Publications by authors named "Alok Dhawan"

Article Synopsis
  • - The comet assay is a flexible method used to identify DNA damage in individual eukaryotic cells, applicable to various species from yeast to humans, detecting issues like DNA strand breaks and other forms of damage.
  • - Modifications to the protocol are necessary based on the specimen to minimize additional DNA damage during sample processing and to enhance the detection of damage differences.
  • - The method has been validated for various applications in research and has gained recognition as an in vivo genotoxicity test by the OECD, with guidelines provided for its use across different cell types and DNA damage assessments.
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Introduction: The COVID-19 pandemic resulted in substantial morbidity and mortality across the world. The prognosis was found to be poor in patients with co-morbidities such as diabetes, hypertension, interstitial lung disease, etc. Although biochemical studies were done in patient samples, no study has been reported from the Indian subcontinent about ultrastructural changes in the vital organs of COVID-19 patients.

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Genetic toxicology testing is a weight-of-evidence approach to identify and characterize chemical substances that can cause genetic modifications in somatic and/or germ cells. Prediction of genetic toxicology using computational tools is gaining more attention and preferred by regulatory authorities as an alternate safety assessment for in vivo or in vitro approaches. Due to the cost and time associated with experimental genetic toxicity tests, it is essential to develop more robust in silico methods to predict chemical genetic toxicity.

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DNA damage through endogenous and environmental toxicants is a constant threat to both a human's ability to pass on intact genetic information to its offspring as well as in somatic cells for its own survival. To counter these threats posed by DNA damage, cells have evolved a series of highly choreographed mechanisms-collectively defined as the DNA-damage response (DDR)-to sense DNA lesions, signal their presence, and mediate their repair. Thus, regular DDR signaling cascades are vital to prevent the initiation and progression of many human diseases including cancer.

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Human biomonitoring studies aim to identify potential exposures to environmental, occupational, or lifestyle toxicants in human populations and are commonly used by public health decision makers to predict disease risk. The Comet assay measures changes in genomic stability and is one of the most reliable biomarkers to indicate early biological effects and therefore accepted by various governmental regulatory agencies. The appeal of the Comet assay lies in its relative simplicity, rapidity, sensitivity, and economic efficiency.

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Anthropogenic activities, indiscriminate and rapid industrialization as well as pursuance of a better life has led to an increase in the concentration of chemicals, like pesticides, automobile exhausts, and new chemical entities, in the environment, which have an adverse effect on all living organisms including humans. Sensitive and robust test systems are thus required for accurate hazard identification and risk assessment. The Comet assay has been used widely as a simple, rapid, and sensitive tool for assessment of DNA damage in single cell from both in vitro and in vivo sources as well as in humans.

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Little is known of the effects of nanoparticles in human systems, let alone in diseased individuals and nanotechnology has preceded nanotoxicology. Therefore, the effects of titanium dioxide (TiO2) nanoparticles in peripheral blood lymphocytes from patients with respiratory diseases [lung cancer, chronic obstructive pulmonary disease (COPD) and asthma] were compared with those in healthy Individuals, to determine differences in sensitivity to nanochemical insult. The Comet assay was performed according to recommended guidelines.

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Over the last decade, there has been growing interest in developing novel nanoparticles (NPs) for biomedical applications. A safe-by-design approach was used in this study to synthesize biocompatible iron oxide NPs. The size of the particles obtained was ~100 nm.

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Curcumin has a broad spectrum of pharmacological activities, one of them is anticancer activity that is mediated through multiple mechanisms. The major disadvantage associated with the use of curcumin is its low bioavailability due to its poor aqueous solubility. Nanoformulations of curcumin provide an effective solution for this problem.

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Amyloid beta (Aβ) deposits are implicated in the pathogenesis of debilitating neurodegenerative disorders such as Alzheimer's disease. In the present study, the interactions of carbon-based nanoparticles (NPs) such as fullerene and fullerenol having different surface chemistry with Aβ were investigated using molecular dynamics simulations and docking studies. A detailed analysis of docking results showed that in 68% of the Aβ conformations, fullerene and fullerenol showed interactions with the N-terminal region of the peptide.

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Overproduction of free radicals contributes to oxidative stress and inflammation leading to various disease conditions. Cerium oxide nanoparticles (nanoceria) have been shown to scavenge free radicals and have the potential for being used as a therapeutic agent in disease conditions. Therefore, in the present study, human monocytic leukemia cells (THP-1) were used as a model to evaluate the uptake and free radical scavenging activity of nanoceria.

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Engineered nanoparticles (ENPs) possess different physical and chemical properties compared to their bulk counterparts. These unique properties have found application in various products in the area of therapeutics, consumer goods, environmental remediation, optical and electronic fields. This has also increased the likelihood of their release into the environment thereby affecting human health and ecosystem.

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Zinc oxide (ZnO) nanoparticles (NPs) have potential applications in cosmetics, food packaging and biomedicine but concerns regarding their safety need to be addressed. In the present study, the immunotoxic potential of ZnO NPs was evaluated in different ages of BALB/c mice after sub-acute exposure. The cytokine release, immunophenotyping, distribution of ZnO NPs and ultrastructural changes were assessed.

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The extensive use of zinc oxide nanoparticles (ZnO NPs) in cosmetics, sunscreens and healthcare products increases their release in the aquatic environment. The present study explored the possible interaction of ZnO NPs with montmorillonite clay minerals in aqueous conditions. An addition of ZnO NPs on clay suspension significantly (p<0.

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The increasing applications of engineered nanomaterials (ENMs) in consumer products warrant a careful evaluation of their trophic transfer and consequent ecological impact. In the present study, a laboratory scale aquatic microbial food chain was established using bacteria (Escherichia coli (E. coli)) as a prey and ciliated protozoan (Paramecium caudatum) as a predator organism to determine the impact of cadmium telluride quantum dots (CdTe QDs).

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An exponential development in the use of silver nanoparticles (AgNPs) in consumer products has accelerated their release in aquatic environment. As the AgNPs enters into the aquatic systems, their fate may change due to interactions with abiotic (e.g.

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Nano titanium dioxide (nTiO2) is the most abundantly released engineered nanomaterial (ENM) in aquatic environments. Therefore, it is prudent to assess its fate and its effects on lower trophic-level organisms in the aquatic food chain. A predator-and-prey-based laboratory microcosm was established using Paramecium caudatum and Escherichia coli to evaluate the effects of nTiO2.

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Metal oxide nanoparticles (NPs), including zinc oxide (ZnO) NPs have shown success for use as vehicles for drug delivery and targeting gene delivery in many diseases like cancer. Current anticancer chemotherapeutics fail to effectively differentiate between cancerous and normal cells. There is an urgent need to develop novel drug delivery system that can better target cancer cells while sparing normal cells and tissues.

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Currently the major research highlights of bioengineering and medical technology are directed towards development of improved diagnostic techniques to screen complex diseases. Screening requirements are to identify the cause of illnesses, monitor improvement or progression of the state of diseases such as cancer, cardiovascular or neurodegenerative diseases. Nanotechnology enables the manipulation of materials at nanoscale and has shown potential to enhance sensitivity, selectivity and lower the cost of a diagnosis.

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The interactions between nanomaterials (NMs) and amyloid proteins are central to the nanotechnology-based diagnostics and therapy in neurodegenerative disorders such as Alzheimer's and Parkinson's. Graphene oxide (GO) and its derivatives have shown to modulate the aggregation pattern of disease causing amyloid beta (Aβ) peptide. However, the mechanism is still not well understood.

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The wide application of zinc oxide nanoparticles (ZnO NPs) in cosmetics, paints, biosensors, drug delivery, food packaging and as anticancerous agents has increased the risk of human exposure to these NPs. Earlier in vitro and in vivo studies have demonstrated a cytotoxic and genotoxic potential of ZnO NPs. However, there is paucity of data regarding their immunomodulatory effects.

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Currently the major research highlights of bioengineering and medical technology are directed towards development of improved diagnostic techniques to screen complex diseases. Screening requirements are for the identification of the cause of illnesses, monitoring the improvement or progression of the state of diseases such as cancer, cardiovascular or neurodegenerative diseases. Nanotechnology enables the manipulation of materials at nanoscale and has shown potential to enhance sensitivity, selectivity and lower the cost of a diagnosis.

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Chromium oxide (Cr2 O3 ) nanoparticles (NPs) are being increasingly used as a catalyst for aromatic compound manufacture, abrading agents and as pigments (e.g., Viridian).

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