China
Africa
Explore chapters and articles related to this topic
The History of Nuclear Medicine
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
In springtime 1920, de Hevesy went to the Niels Bohr Institute in Copenhagen and spent six years in an extensive research programme, discovering hafnium (Copenhagen in Latin). He first applied a radioactive isotope, thorium-B (212Pb) in a study pertaining to the solubility of lead salts. George de Hevesy realized that the method could be used to study biological processes. At that time, experiments in vivo were difficult because only toxic substances were available, and he limited his first experiments for studying the uptake and distribution in a flowering plant, that is, the fava bean (Vicia faba). However, in 1924, together with J.A. Christiansen and Sven Lomholt, he presented the first results from animal studies; 210Pb and 210Bi were used. Additionally, this excellent scientist presented further discoveries when more human-friendly radio isotopes became available [1, 12, 13].
Inhalation Toxicity of Metal Particles and Vapors
Published in Jacob Loke, Pathophysiology and Treatment of Inhalation Injuries, 2020
Hafnium is not essential to man or animals, and it is not reported to be involved in any biochemical systems; there are very few published reports about Hf metabolism. Toxicology studies on Hf are also rare. Lack of toxicology data on Hf leads to speculation on Hf toxicity. Owing to its similarity with Zr and Ti in chemical properties, one may assume that its metabolism in living tissues is similar but less traumatic because of the increased stability of the oxides formed. The higher electropositivity of Hf may render the chelation complexes of Hf with OH-containing ligands very stable, and thereby confer somewhat higher toxicity to Hf than Ti or Zr.
Nanotechnology-Mediated Radiation Therapy
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
Hafnium oxide (hafnia, HfO2), due to their photo-luminescence, high atomic number, electron density, and chemical stability, potentiates its application as a radiosensitizing agent for radiation therapy, while exhibiting chemical inertness in cellular and subcellular systems [125]. Nanobiotix (http://www.nanobiotix.com/en/), a biotechnology company specializing in nanomedicine, developed the functionalized crystalline HfO2 NPs, NBTXR3 with size of 50 nm. The surface negative charge of NBTXR3 allows for binding and facilitating rapid cellular internalization in the cancer cells. The aqueous suspension of NBTXR3 makes it feasible to administer both locally and intratumorally [151]. High-energy photon exposure of NBTXR3 resulted in significant radiation dose enhancement demonstrated by Monte Carlo simulation with tolerable toxicity levels [152]. Biological effects of NBTXR3 was studied in different cancer cell lines displaying differential uptake of the NPs forming clusters in the cytoplasm, where the DEF was increased depending on the concentration of NBTXR3 and radiation dose [153]. HfO2 NPs in combination with radiation therapy was also studied in mice models to observe the anti-tumor immune response contrary to radiation therapy alone treatment revealing increased CD8+ cells in HfO2 NPs plus radiation therapy treated and untreated tumors with no marked increase in radiation therapy alone treated tumors [154]. A clinical trial on the safety and efficacy of NBTXR3 activated by radiotherapy versus radiation therapy alone as a pre-operative treatment in soft tissue sarcoma patients is registered with ClinicalTrials.gov (NCT02379845) [155].
Saliva diagnostics: emerging techniques and biomarkers for salivaomics in cancer detection
Published in Expert Review of Molecular Diagnostics, 2022
Jieren Liu, Dongna Huang, Yuanzhe Cai, Zhihua Cao, Zhiyu Liu, Shuo Zhang, Lin Zhao, Xin Wang, Yuchuan Wang, Feijuan Huang, Zhengzhi Wu
A novel optical microfluidic biosensor with polythiophene (Figure 6A) was developed by Tao et al. It showed good analytical performance for salivary IL-8, IL-1β and MMP-8 with low detection limit, high detection specificity and reproducibility [159]. For the detection of oral cancer biomarker (CYFRA-21-1) in human saliva, Kumar et al. synthesized hafnium oxide nanoparticles by a low-temperature hydrothermal method, developed a non-invasive, label-free immunosensor (Figure 6B) based on nanostructured hafnium oxide (hafnia) and validated the sensor with high sensitivity [160]. Elif et al. fabricated a sensitive and label-free impedance immunosensor (Figure 6C) based on a 6-phosphonohexanoic acid (PHA) modified ITO electrode for the detection of IL-8 in human serum and saliva, achieving a low detection limit of 6 fg/mL [161]. Rong-NaMa and colleagues designed a unique and versatile ratiometric electrochemical DNA biosensor (Figure 6D) for the detection of overexpressed DNA species associated with oral cancer in saliva, achieving a detection limit of 12.8 fM over a linear range of 0.02 pM to 2 nM [162]. In Table 4 below we summarized the latest biosensor devices for detecting specific biomarkers associated with cancers.
Lutetium Lu 177 vipivotide tetraxetan for metastatic castration-resistant prostate cancer
Published in Expert Review of Anticancer Therapy, 2022
Hina Shah, Praful Ravi, Guru Sonpavde, Heather Jacene
177Lu is manufactured using a nuclear reactor and has a physical half-life of 6.6 days. It decays to the stable isotope Hafnium-177 via both beta-minus and gamma emissions. The beta-minus energies of 177Lu are 498 keV (79.3%), 176 keV (12.2%), and 380 keV (9.1%) [35]. The therapeutic activity of 177Lu is derived from these beta-minus (β−) emissions. The mean tissue penetration of 177Lu beta-minus emissions is 0.67 mm with a maximum tissue penetration of about 2 mm [11,35], thus making it effective against small-sized tumors. Although it has a short range, bystander and crossfire effects are still seen. 177Lu also emits low-energy gamma radiations with energies of 208 keV (11%) and 113 keV (6.4%) [35]. These gamma radiations allow for single-photon planar or tomography imaging after treatment with 177Lu-vipivotide tetraxetan.
Targeting of radio-enhancing drugs
Published in International Journal of Radiation Biology, 2022
In a recent review of the literature concerned with the clinical application of nanoparticles indicated that the two main NPs to be used in clinical trials were hafnium oxide and gadolinium. A total of 229 patients had been reported in trials in which hafnium oxide NP was used. These included three phase 1/2 trials on sarcoma, head and neck squamous cell carcinoma or liver cancer and one phase 2/3 trial. At the time of publication of the report, six phase 1/2 clinical trials to evaluate the combination of gadolinium-based NP and RT for the treatment of brain metastases and cervical cancer were ongoing.