Current radiopharmaceuticals最新文献

Targeted Alpha Therapy (TAT) is considered an evolving therapeutic option for cancer cells, in which a carrier molecule labeling with an α-emitter radionuclide make the bond with a specific functional or molecular target. α-particles with high Linear Energy Transfer (LET) own an increased Relative Biological Effectiveness (RBE) over common β-emitting radionuclides. Normal tissue toxicity due to non-specific uptake of mother and daughter α-emitter radionuclides seems to be the main conflict in clinical applications. The present survey reviews the available preclinical and clinical studies investigating healthy tissue toxicity of the applicable α -emitters and particular strategies proposed for optimizing targeted alpha therapy success in cancer patients.

Background: During a radiological or nuclear disaster, exposure to a high dose of ionizing radiation usually results in cardiovascular diseases such as heart failure, attack, and ischemia.

Objective: The purpose of this study was to examine the mitigation effects of Spirulina in comparison to Metformin's.

Methods: 25 male Wistar rats were randomly assigned to five groups (5 rats in each): for the control group, rats did not receive any intervention. In group 2, spirulina was administered orally to rats. In group 3, rats were irradiated to the chest region with 15 Gray(Gy) x-radiation. In groups 4 and 5, rats were irradiated in the same way as group 3. Forty-eight hours after irradiation, treatment with Spirulina and Metformin began. All rats were sacrificed after ten weeks, and their heart tissues were removed for histopathological and biochemical assays.

Results: Results showed an elevation in Malondialdehyde (MDA) and decreasing superoxide dismutase (SOD) activity. Moreover, pathological changes of radiation were irregularities in the arrangement of myofibrils, proliferation, migration of mononuclear cells, vacuolation of the cytoplasm, and congestion. Administration of spirulina enhanced the SOD activity while did not affect MDA level and pathological change in heart tissue. Despite spirulina, metformin had a considerable effect on pathological lesions and decreased the level of MDA.

Conclusion: Reactive oxygen species (ROS) may be involved in the late effects of radiationinduced heart injury, and scavenging these particles may contribute to reduced radiation side effects. Based on these results, Spirulina had no effect on radiation-induced cardiac damage, while metformin did. Higher Spirulina doses given over a longer period of time will likely have a greater heart-mitigate effect.

Background: Glioblastoma is the most common primary malignant tumor of the central nervous system. The patient's median survival rate is 13.5 months, so it is necessary to explore new therapeutic approaches.

Objective: Extremely low-frequency electromagnetic field (EMF) has been explored as a noninvasive cancer treatment. This study applied the EMF with previous conventional chemoradiotherapy for glioblastoma.

Methods: In this study, we evaluated the cytotoxic effects of EMF (50 Hz, 100 G), temozolomide (TMZ), and radiation (Rad) on gene expression of T98 glioma cell lines in monolayer and spheroid cell cultures.

Results: Treatment with Rad and EMF significantly increased apoptosis-related gene expression compared to the control group in monolayers and spheroids (p<0.001). The expression of apoptotic-related genes in monolayers was higher than the similar spheroid groups (p<0.001). We found that treatment with TMZ and EMF could increase the gene expression of the autophagy cascade markers compared to the control group (p<0.001). Autophagy-related gene expression in spheroids was higher than in the similar monolayer group (p<0.001). We demonstrated that coadministration of EMF, TMZ, and Rad significantly reduced cell cycle and drug resistance gene expression in monolayers and spheroids (p<0.001) compared to the control group.

Conclusion: The combinational use of TMZ, Rad and, EMF showed the highest antitumor activity by inducing apoptosis and autophagy signaling pathways and inhibiting cell cycle and drug resistance gene expression. Furthermore, EMF increased TMZ or radiation efficiency.

This minireview describes the global situation of ongoing research and development and the clinical application of alpha emitter labeled immunoconjugates with various alpha emitters with an overview of the future trends. The potentially helpful alpha emitter radioisotopes for medical applications, chelators, and immunomolecules of interest for future alpha radioimmunotherapy are discussed. Challenges and some suggested future works on chelators are also presented.

Background: Radiopharmaceuticals labeled with [⁶⁸Ga] from positron emission tomography (PET) radionuclides are utilized in nuclear medicine for non-invasive in vivo molecular imaging. Buffer solutions for radiolabeling play an important role as choosing the right buffer for the reaction helps to obtain high yield radiopharmaceuticals. Zwitterionic organic buffer 4-(2- hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), sodium acetate (CH₃COONa), sodium bicarbonate (NaHCO₃) buffers are widely used for labeling of peptides with [⁶⁸Ga]Cl₃. They can be used for peptide labelings with the acidic [⁶⁸Ga]Cl₃ precursor of triethanolammonium (TEA) buffer. The cost and toxicity of TAE buffer are relatively low.

Method: For [⁶⁸Ga]GaPSMA-HBED-CC and [⁶⁸Ga]GaDOTA-TATE labeling, the effectiveness of TEA buffer without chemical impurities in radiolabeling reactions and QC parameters in successful labeling was investigated.

Results: The method used to label [⁶⁸Ga]Cl₃ with PSMA-HBED-CC peptide in the presence of TEA buffer was successful when applied at room temperature. High purity radiosynthesis suitable for clinical use was performed to obtain DOTA-TATE peptide with the addition of 363K temperature and radical scavenger. Quality control tests with R-HPLC have shown that this method is suitable for clinical use.

Conclusion: We present an alternative procedure for labeling PSMA-HBED-CC and DOTATATE peptides with [⁶⁸GaCl₃] to obtain high radioactive doses of final radiopharmaceutical products used in nuclear medicine clinical applications. We have provided a quality-controlled final product that can be used in clinical diagnostic procedures. With the use of an alternative buffer, these methods could be adapted to semi-automatic or automated modules routinely used in nuclear medicine laboratories to label [⁶⁸Ga]-based radiopharmaceuticals.

Introduction: With its suitable nuclear decay characteristics and large-scale production feasibility with adequate specific activity, ¹⁷⁷Lu is regarded as an excellent radionuclide for developing bone pain palliation agent. Ethylenediamine-tetramethylene phosphonic acid (EDTMP) is a preferred carrier molecule for radiolanthanides, such as ¹⁷⁷Lu. The present paper describes the synthesis of EDTMP and the development of a ready-to-use kit for the preparation of ¹⁷⁷Lu-EDTMP and its quality control in accordance with the quality and safety criteria required for medicinal use.

Material and methods: EDTMP was synthesized by a modified Mannich-type reaction, and the structure was characterized using NMR and IR spectroscopy. Optimization of radiolabeling conditions was done with two different salt forms of EDTMP. The labeling yield was checked by paper chromatography with radiation detection. Kit was developed as a lyophilized mixture of EDTMP and sodium bicarbonate in a maximum volume of 5 mL. Labeling efficiency, radionuclidic purity, radiochemical purity, sterility, and pyrogenicity analysis were performed as the quality control of the labeled kit.

Results: The analytical data for the structure determination and purity of the synthesized ligand were in agreement with authentic commercial samples used in radiopharmacy.¹⁷⁷Lu-EDTMP complex was prepared using synthesized EDTMP ligand under optimized labeling conditions with high labelling yield (>99%). The radiolabeling yields of the EDTMP kit at room temperature after 30 min and 48 hours were 99.46% and 99.00%.

Conclusion: The developed EDTMP kit enables an instant one-step preparation of the radiopharmaceutical of high radiochemical purity (>99%) and has a sufficiently long shelf life. This enables the routine production of the ¹⁷⁷Lu-EDTMP in nuclear medicine clinics without requiring experienced staff.

Introduction: Hypoxia imaging agents can selectively remain in hypoxic tissue, which can directly reflect the location and degree of hypoxia.

Methods: Synthesized a novel tumor hypoxia imaging probe [^99mTc]Tc(CO)₃-CPA-2-NIM and evaluated its biological behavior with the purpose to assess its possibility of becoming a qualified tumor hypoxia imaging agent.

Results: Radiochemcial purity of [^99mTc]Tc(CO)₃-CPA-2-NIM was greater than 95% after HPLC purification. Lipophilicity coefficient of this complex was -1.74 ± 0.10 (n = 5, number of experiments), indicating it was a hydrophilic complex. In vitro cell experiments demonstrated that this complex has selectivity for hypoxia at oxygen concentrations < 10 ppm (parts per million). Biodistribution experiment in S180 tumor bearing mice showed that tumor uptake reached its highest at 2 h post-injection with mice tumor-to-muscle ratio.

Conclusions: Complex [^99mTc]Tc(CO)₃-CPA-2-NIM has the possibility of becoming a tumor hypoxia imaging agent.

Background: Bone metastatic involvement represents a leading cause of death in patients with advanced breast cancer (BC). At present, it is not clear whether the bone metastatic load might impact Overall Survival (OS) in patients with bone metastatic BC at diagnosis. For this purpose, we used the Bone Scan Index (BSI), which is a reproducible and quantitative expression of tumor load observed at bone scintigraphy.

Objective: The aim of this study was to associate BSI with OS in bone metastatic BC patients.

Methods: In this retrospective study, we enrolled BC patients with bone metastases at the scintigraphic bone scan performed for staging purposes. The BSI was calculated through the DASciS software, and statistical analysis was carried out. Other clinical variables relevant to OS analysis were taken into account.

Results: Of a total of 94 patients, 32% died. In most cases, the histotype was ductal infiltrating carcinoma. The median OS from diagnosis was 72 months (CI 95%: 62-NA). The univariate analysis with COX regression showed that only hormone therapy significantly correlates with OS (HR 0.417, CI 95%: 0.174-0.997, p < 0.049). As concerning BSI, the statistical analysis showed that it does not predict OS in BC patients (HR 0.960, 95% CI: 0.416-2.216, p < 0.924).

Conclusion: Although the BSI significantly predicts OS in prostate cancer and in other tumors, we observed that the metastatic load of bone disease has not a key role in prognostic stratification in our population.

Background: Some compounds have been investigated to mitigate the effect of radiation on the lung, such as pneumonitis and fibrosis.

Objective: This study aimed to examine the mitigation efficiency of Spirulina compared to the effect of Metformin.

Methods: 25 male Wistar rats were allotted in five groups: control, Spirulina, Radiation, Radiation plus Spirulina, and Radiation plus Metformin. Rat chest regions were irradiated by 15 Gray (Gy) xradiation using aLINAC. Forty-eight hours after irradiation, treatment with Spirulina and Metformin began. Eighty days after irradiation, all rats were sacrificed, and their lung tissues were removed for histopathological, and biochemical assays.

Results: The results demonstrated that irradiation increased MDA (Malondialdehyde) levels while suppressing the SOD (superoxide dismutase) and GPx(glutathione peroxidase) activity in the irradiated group. MDA levels in lung tissues were reduced with Metformin but not with Spirulina. Both Metformin and Spirulina increased the SOD and GPx activity in lung tissue. Moreover, histopathological evaluations showed extensive changes in the lung tissue including infiltration of lymph cells around the bronchioles and blood vessels, thickening of the alveolar wall, and the disruption of the alveolar structure, as well as accumulation of collagen fibers. Administration of Spirulina and Metformin significantly reduced pathological changes in lung tissue, although the effect of Metformin was greater than that of Spirulina.

Conclusion: Spirulina could mitigate radiation-induced lung injury moderately, although Metformin is more effective than Spirulina as a mitigator agent.

Nanotechnology has changed the world, with a great impact on industry and medicine. In this commentary, we discuss the importance of radiolabeled nanomaterials for the construction of theranostic, imaging and therapeutic agents in order to pave the future of medicine.