 mm^2 in the experimental and control groups, respectively(P=0.832). The SC remained normal in all 10 subject animals. The IC intensity of the LHT7-Cy5.5 was greater than the SC intensity at 5 min(P=0.038), 2 h(P=0.041), and 4 h(P=0.041) after application. The IC intensity fell to less than half of its initial value(42.9%±8.6%) at 6 h in the experimental group. In the control mice, here were no significant differences in the free-Cy5.5 intensity between the IC and SC. CONCLUSION: Topically administered LHT7 shows a high biodistribution in CoNV areas for 4 h and should be reapplied accordingly to maintain its effects. In vivo optical imaging can be a useful tool for evaluating the ocular biodistribution of a drug in an animal model.
文摘[61Cu]-labeled pyruvaldehyde-bis(N-4-methylthiosemicarbazone) (61Cu-PTSM), a promising agent made for imaging blood perfusion, was produced via the natZn(p,x)61Cu nuclear reaction in a 30 MeV cyclotron, and separated by a two-step column chromatography method developed in our laboratory using a cation and an anion exchange resin. After 150 μA irradiation for 76 min, about 6.006 Ci of 61Cu2+ was obtained with a radiochemical separation yield of 95% and a radionuclidic purity of 99%. Cu-PTSM was prepared using an optimized method with 61 in-house synthesized PTSM ligand for radiolabeling following quality control procedures using RTLC and HPLC. The tracer is mostly incorporated in heart, kidneys and brain compared to free copper cation as a control. These are in agreement with former reports. In conclusion, [61Cu]-PTSM was prepared at the radiopharmaceutical scales with high quality and is a potential PET tracer in the perfusion study of the heart, kidney, brain and tumors.
文摘Objective:To labelavidin(Av)or streptavidin(SA)with 153 Sm by takingadvantageof thehighbindingaffin-ityof biotinto Av or SA.Methods:A biotinderivative(DTPA-biotin)wasradiolabelledwith 153 Sm andthenboundto Av or SA.Thein vivo kineticsandbiodistributionof 153 Sm-labeledAv,SA andDTPA-biotinwerestudiedinratsandmice.Results:153 Sm-Avwascharacterizedby rapidclearancefromthebloodwithhighliverandrenaluptake;153 Sm-SAwas clearedfromthebloodslowlywithhighretentionintheliver,spleenandkidney,whereas 153 Sm-DTPA-biotinmetabolismwas accelerated,anditsexcretionwasmainlythroughthekidney.Conclu sion:Thebiodistributiondifferenceof SAandAvmay providean experimentalbasisfor theselectionof differentcomponentsof avidin-biotinsystemin pretagetingradioim-munoimagingandradioimmunotherapy.
文摘Novel human interferon alpha 2b (hIFNα2b) muteins were developed by substituting cysteine residue (C) at positions 2 and 99 with aspartic acid residues (D). The mutein forms were then studied for pharmacokinetic profile. In addition, the influence of charge on the protein structure was tested in vivo for the biodistribution pattern. Codon substitutions were performed by Polymerase Chain Reaction (PCR)-based site-directed mutagenesis on a previously constructed synthetic hIFNα2b open reading frame (ORF) cloned in pET32b expression plasmid. The result of nucleotide sequencing analysis confirmed that all codons were replaced successfully without any additional mutation. Three mutant forms of hIFNα2b ORF were overexpressed in Escherichia coli BL21 (DE3) resulted in three muteins: hIFNα2b C2D, hIFNα2b C99D, hIFNα2b C2D C99D. To follow the kinetic and localization of the mutein interferon after intravenous administration, Tc99m was used to label the proteins. In particular of elimination half-life, it was shown that hIFNα2b C2D C99D > hIFNα2bC2D > hIFNα2bC99D > wild type. hIFNα2b C2D C99D mutein showed highest blood accumulation after 30 minutes administration. Taken together, the charge of hIFNα2b seems to be responsible for the fate of hIFNα2b in vivo.
文摘Prostate-specific membrane antigen(PSMA) is a useful target for diagnostic and therapeutic applications,and it is demonstrated that ^(68) Ga in conjugation with DKFZPSMA-617 is better than ^(68)Ga-PSMA-1 in biodistribution data after 1 h,but more preclinical data are still required.In this paper,we presented the additional preclinical data for ^(68)Ga-DKFZ-PSMA-617 and relevant aspects of its production.^(68) Ga was obtained from the SnO_2-based ^(68)Ge/ ^(68) Ga generator.Optimum conditions(p H,temperature,time and ligand concentration) for ^(68)Ga-DKFZPSMA-617 preparation were studied.Radiochemical purity of the radiolabeled compound was determined by HPLC and RTLC.After stability assessments,the complex was intravenously injected into rats.HPLC and ITLC characterizations indicated that the radiopharmaceutical could be prepared with radiochemical purity of [96 % and specific activity of 308.3 TBq/mmol at the optimized conditions(p H of 3.5–4,ligand amount of 2.4 nmol,temperature of90–95 C and reaction time of 10 min).Also,the biodistribution data showed no undesirable uptake in nontarget organs at any interval after injection.In fact,the activity is cleaned from blood and excreted rapidly via the kidneys.Generally,this compound can be considered as a wellestablished PET imaging agent.
基金the National Natural Science Foundation of China(No.1 9975066)
文摘67Ga-EDTMP was synthesized in a single step by adding 67GaCl3 to EDTMP solution. Dependences ofthe radiolabeling yield of 67Ga-EDTMP on EDTMP concentration, pH and reaction time were examined. Under theoptimum conditions, the radiolabeling yield of 67Ga-EDTMP was more than 97%. A biodistribution experiment inmice showed that 67Ga-EDTMP was mainly absorbed by skeleton and reached 13.25% at 0.5 h after injecting, thenkept a high level in 72 h with a maximum value of 16.82% at 48 h. The results suggest that 67Ga-EDTMP might be apotential bone pain palliation radiopharmaceutical due to its high skeletal uptake, rapid blood clearance and relativelylow soft-tissue absorption. But further work must be done to determine whether 67Ga-EDTMP is useful in thetreatment of painful osseous metastases.
基金Support by National Natural Science Foundation of China (No. 20771011 and 21071010)the Ministry of Science and Technology of China (No. 2006CB705700)
文摘The cyclic peptide YG5 and the t-butyloxycarbonyl(Boc)-modified analog(Boc-YG5) were labeled with radioiodine.The radiochemical purity of 131I-YG5 or 131I-Boc-YG5 was almost 100% after purification by RP-HPLC.Biodistribution in BALB/C nude mice bearing MCF-7 tumor was measured.After t-butyloxycarbonyl(Boc)-modification,the 131I-Boc-YG5 was quite resistant to deiodination in vivo,resulting in negligible radioactivity accumulation in thyroid.The radiotracer clearance in tumor became faster,the absolute tumor uptake decreased for 131I-Boc-YG5,but the tumor-to-tissue uptake ratios increased.The uptake ratios of tumor to muscle,blood,heart,and lung at 1 h post injection reached 4.73,1.70,4.09 and 1.70,respectively.It is demonstrated that Boc-group is an effective prosthetic one to prevent deiodination in vivo and improve tumor imaging for radioiodinated NGR.
文摘In order to prepare a specific melanocortin type 2 receptor (MC2R) ligand, β1-24-corticotrophin was prepared in one-step reaction with [18F] SFB and β-1-24-corticotrophin pharmaceutical solution (1 mg/mL, pH=6.5). [18F]SFB was prepared in a semi-automated module in two steps with an overall radiochemical yield of 47% to EOB (not-decay corrected) in 90 min. The 18F-labeled intermediates and 18F-labeled peptide was checked by RTLC and HPLC. The results show that the radiochemical purity is >95% and the yield to EOB (not-decay corrected) is 29% for final 18F-labeled peptide at optimized conditions. Preliminary in vivo studies in normal mice were performed to determine biodistribution of the 18F-labeled peptide for 150 min. The results show that the major tracer uptake is consistent with the natural distribution of MC2R receptors in mammals. Testes/blood and testes/muscle ratios for 18F-labeled peptide at 150 min were 184 and 1.56, respectively, and adipocyte/blood and adipocyte/muscle ratios at 120 min were 221 and 142, respectively. The data support the specific receptor binding of the radiolabeled peptide as reported for MC2R receptor accumulation in adipocytes and testes and demonstrates the retention of biological activity of the peptide. This tracer can be used in detection of MC2R distribution in malignancies and sex organ diseases.
文摘A comparison of ^99mTc-CQDO and ^99mTc-CQDO-MeB has been made for biodistribution and pharmacokinetics,^99mTc-CQDO and its adducts of methaneboronic acid^99mTc-CQDO-MeB were prepared by the reduction of Na ^99mTcO4 with SnCl2.2H2O in aqueous solution,Radiochemical purity of ^99mTc-CQDO and ^99mTc-CQDO-MeB determined by TLC were over 95% after extraction.Biodistributions of ^99mTc-CQDO and ^99mTc-CQDOMeB in mice demonstrated that both of them could be easily absorbed by myocardium,and the peak uptake of each were 10.83±2.2% ID/g and 11.84±1.69%ID/g,respectively.^99mTc-CQDO showed rapid clearance from myocardial tissue while ^99mTc-CQDO-MeB had long retention in heart muscle.The myocardial uptake of ^99mTc-CQDO was only 5.88±1.66%/g at 10min and the uptake of ^99mTc-CQDO-MeB was 7.42±0.17%ID/g at 60min.The elimination of each from blood has a biexponential pattern.the first T1/2 is 1.38 and 1.5min,pespectively.The partition coefficient of ^99mTc-CQDO and ^99mTc-CQDO-MeB were 20 and 25 at pH 7.40,respectively.
基金Supported by the National Natural Science Foundation of P. R. China (30570518)High Technology Research and Development Program of Jiangsu Province of China (BG2007603)Science Foundation of Health Department of Jiangsu Province of China (H200401)
文摘This work was to investigate the pharmacologic characteristics of 18F-FECNT (2β-carbomethoxy-3β- (4-chlorophenyl)-8-(2-[18F]fluoroethyl)nortropane) as a dopamine transporter (DAT) PET imaging agent. Its partition coefficients were determined in n-octanol and phosphate buffer (PB) (pH 7.0 and pH 7.4). 6-Hydroxydopamine (6-OHDA) left-sided lesioned Parkinsonian rats were established and validated by rotational behavior tests. Biodistribution in vivo in mice, autoradiography in normal and hemi-Parkinsonian rat brains, and toxicity test were performed. The results showed that partition coefficients were 34.14 (pH 7.0) and 56.41 (pH 7.4), respectively. Biodistribution exhibited rapid uptake and favorable retention in the mice brains. The major radioactivity was metabolized by the hepatic system. The autoradiography showed that 18F-FECNT was highly concentrated in striatum, and that the left and the right striatal uptake were symmetrical in normal SD rat brains. In left-sided lesioned PD rat brains, the striatal uptake of 18F-FECNT bilaterally decreased in comparison with normal rats. No significant uptake was visible in the 6-OHDA lesioned-sided striatal areas. The results demonstrated that 18F-FECNT binds to DAT was specific. Toxicity trial displayed that the acceptable dose per kilogram to mice was 625 times greater than that to human. These indicate that 18F-FECNT is a potentially safe and useful DAT PET imaging agent in the brain.
基金Supported by the National Nature Sciences Foundation(10075073)
文摘No-carrier-added 6-[^18F] fluoro-L-DOPA(6-FDOPA) was synthesized via a multistep procedure from a commercial available precursor,6-nitroveratraldehyde,The total synthesis time was 75min,with a radiochemical yield of (10±3)%,high radiochemical purity(>99%) and high enantiomeric purity(>95%).The biodistributions of 6-FDOPA in normal and unilateral PD model rats were measured.The results from normal rats showed the expected high concentration of radioactivity in striatum and low distrbutions in cerebrum,cortex and cerebellum.The ration of the radioactivity in striatum to cerebellum reached a peak value(5.9) at 60 min.In unilateral PD model rate.whose substania nigra of the right side had been damaged by pre-treated with 6-OHDA,the radioactive concentration in striatum of the damaged side was significantly lower than that of the undamaged side or that of both sides in striatum of control groups.
基金Supported by National Natural Science Foundation(No30770602)Jiangsu Natural Science Foundation(No BK2008111)
文摘The pharmacologic characteristics of ^(99)Tc^m-N-ethyl-N_2S_2-memantine,an NMDA receptor imaging agent,was investigated.It was prepared by a one-step reaction from N-ethyl-N_2S_2-memantine.The affinity and specificity were determined by radio-ligand receptor binding assay(RRA).Biodistribution in vivo in mice was performed.The results showed that ^(99)Tc^m-N-ethyl-N_2S_2-memantine bound to a single site on NMDA receptor with a K_d of 584.32 nmol/L and a B_(max)of 267.05 nmol/mg.A competitive analysis showed that such specific binding could be inhibited by specific inhibitors of NMDA receptor,such as ketamine and(+)-MK-801.The biodistribution exhibited rapid uptake and favorable retention in mice brains.The major radioactivity was metabolized by the hepatic system.A two-compartment model of C=4.49e^(-0.083t)+ 1.42e^(-0.0016t)was established,and the half life was 8.35 min in blood.In conclusion,the new radio-ligand ^(99)Tc^m-N-ethyl-N_2S_2-Memantine has a moderate affinity and specific binding to NMDA receptor,and can easily cross the blood-brain barrier(BBB).Therefore,it may be a potential NMDA receptor imaging agent.