scholarly journals On the Mechanism and Kinetics of Synthesizing Polymer Nanogels by Ionizing Radiation-Induced Intramolecular Crosslinking of Macromolecules

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1765
Author(s):  
Aiysha Ashfaq ◽  
Jung-Chul An ◽  
Piotr Ulański ◽  
Mohamad Al-Sheikhly
Keyword(s):  
Ionizing Radiation ◽  
Absorbed Dose ◽  
Kinetics And Mechanism ◽  
Background Information ◽  
Potential Applications ◽  
Radiation Induced ◽  
Mechanism And Kinetics ◽  
Kinetics Of ◽  
Crosslinking Agents

Nanogels—internally crosslinked macromolecules—have a growing palette of potential applications, including as drug, gene or radioisotope nanocarriers and as in vivo signaling molecules in modern diagnostics and therapy. This has triggered considerable interest in developing new methods for their synthesis. The procedure based on intramolecular crosslinking of polymer radicals generated by pulses of ionizing radiation has many advantages. The substrates needed are usually simple biocompatible polymers and water. This eliminates the use of monomers, chemical crosslinking agents, initiators, surfactants, etc., thus limiting potential problems with the biocompatibility of products. This review summarizes the basics of this method, providing background information on relevant aspects of polymer solution thermodynamics, radiolysis of aqueous solutions, generation and reactions of polymer radicals, and the non-trivial kinetics and mechanism of crosslinking, focusing on the main factors influencing the outcomes of the radiation synthesis of nanogels: molecular weight of the starting polymer, its concentration, irradiation mode, absorbed dose of ionizing radiation and temperature. The most important techniques used to perform the synthesis, to study the kinetics and mechanism of the involved reactions, and to assess the physicochemical properties of the formed nanogels are presented. Two select important cases, the synthesis of nanogels based on polyvinylpyrrolidone (PVP) and/or poly(acrylic acid) (PAA), are discussed in more detail. Examples of recent application studies on radiation-synthesized PVP and PAA nanogels in transporting drugs across the blood–brain barrier and as targeted radioisotope carriers in nanoradiotherapy are briefly described.

Effect of ionizing radiation on the kinetics of hydrogenation on the Ni-MgO mixed catalyst

1982 ◽  
Vol 47 (7) ◽  
pp. 1780-1786 ◽  
Author(s):  
Rostislav Kudláček ◽  
Jan Lokoč
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Liquid Phase ◽  
Ionizing Radiation ◽  
Oxide Catalyst ◽  
Absorbed Dose ◽  
Hydrogenation Rate ◽  
Solution Composition ◽  
Mixed Catalyst ◽  
Kinetics Of

The effect of gamma pre-irradiation of the mixed nickel-magnesium oxide catalyst on the kinetics of hydrogenation of maleic acid in the liquid phase has been studied. The changes of the hydrogenation rate are compared with the changes of the adsorbed amount of the acid and with the changes of the solution composition, activation energy, and absorbed dose of the ionizing radiation. From this comparison and from the interpretation of the experimental data it can be deduced that two types of centers can be distinguished on the surface of the catalyst under study, namely the sorption centres for the acid and hydrogen and the reaction centres.

Therapeutic ionizing radiation induced bone loss: a review of in vivo and in vitro findings

2018 ◽  
Vol 59 (6) ◽  
pp. 509-522 ◽  
Author(s):  
Jian Zhang ◽  
Xinyu Qiu ◽  
Kedi Xi ◽  
Wentao Hu ◽  
Hailong Pei ◽  
...  
Keyword(s):  
Bone Loss ◽  
Ionizing Radiation ◽  
Radiation Induced

scholarly journals DNA Damage in Blood Leukocytes of Prostate Cancer Patients Undergoing PET/CT Examinations with [68Ga]Ga-PSMA I&T

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 388 ◽  
Author(s):  
Sarah Schumann ◽  
Harry Scherthan ◽  
Torsten Frank ◽  
Constantin Lapa ◽  
Jessica Müller ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Ex Vivo ◽  
Absorbed Dose ◽  
Dna Double Strand Breaks ◽  
Blood Leukocytes ◽  
Blood Samples ◽  
Time Points ◽  
Pet Ct ◽  
Radiation Induced

The aim was to investigate the induction and repair of radiation-induced DNA double-strand breaks (DSBs) as a function of the absorbed dose to the blood of patients undergoing PET/CT examinations with [68Ga]Ga-PSMA. Blood samples were collected from 15 patients before and at four time points after [68Ga]Ga-PSMA administration, both before and after the PET/CT scan. Absorbed doses to the blood were calculated. In addition, blood samples with/without contrast agent from five volunteers were irradiated ex vivo by CT while measuring the absorbed dose. Leukocytes were isolated, fixed, and stained for co-localizing γ-H2AX+53BP1 DSB foci that were enumerated manually. In vivo, a significant increase in γ-H2AX+53BP1 foci compared to baseline was observed at all time points after administration, although the absorbed dose to the blood by 68Ga was below 4 mGy. Ex vivo, the increase in radiation-induced foci depended on the absorbed dose and the presence of contrast agent, which could have caused a dose enhancement. The CT-dose contribution for the patients was estimated at about 12 mGy using the ex vivo calibration. The additional number of DSB foci induced by CT, however, was comparable to the one induced by 68Ga. The significantly increased foci numbers after [68Ga]Ga-PSMA administration may suggest a possible low-dose hypersensitivity.

Radiation Biomarkers : Applications in Triage Management of Radiation Victims

2017 ◽  
Vol 2 (3) ◽  
pp. 270
Author(s):  
Saurabh Mishra ◽  
Raj Kumar
Keyword(s):  
Ionizing Radiation ◽  
Absorbed Dose ◽  
Physiological Status ◽  
Scenario Development ◽  
Potential Health ◽  
Biological Responses ◽  
Gene And Protein Expression ◽  
Genetic Perturbations ◽  
Biologic Response ◽  
Radiation Induced

Human exposure to ionizing radiation disrupts normal metabolic processes in cells and organs by inducing complex biological responses that interfere with gene and protein expression. Conventional dosimetry, monitoring of prodromal symptoms and peripheral lymphocyte counts are of limited value as organ- and tissue-specific biomarkers for personnel exposed to radiation, particularly, weeks or months after exposure. Analysis of metabolites generated in known stress-responsive pathways by molecular profiling helps to predict the physiological status of an individual in response to environmental or genetic perturbations. There is a need for research to rapidly determine an individual’s absorbed dose and its potential health effects after a potential radiological or nuclear event that could expose large portions of a population to ionizing radiation. Studies on biomarker identification after radiation exposure could contribute in biodosimetry, identifying individual dose absorbed, as well as biologic response, and administering immediate and proper medical care. In the recent scenario development of biomarker is major thrust area. In the present review paper articles related to gene biomarker, protein biomarker and metabolic biomarker are reviewed in order to sketch an overview on the recent advances related to developing an biomarker to assess the radiation induced toxicity.

Investigation of the Radiation-Induced Signal of Electron Paramagnetic Resonance of Eggshell after Irradiation with Electron Beams

ANRI ◽  
2021 ◽  
Vol 0 (2) ◽  
pp. 75-84
Author(s):  
Anastasia Chumanova ◽  
Ruslan Vazirov ◽  
Sergey Sokovnin ◽  
Ekaterina Agdantseva ◽  
Anton Tsmokalyuk
Keyword(s):  
Comparative Analysis ◽  
Absorbed Dose ◽  
Radiation Processing ◽  
Paramagnetic Resonance ◽  
Radiation Induced ◽  
Epr Signal ◽  
Induced Signal ◽  
Chicken Eggs ◽  
Kinetics Of ◽  
Over Time

Because of the development of radiation processing of food and agricultural products it requires new methods of control over the processing and turnover of products. A promising method for monitoring is EPR spectrometry. This research presents the results of a study of the radiation induced EPR signal in eggshells. The URT-0.5 (0.5 MeV) and UALR-10-10 S2 (10 MeV) accelerators were used for irradiation. It shows the kinetics of radicals over time. The dependences of the EPR signal intensity on the absorbed dose were obtained, and a comparative analysis of the irradiation of chicken eggs with different energies was performed. The kinetics of radicals over time and the dependence of the intensity of the EPR signal on the absorbed dose are shown. A comparative analysis of the irradiation of chicken eggs with different energies is carried out.

Lovastatin attenuates ionizing radiation-induced normal tissue damage in vivo

2009 ◽  
Vol 92 (3) ◽  
pp. 492-499 ◽  
Author(s):  
Christian Ostrau ◽  
Johannes Hülsenbeck ◽  
Melanie Herzog ◽  
Arno Schad ◽  
Michael Torzewski ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Tissue Damage ◽  
Normal Tissue ◽  
Normal Tissue Damage ◽  
Radiation Induced

scholarly journals The kinetics of γ-H2AX during radiotherapy of head and neck cancer potentially allow for prediction of severe mucositis

2020 ◽  
Vol 54 (1) ◽  
pp. 96-102
Author(s):  
Joanna Kazmierska ◽  
Wojciech Barczak ◽  
Tomasz Winiecki ◽  
Łukasz Łuczewski ◽  
Magdalena Marciniak ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Head And Neck ◽  
Neck Cancer ◽  
Peripheral Blood Lymphocytes ◽  
Significant Difference ◽  
Radiation Induced ◽  
The Difference ◽  
Kinetics Of ◽  
Severe Mucositis

AbstractBackgroundThe aim of the study was to evaluate the changes in γ-H2AX expression in peripheral blood lymphocytes (PBL) according to severity of radiation-induced mucositis.Patients and methodFifty patients with head and neck cancer treated with radiotherapy (RT) or chemoradiation were included in the study. Blood samples were collected before treatment to measure baseline γ-H2AX levels. Second sample was taken 45 minutes after the first RT fraction and then once a week, 45 min after irradiation. In patients treated with chemoradiation the blood sample was taken the day after chemotherapy. Mucositis was evaluated once a week and reported according to CTCAE v4 and RTOG/EORTC scales. PBL were analyzed with flow cytometry and level of H2AX phosphorylation at every time point was evaluated.ResultsIn 35 patients mild to moderate (grade 1–2) mucositis was observed and 15 patients developed severe (grade 3) mucositis. No cases of grade 4 mucositis were observed. The difference in baseline levels of γ-H2AX between groups with mild and severe mucositis was statistically insignificant (p = 0.25). The statistically significant difference in γ-H2AX level was observed in week 7 of treatment (p = 0.01). No significant differences in γ-H2AX level were found neither between group treated with concomitant chemoradiation or RT alone neither between groups with and without common comorbidities. In the analysis of the kinetics of γ-H2AX during treatment, a statistically significant difference (p = 0.0088) between groups with mild and severe mucositis was observed. After fourth week of treatment levels of γ-H2AX decreased significantly in the group with severe mucositis and increased in patients with mild side effects. The observed difference was not caused by the decrease in peripheral lymphocyte count, which was similar in both groups.ConclusionsPresented results indicate that severity of radiation-induced mucositis does not correlate directly with γ-H2AX levels measured in vivo in PBL. Prediction of mucositis grade based on γ-H2AX level is not yet possible, either before treatment or early during treatment, but preliminary results, indicating significant differences in γ-H2AX kinetics between groups, encourage further studies.

Sign in / Sign up

Export Citation Format

Share Document