Browsing by Author "Reshma, VG"

Now showing 1 - 7 of 7
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    Assessment of Immunotoxicity and Oxidative Stress Induced by Zinc Selenium/Zinc Sulphide Quantum Dots
    (Frontiers in Nanotechnology, 2021-02) Reshma, VG; Mohanan, PV
    Although ZnSe/ZnS quantum dots (QDs) have emerged as apparently less hazardous substitute to cadmium-based QDs, their toxicity has not been fully understood. Huge levels of ROS production and associated difficulties comprise the underlying reason for nanomaterial toxicity in cells. This will cause both immunotoxicity and genotoxicity. In the current work, Zinc Selenium/Zinc Sulphide (ZnSe/ZnS) QDs was synthesized, characterized and analyzed for its role in oxidative stress induction in two cell lines (HepG2 and HEK) and Swiss Albino mice. ROS production and influence of catalase activity in ROS production measured by DCFHDA assay in both HepG2 and HEK cells after exposure to ZnSe/ZnS QDs. Assessment of nitrile radical formation carried out by griess reagent. Level of GSH is assessed as a marker for oxidative stress induced by QDs. Cell death induced after exposure to ZnSe/ZnS QDs investigated by Calcein AM-PI live dead assay. Apoptotic DNA ladder assay carried out for studying the potential of ZnSe/ZnS QDs to induce DNA fragmentation. In vivo bio-nano interaction was studied by exposing Swiss Albino mice to ZnSe/ZnS QDs via i.v. and i.p. injection. Antioxidant assays were carried out in brain and liver homogenates to study the oxidative stress. LPO, GSH, GPx, GR and SOD are considered as biomarkers for the stress analysis. Blood brain barrier (BBB) integrity also studied. Spleenocytes proliferation assay was carried out to study the immunotoxicity response. ZnSe/ZnS QDs do not induce visible oxidative stress upto a concentration of 50 μg/ml. Cell death occurs at higher concentration (100 μg/ml) caused by ROS production. Overall study apparently provide attentive information that ZnSe/ZnS QDs is not capable of eliciting any serious damages to liver and brain tissues which in turn substantiates its applicability in biomedical applications.
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    Engineered Nanoparticles with Antimicrobial Property
    (Current Drug Metabolism, 2018-03) Reshma, VG; Syama, S; Sruthi, S; Reshma, SC; Remya, NS; Mohanan, PV
    Abstract: Background: The urge for the development and manufacture of new and effective antimicrobial agents is particularly demanding especially in the present scenario of emerging multiple drug resistant microorganisms. A promising initiative would be to converge nanotechnology to develop novel strategies for antimicrobial treatment. These distinct nano scale properties confer impressive antimicrobial capabilities to nanomaterials that could be exploited. Nanotechnology particularly modulates the physicochemical properties of organic and inorganic nanoparticles, rendering them suitable for various applications related to antimicrobial therapy compared to their bulk counterparts. However, a major issue associated with such usage of nanomaterials is the safety concern on heath care system. Hence, a thorough put knowledge on biocompatible nanostructures intended for antimicrobial therapy is needed. Methods: A systematic review of the existing scientific literature is being attempted here which includes the properties and applications of a few nano structured materials for antimicrobial therapy and also the mechanism of action of nanomaterials as antimicrobial agents. Silver (Ag), Graphene, Quantum dots (QDs), Zinc oxide (ZnO) and chitosan nanoparticles are taken as representatives of metals, semiconductors, metal oxides and organic nanoparticles that have found several applications in antimicrobial therapy are reviewed in detail. Results and Conclusion: An ideal anti microbial should selectively kill or inhibit the growth of microbes but cause little or no adverse effect to the host. Each of the engineered nanomaterials reviewed here has its own advantages and disadvantages. Nanomaterials in general directly disrupt the microbial cell membrane, interact with DNA and proteins or they could indirectly initiate the production of reactive oxygen species (ROS) that damage microbial cell components and viruses. Some like silver nanoparticles have broad spectrum antibacterial activity while others like cadmium containing QDs shows both antibacterial as well as antiprotozoal activity. Nano material formulations can be used directly or as surface coatings or as effective carriers for delivering antibiotics. Polycationic nature of Chitosan NPs helps in conjugation and stabilization of metallic nanoparticles which will enhance their effective usage in antimicrobial therapy.
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    In vitro and In vivo toxicity analysis of zinc selenium/zinc sulfide (ZnSe/ ZnS) quantum dots
    (Food and Chemical Toxicology, 2020-11) Reshma, VG; Sabareeswaran, A; Rajeev, KS; Mohanan, PV
    Despite the versatility of quantum dots (QDs) in optoelectronics and biomedical field, their toxicity risks remain a considerable hindrance for clinical applications. Cytotoxicity of Cadmium containing QDs is well documented and reveals that they are toxic to cells. Reports suggest that the presence of toxic elements at the QD core (e.g., cadmium, selenium) is responsible for its toxicity in in vivo and in vitro levels. Hence, here the toxicity of heavy metal free ZnSe/ZnS QDs on two scenarios were assessed, (i) HEK cells as in vitro system and (ii) Swiss Albino mice as in vivo model. Before toxicity analysis, QDs subjected to various optical and physico-chemical characterization methods such as absorption and emission spectra analysis, observation under U.V light, TEM, DLS, Zeta potential, FTIR, Raman and XPS spectra, ICP-OES, TGA and DTG curve. It is very necessary to characterize the synthesized QDs because their toxicity greatly influenced by the physico-chemical properties. On checking the vulnerability of HEK cells on exposure to ZnSe/ZnS QDs, the obtained results disclose that ZnSe/ZnS QDs showed merest impact on cellular viability at a concentration less than 100 μg/ml. Acute toxicity of 10 mg/kg ZnSe/ZnS QDs was studied in mice and no clinical or behavioural changes were observed. It did not induce any changes in haematological parameters and any loss of body or organ weight. Moderate pathological changes were evident only in the liver, all others organs like kidney, spleen and brain did not show any manifestations of toxicity. Current work lays substantial bedrock for safe biomedical and environmental application of ZnSe/ZnS QDs in near future.
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    In vitro and In vivo toxicity analysis of zinc selenium/zinc sulfide (ZnSe/ ZnS) quantum dots
    (Food and Chemical Toxicology, 2020-10) Reshma, VG; Sabareeswaran, A; Rajeev, KS; Mohanan, PV
    Despite the versatility of quantum dots (QDs) in optoelectronics and biomedical field, their toxicity risks remain a considerable hindrance for clinical applications. Cytotoxicity of Cadmium containing QDs is well documented and reveals that they are toxic to cells. Reports suggest that the presence of toxic elements at the QD core (e.g., cadmium, selenium) is responsible for its toxicity in in vivo and in vitro levels. Hence, here the toxicity of heavy metal free ZnSe/ZnS QDs on two scenarios were assessed, (i) HEK cells as in vitro system and (ii) Swiss Albino mice as in vivo model. Before toxicity analysis, QDs subjected to various optical and physico-chemical characterization methods such as absorption and emission spectra analysis, observation under U.V light, TEM, DLS, Zeta potential, FTIR, Raman and XPS spectra, ICP-OES, TGA and DTG curve. It is very necessary to characterize the synthesized QDs because their toxicity greatly influenced by the physico-chemical properties. On checking the vulnerability of HEK cells on exposure to ZnSe/ZnS QDs, the obtained results disclose that ZnSe/ZnS QDs showed merest impact on cellular viability at a concentration less than 100 μg/ml. Acute toxicity of 10 mg/kg ZnSe/ZnS QDs was studied in mice and no clinical or behavioural changes were observed. It did not induce any changes in haematological parameters and any loss of body or organ weight. Moderate pathological changes were evident only in the liver, all others organs like kidney, spleen and brain did not show any manifestations of toxicity. Current work lays substantial bedrock for safe biomedical and environmental application of ZnSe/ZnS QDs in near future.
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    Induction of Cytotoxicity and Oxidative Stress of Dextran Coated Ferrite Nanoparticles (DFNPs) on A549 Cell Lines
    (J of Pharmacol & Clin Res, 2016-12) Reshma, VG; Mohanan, PV
    Super paramagnetic iron oxide nanoparticles have wide range of biomedical applications such as cellular and molecular imaging, site specific drug delivery etc. In the present study, in-house synthesized and characterized nano-size (<25nm) dextran coated ferrite nanoparticles (DFNPs) was subjected to evaluate the cytotoxic potential by using tetrazolium salts MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide using A549 cell lines (human lung carcinoma cell lines), a model of type 2 human alveolar epithelial cells. Similarly, the effects of DFNPs on oxidative stress (reduced glutathione, Glutathione reductase, glutathione peroxidase, superoxide dismutase and lipid peroxidase) using mice lung homogenate were also investigated. Results of the study pointed out that there was a slight fluctuation in antioxidant enzyme activity and lipid peroxidation, and was not significant when compared to control values. DFNPs did not show cytotoxicity up to a concentration of 100µg/ml. Hence, the present study can be concluded that the in-house synthesized DFNPs were non-cytotoxic and promising their use for biomedical applications.
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    Medical Application of Engineered Nanoparticles
    (EC Pharmacology and toxicolog, 2018-03) Reshma, VG; Krishnan, N; Mohanan, PV
    Nanoparticles (NPs) are the particles that exist on a nanometer scale i.e. at least one dimension must be below 100 nm. Due to smaller size, they are highly reactive and show exceptional physical, chemical and optical properties compared to the bulk materials. These remarkable properties make them attractive candidate in various medical applications. Nowadays Nano medicine is a widely developing branch of science which deals with nanoparticle application in medical field. This review highlight the importance of engineered nanoparticles (ENPs) in various medical applications such as drug delivery, antimicrobial agents, photothermal therapy, magnetic hyperthermia, contrast agents in various imaging techniques and biosensors. Currently many NPs are under investigation for drug and gene delivery. Silver, quantum dots (QDs), nano-TiO2 etc. are used as biofilm therapeutic agents. ENPs like QDs act as theranostic agent i.e. they act as both diagnostic as well as therapeutic agent. ENPs have significant role in imaging techniques like MRI, CT scan etc. The risks related with the application of ENPs in various medical applications are not explored much and hence safety evaluation is mandatory before its clinical application.
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    Water dispersible ZnSe/ZnS quantum dots: Assessment of cellular integration, toxicity and bio-distribution
    (Journal of Photochemistry & Photobiology, 2020-11) Reshma, VG; Rajeev, KS; Manoj, K; Mohanan, PV
    Quantum dots (QDs) comprise an emerging group of materials with innumerable number of possibilities in biological research including cellular labelling. Among the leading members in this category, ZnSe/ZnS quantum dots (QDs) hold greater attractive possibilities in imaging primarily due to their higher biocompatibility and dispersibility. Nevertheless, the inherent toxicity of ZnSe/ZnS QDs is not yet completely explored which largely compromise most of their biomedical application potential. Strong blue emitting water soluble QDs effectively synthesized by aqueous phase route. Synthesized QDs further subjected to various optical and physicochemical characterization. Approximately 5–6 nm sized ZnSe/ZnS QDs illuminated bluish green fluorescence under UV lamp. Present study addresses possible adverse effects of ZnSe/ZnS QDs in hepatic system using HepG2 cells; which is the routinely employed in vitroliver cell model. A bundle of assays wasperformed out to reveal the cytotoxic nature of ZnSe/ZnS QDs and the mechanism behind it. Herein, absorption, distribution, metabolism, excretion and toxicity (ADME and T) of ZnSe/ZnS in mice were profiled in detail followed by intravenous (i.v.) and intraperitoneal (i.p.) administration at a dose of 10 mg/kg body weight. In a short review, it could be state that ZnSe/ZnS QDs did not exhibit any significant in vivo toxicity outcome in mice.