Sudha Rana

Radiation-induced biomarkers for the detection and assessment of absorbed radiation doses

Radiation incident involving living organisms is an uncommon but a very serious situation. The first step in medical management including triage is high-throughput assessment of the radiation dose received. Radiation exposure levels can be assessed from viability of cells, cellular organelles such as chromosome and different intermediate metabolites. Oxidative damages by ionizing radiation result in carcinogenesis, lowering of the immune response and, ultimately, damage to the hematopoietic system, gastrointestinal system and central nervous system. Biodosimetry is based on the measurement of the radiation-induced changes, which can correlate them with the absorbed dose. Radiation biomarkers such as chromosome aberration are most widely used. Serum enzymes such as serum amylase and diamine oxidase are the most promising biodosimeters. The level of gene expression and protein are also good biomarkers of radiation.

Electron paramagnetic resonance spectroscopy in radiation research: Current status and perspectives

Exposure to radiation leads to a number of health-related malfunctions. Ionizing radiation is more harmful than non-ionizing radiation, as it causes both direct and indirect effects. Irradiation with ionizing radiation results in free radical-induced oxidative stress. Free radical-mediated oxidative stress has been implicated in a plethora of diseased states, including cancer, arthritis, aging, Parkinsons disease, and so on. Electron Paramagnetic Resonance (EPR) spectroscopy has various applications to measure free radicals, in radiation research. Free radicals disintegrate immediately in aqueous environment. Free radicals can be detected indirectly by the EPR spin trapping technique in which these forms stabilize the radical adduct and produce characteristic EPR spectra for specific radicals. Ionizing radiation-induced free radicals in calcified tissues, for example, teeth, bone, and fingernail, can be detected directly by EPR spectroscopy, due to their extended stability. Various applications of EPR in radiation research studies are discussed in this review.

p-Tertbutylcalix[4]arene nanoemulsion: preparation, characterization and comparative evaluation of its decontamination efficacy against Technetium-99m, Iodine-131 and Thallium-201.

This study aimed to develop p-tertbutylcalix[4]arene o/w nanoemulsion for decontamination of radioisotopes from skin. Formulation was characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), multi-photon confocal microscopy techniques and in vitro dissolution studies. In vivo evaluation of nano-emulsion was done using nuclear medicine technique. Stability studies and dermal toxicity studies were also carried out. Comparative decontamination efficacy (DE) studies were performed on synthetic human tissue equivalent material and Sprague Dawley rat against three commonly used medical radioisotopes, i.e., Technetium-99m ((99m)Tc), Iodine-131 ((131)I) and Thallium-201 ((201)Tl). Decontamination was performed using cotton swabs soaked in nanoemulsion at different time intervals of contaminants exposure. Whole body imaging and static counts were recorded using gamma camera before and after each decontamination attempt data was analyzed using one way analysis of variance (ANOVA) and found to be statistically significant (p<0.05). DE of the nanoemulsion loaded with p-tertbutylcalix[4]arene was observed to be 88±5%, 90±3% and 89±3% for (99m)Tc, (131)I and (201)Tl respectively. Dermal toxicity studies revealed no significant differences between treated and control animals. Skin histopathology slides with and without API (Active pharmaceutical ingredients) also found to be comparable. p-Tertbutylcalix[4]arene loaded nanoemulsion shows great promise for skin decontamination against broad ranges of radiological contaminants besides being stable and safe.

Para-tert-butylcalix[4]arene as promising complexing agent for removal of the strontium from the aqueous medium

Strontium-90 is one of radioactive nuclear fallout products, can cause serious health effects. Efficient techniques are needed to remove radioactive strontium from contaminated persons. In this study complexation properties of the p-tert-butylcalix[4]arene has been evaluated against cold strontium nitrate. Ultra violet-visible (UV-vis) and fluorescence spectrophotometric techniques were used for the qualitative analytical screening and the inductively coupled plasma-atomic emission spectrometry (ICP-AES) technique used for the quantitative complexation of p-tert-butylcalix[4]arene with strontium nitrate. UV-vis, fluorescence spectroscopy and ICP-AES studies confirmed the complexation of p-tert-butylcalix[4]arene and strontium. Extraction study of strontium from picric acid by trans-chelation method proves that p-tert-butylcalix[4]arene is nearly 87% ± 3% effective. Complexation can be attributed to the cation-lone pair interaction and the bonding between the Sr 2+ and the hydroxyl group of the p-tert-butylcalix[4]arene implying its promise as a complexing agent for the removal of strontium.

Radio-decontamination efficacy and safety studies on optimized decontamination lotion formulation

Objective of the present study was to optimize decontamination lotion and to evaluate its relative decontamination efficacy using three radio-isotopes (Technetium-99m, Iodine-131 and Thallium-201) as contaminants with varying length of contaminant exposure (0-1h). Experiments were performed on Sprague Dawley rats intact skin and human tissue equivalent models. Rats hair was removed by using depilator after trimming with scissors. Relative decontamination efficacy of the optimized lotion was investigated and compared with water as control. Static counts were recorded before and after decontamination using single photon emission computed tomography (SPECT). Measured decontamination efficacy (DE) values were analyzed using one way ANOVA and Students t-test (p value<0.05) and were found statistically significant. Decontamination efficacy of the lotion was observed to be 90 ± 5%, 80 ± 2% and 85 ± 2%, for the (131)I, (201)Tl and (99m)Tc radio-contaminants respectively on skin. Reduced contaminant removal was recorded for the skin which was cleaned by depilator (50-60%). Skin decontamination was found more efficacious for rat skin decontamination than the human tissue equivalent model. Decontamination efficacy of the lotion against (99m)Tc was recorded 70 ± 15% at 0-1h on the tissue equivalent model. In vitro chelation efficacy of the lotion was also established by using the instant thin layer chromatography-slica gel (ITLC-SG) and >95% of (99m)Tc was recorded. Neither erythema nor edema was scored in the primary skin irritancy test visually observed for two weeks.

Skin decontamination cream for radiological contaminants: Formulation development and evaluation.

Background: Increased use of the radioactive materials in the field of research, medical, nuclear power plant, and industry has increased the risk of accidental exposure. Intentional use of the radioisotopes by terrorist organizations could cause exposure/contamination of a number of the population. In view of the accidental contamination, there is a need to develop self-usable decontamination formulations that could be used immediately after contamination is suspected. Materials and Methods: Present work was planned to optimize and develop self-usable radiation decontamination cream formulation. Various pharmaceutical parameters were characterized. 99mTc-sodium pertechnetate was used as radiocontaminant. Static counts were recorded before and after decontamination using single photon emission computed tomography. Results: Decontamination efficacy of the cream was found to be 42% ± 3% at 0-0.5 h after the exposure. Primary skin irritancy test was satisfactory as no erythema or edema was observed visually after 2 weeks of the formulation application. Conclusion: The decontamination studies proved the potential of EDTA to remove the radiological contaminants effectively.

Chemical, biological, radiological, and nuclear threats-Decontamination technologies and recent patents: A review

With the increase in the intensity of threats perception and possibility of mass casualties in case of a chemical, biological, radiological, and nuclear (CBRN) emergency, there is a need to develop novel and effective systems for decontamination. The natural calamity in Japan leading to world’s most critical nuclear emergency exposed lack of decontamination formulation and technologies globally. There is a need to develop novel and effective systems for decontamination as the current technologies are expensive and cannot be used by victim themselves. Decontamination formulations that can be used by victims themselves are need of time. The review gives a brief introduction about the various CBRN agents and a concise discussion about the decontamination technologies available globally. The article also provides a review of the existing patents on the methods, equipment/devices used in CBRN decontamination.

In Vivo Imaging Techniques of the Nanocarriers Used for Targeted Drug Delivery

In vivo imaging of nanocarrier mediated targeted drug delivery is a relatively new methodology gaining fast acceptance in biomedical research and clinical practice. Imaging modalities frequently utilized for in vivo research are mostly adaptations from familiar, clinical imaging instrumentation such as X-ray Computed Tomography (CT), gamma scintigraphy, Magnetic Resonance Imaging (MRI), Optical imaging, Positron Emission Tomography (PET), and Fluorescence imaging. However, applications of newer technologies such as Optical imaging originated with laboratory animal applications are not ruled out for long term translational applications to derive the requisite information. Each of the technologies described subsequently allow for noninvasive, non-traumatic imaging over a time course. Acquisition times as well as sensitivity, specificity, resolution, ease of use, and cost of these methodologies vary. Different imaging techniques are used to assess different parameters such as anatomical, physiological, pharmacological, and molecular information. In certain cases, multi-modality approaches may be necessary. A number of studies have been reported for imaging the nanocarriers used for targeted drug delivery using these techniques for their preclinical evaluation.