The complex 99m TcN CPDTC(CPDTC: N cyclopropyl dithiocarbamate trihydrate) is synthesized through ligand exchange reaction. The two step procedure involves the initial reaction of 99m TcO - 4 with succinic dihydrazide...The complex 99m TcN CPDTC(CPDTC: N cyclopropyl dithiocarbamate trihydrate) is synthesized through ligand exchange reaction. The two step procedure involves the initial reaction of 99m TcO - 4 with succinic dihydrazide(SDH) as a donor of nitrido ligand(N 3- ) in the presence of stannous chloride dihydrate as reducing agent and propylenediamine tetraacetic acid(PDTA) as complex agent, followed by the addition of sodium N cyclopropyl dithiocarbamate trihydrate. The radiochemical purity(RCP) of the product is over 90% as measured by thin layer chromatography(TLC). It is stable over 6 h at room temperature. Its partition coefficient indicates it is a good lipophilic complex. The biodistribution results in mice indicate that 99m TcN CPDTC is significantly retained into the brain. The brain uptake(%, ID/g) is 4.64, 3 54 and 2.59 and the brain/blood ratio is 1.08, 1.27 and 1.28 at 5, 30 and 60 min post injection respectively. These results suggest potential usefulness of the complex as a brain perfusion imaging agent.展开更多
Chemotherapy is the first-line treatment for cancer, but its systemic toxicity can be severe. Tumorselective prodrug activation offers promising opportunities to reduce systemic toxicity. Here, we present a strategy f...Chemotherapy is the first-line treatment for cancer, but its systemic toxicity can be severe. Tumorselective prodrug activation offers promising opportunities to reduce systemic toxicity. Here, we present a strategy for activating prodrugs using radiopharmaceuticals. This strategy enables the targeted release of chemotherapeutic agents due to the high tumor-targeting capability of radiopharmaceuticals. [^(18)F]FDG(2-[^(18)F]-fluoro-2-deoxy-D-glucose), one of the most widely used radiopharmaceuticals in clinics, can trigger Pt(IV) complex for controlled release of axial ligands in tumors, it might be mediated by hydrated electrons generated by water radiolysis resulting from the decay of radionuclide18F. Its application offers the controlled release of fluorogenic probes and prodrugs in living cells and tumor-bearing mice. Of note,an OxaliPt(IV) linker is designed to construct an [^(18)F]FDG-activated antibody-drug conjugate(Pt-ADC).Sequential injection of Pt-ADC and [^(18)F]FDG efficiently releases the toxin in the tumor and remarkably suppresses the tumor growth. Radiotherapy is booming as a perturbing tool for prodrug activation,and we find that [^(18)F]FDG is capable of deprotecting various radiotherapy-removable protecting groups(RPGs). Our results suggest that tumor-selective radiopharmaceutical may function as a trigger, for developing innovative prodrug activation strategies with enhanced tumor selectivity.展开更多
Polyamine metabolism dysregulation is a hallmark of many cancers,offering a promising avenue for early tumor theranostics.This study presents the development of a nuclear probe derived from spermidine(SPM)for dual-pur...Polyamine metabolism dysregulation is a hallmark of many cancers,offering a promising avenue for early tumor theranostics.This study presents the development of a nuclear probe derived from spermidine(SPM)for dual-purpose tumor PET imaging and internal radiation therapy.The probe,radiolabeled with either[68Ga]Ga for diagnostic applications or[177Lu]Lu for therapeutic use,was synthesized with exceptional purity,stability,and specific activity.Extensive testing involving 12 different tumor cell lines revealed remarkable specificity towards B16 melanoma cells,showcasing outstanding tumor localization and target-to-non-target ratio.Mechanistic investigations employing polyamines,non-labeled precursor,and polyamine transport system(PTS)inhibitor,consistently affirmed the probe?s targetability through recognition of the PTS.Notably,while previous reports indicated PTS upregulation in various tumor types for targeted therapy,this study observed no positive signals,highlighting a concentration-dependent discrepancy between targeting for therapy and diagnosis.Furthermore,when labeled with[177Lu],the probe demonstrated its therapeutic potential by effectively controlling tumor growth and extending mouse survival.Investigations into biodistribution,excretion,and biosafety in healthy humans laid a robust foundation for clinical translation.This study introduces a versatile SPM-based nuclear probe with applications in precise tumor theranostics,offering promising prospects for clinical implementation.展开更多
文摘The complex 99m TcN CPDTC(CPDTC: N cyclopropyl dithiocarbamate trihydrate) is synthesized through ligand exchange reaction. The two step procedure involves the initial reaction of 99m TcO - 4 with succinic dihydrazide(SDH) as a donor of nitrido ligand(N 3- ) in the presence of stannous chloride dihydrate as reducing agent and propylenediamine tetraacetic acid(PDTA) as complex agent, followed by the addition of sodium N cyclopropyl dithiocarbamate trihydrate. The radiochemical purity(RCP) of the product is over 90% as measured by thin layer chromatography(TLC). It is stable over 6 h at room temperature. Its partition coefficient indicates it is a good lipophilic complex. The biodistribution results in mice indicate that 99m TcN CPDTC is significantly retained into the brain. The brain uptake(%, ID/g) is 4.64, 3 54 and 2.59 and the brain/blood ratio is 1.08, 1.27 and 1.28 at 5, 30 and 60 min post injection respectively. These results suggest potential usefulness of the complex as a brain perfusion imaging agent.
基金was Beijing Municipal Natural Science Foundation (Z200018)National Natural Science Foundation of China (22225603)+2 种基金Ministry of Science and Technology of the People’s Republic of China (2021YFA1601400)Program of the Local Science and Technology Development (Gansu Province) Guided by Central Government (YDZX20216200001201)Changping Laboratory, and the Central Guidance for Local Science and Technology Development Projects (202138-03)。
文摘Chemotherapy is the first-line treatment for cancer, but its systemic toxicity can be severe. Tumorselective prodrug activation offers promising opportunities to reduce systemic toxicity. Here, we present a strategy for activating prodrugs using radiopharmaceuticals. This strategy enables the targeted release of chemotherapeutic agents due to the high tumor-targeting capability of radiopharmaceuticals. [^(18)F]FDG(2-[^(18)F]-fluoro-2-deoxy-D-glucose), one of the most widely used radiopharmaceuticals in clinics, can trigger Pt(IV) complex for controlled release of axial ligands in tumors, it might be mediated by hydrated electrons generated by water radiolysis resulting from the decay of radionuclide18F. Its application offers the controlled release of fluorogenic probes and prodrugs in living cells and tumor-bearing mice. Of note,an OxaliPt(IV) linker is designed to construct an [^(18)F]FDG-activated antibody-drug conjugate(Pt-ADC).Sequential injection of Pt-ADC and [^(18)F]FDG efficiently releases the toxin in the tumor and remarkably suppresses the tumor growth. Radiotherapy is booming as a perturbing tool for prodrug activation,and we find that [^(18)F]FDG is capable of deprotecting various radiotherapy-removable protecting groups(RPGs). Our results suggest that tumor-selective radiopharmaceutical may function as a trigger, for developing innovative prodrug activation strategies with enhanced tumor selectivity.
基金supported by the Science and Technology Innovation Team Talent Project of Hunan Province(No.2021RC4056)the clinical research foundation of the National Clinical Research Center for Geriatric Diseases(XIANGYA)(No.2020LNJJ01)+1 种基金the Natural Science Foundation of Hunan Province in China(No.2021JJ20084)the Science and Technology Innovation Program of Hunan Province(No.2021RC3020)。
文摘Polyamine metabolism dysregulation is a hallmark of many cancers,offering a promising avenue for early tumor theranostics.This study presents the development of a nuclear probe derived from spermidine(SPM)for dual-purpose tumor PET imaging and internal radiation therapy.The probe,radiolabeled with either[68Ga]Ga for diagnostic applications or[177Lu]Lu for therapeutic use,was synthesized with exceptional purity,stability,and specific activity.Extensive testing involving 12 different tumor cell lines revealed remarkable specificity towards B16 melanoma cells,showcasing outstanding tumor localization and target-to-non-target ratio.Mechanistic investigations employing polyamines,non-labeled precursor,and polyamine transport system(PTS)inhibitor,consistently affirmed the probe?s targetability through recognition of the PTS.Notably,while previous reports indicated PTS upregulation in various tumor types for targeted therapy,this study observed no positive signals,highlighting a concentration-dependent discrepancy between targeting for therapy and diagnosis.Furthermore,when labeled with[177Lu],the probe demonstrated its therapeutic potential by effectively controlling tumor growth and extending mouse survival.Investigations into biodistribution,excretion,and biosafety in healthy humans laid a robust foundation for clinical translation.This study introduces a versatile SPM-based nuclear probe with applications in precise tumor theranostics,offering promising prospects for clinical implementation.
