Khargāpur, India
Khargāpur, India

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Chattopadhyay S.,Vidyasagar University | Dash S.K.,Vidyasagar University | Kar Mahapatra S.,SASTRA University | Tripathy S.,Vidyasagar University | And 5 more authors.
Journal of Biological Inorganic Chemistry | Year: 2014

The objective of this study was to develop chitosan-based delivery of cobalt oxide nanoparticles to human leukemic cells and investigate their specific induction of apoptosis. The physicochemical properties of the chitosan-coated cobalt oxide nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, X-ray diffraction, and Fourier transform infrared spectroscopy. The solubility of chitosan-coated cobalt oxide nanoparticles was higher at acidic pH, which helps to release more cobalt ions into the medium. Chitosan-coated cobalt oxide nanoparticles showed good compatibility with normal cells. However, our results showed that exposure of leukemic cells (Jurkat cells) to chitosan-coated cobalt oxide nanoparticles caused an increase in reactive oxygen species generation that was abolished by pretreatment of cells with the reactive oxygen species scavenger N-acetyl-L-cysteine. The apoptosis of Jurkat cells was confirmed by flow-cytometric analysis. Induction of TNF-α secretion was observed from stimulation of Jurkat cells with chitosan-coated cobalt oxide nanoparticles. We also tested the role of TNF-α in the induction of Jurkat cell death in the presence of TNF-α and caspase inhibitors. Treatment of leukemic cells with a blocker had a greater effect on cancer cell viability. From our findings, oxidative stress and caspase activation are involved in cancer cell death induced by chitosan-coated cobalt oxide nanoparticles. © SBIC 2014.


Sharma B.,Assam University | Purkayastha D.D.,Assam University | Hazra S.,Nano Materials Laboratory | Thajamanbi M.,Assam University | And 3 more authors.
Bioprocess and Biosystems Engineering | Year: 2014

Biosynthesis of gold nanoparticles has been accomplished via reduction of an aqueous chloroauric acid solution with the dried biomass of an edible freshwater epilithic red alga, Lemanea fluviatilis (L.) C.Ag., as both reductant and stabilizer. The synthesized nanoparticles were characterized by UV-visible, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), and dynamic light scattering (DLS) studies. The UV-visible spectrum of the synthesized gold nanoparticles showed the surface plasmon resonance (SPR) at around 530 nm. The powder XRD pattern furnished evidence for the formation of face-centered cubic structure of gold having average crystallite size 5.9 nm. The TEM images showed the nanoparticles to be polydispersed, nearly spherical in shape and have sizes in the range 5-15 nm. The photoluminescence spectrum of the gold nanoparticles excited at 300 nm showed blue emission at around 440 nm. Gold nanoparticles loaded within the biomatrix studied using a modified 2,2-diphenyl-1-picrylhydrazyl (DPPH) method exhibited pronounced antioxidant activity. © 2014 Springer-Verlag Berlin Heidelberg.


Debnath R.,Assam University | Purkayastha D.D.,Assam University | Hazra S.,Nano Materials Laboratory | Ghosh N.N.,Nano Materials Laboratory | And 2 more authors.
Materials Letters | Year: 2016

Biogenic synthesis of gold nanoparticles have been accomplished using dried biomass of two high altitude lichen species, collected from the alpine region of Eastern Himalaya in Arunachal Pradesh state of North East India, without addition of any external reducing or stabilizing chemicals. The nanoparticles were characterised by UV-visible, FT-IR spectroscopy, powder X-ray diffraction (XRD), and transmission electron microscopy (TEM). The as-obtained gold nanoparticles showed surface plasmon resonance (SPR) band at ~535 nm. The XRD study furnished evidence for the formation of face-centered cubic structure of gold nanomaterials. The nanoparticles produced with Acroscyphus sp. consisted of multiply twinned quasi-spherical and prismatic shapes while those accessed with Sticta sp. are exclusively multiply twinned. The biomatrix loaded gold nanomaterial exhibited pronounced antioxidant activity. © 2016 Elsevier B.V. All rights reserved.


Sharma B.,Assam University | Purkayastha D.D.,Assam University | Hazra S.,Nano Materials Laboratory | Gogoi L.,Assam University | And 3 more authors.
Materials Letters | Year: 2014

Biosynthesis of gold nanoparticles has been achieved via reduction of an aqueous chloroauric acid solution with dried biomass of a freshwater epilithic green alga, Prasiola crispa, collected from a high altitude river ecosystem in Arunachal Pradesh state, India. The synthesized nanoparticles were characterized by UV-visible, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR, and DLS studies. The UV-visible spectrum of the synthesized gold nanoparticles showed a surface plasmon resonance (SPR) around 535 nm after 12 h. The powder XRD pattern furnished evidence for the formation of face-centered cubic structure of gold having average crystallite size 9.8 nm. The TEM images showed the nanoparticles to be nearly spherical in shape with sizes in the range of 5-25 nm. © 2013 Elsevier B.V.


Chattopadhyay S.,Vidyasagar University | Dash S.K.,Vidyasagar University | Tripathy S.,Vidyasagar University | Das B.,Vidyasagar University | And 3 more authors.
Journal of Applied Toxicology | Year: 2015

The purpose of this study was to determine the intracellular signaling transduction pathways involved in oxidative stress induced by nanoparticles in cancer cells. Activation of reactive oxygen species (ROS) has some therapeutic benefits in arresting the growth of cancer cells. Cobalt oxide nanoparticles (CoO NPs) are an interesting compound for oxidative cancer therapy. Our results showed that CoO NPs elicited a significant (P <0.05) amount of ROS in cancer cells. Co-treatment with N-aceyltine cystine (an inhibitor of ROS) had a protective role in cancer cell death induced by CoO NPs. In cultured cells, the elevated level of tumor necrosis factor-alpha (TNF-α) was noted after CoO NPs treatment. This TNF-α persuaded activation of caspase-8 followed by phosphorylation of p38 mitogen-activated protein kinase and induced cell death. This study showed that CoO NPs induced oxidative stress and activated the signaling pathway of TNF-α-Caspase-8-p38-Caspase-3 to cancer cells. © 2015 John Wiley & Sons, Ltd.


Chattopadhyay S.,Vidyasagar University | Dash S.K.,Vidyasagar University | Tripathy S.,Vidyasagar University | Pramanik P.,Nano Materials Laboratory | Roy S.,Vidyasagar University
Journal of Biological Inorganic Chemistry | Year: 2015

The aim of this work is to understand the potential health effects of metal nanoparticles by exposing human leukemic cell lines (jurkat, K562 and KG1A cells) to nanosize phosphonomethyl iminodiacetic acid coated cobalt oxide (PMIDA-CoO) NPs. The synthesized PMIDA-CoO NPs were characterized by XRD, dynamic light scattering, transmission electron microscopy and scanning electron microscopy. Our results showed that exposure of leukemic cell lines to PMIDA-CoO NPs caused reactive oxygen species (ROS) generation by increasing the concentration of free Co++ ions in cancer microenvironment. But at physiological pH, PMIDA-CoO liberates little amount of Co++ ions into media and exerts lower toxicity to normal cells up to a certain dose. PMIDA-CoO NPs caused DNA damage in leukemic cell lines, which was reflected by an increase in apoptosis of jurkat, KG-1A and K562 cells. PMIDA-CoO NPs induced apoptosis by increasing pro-inflammatory cytokines, primarily TNF-α. The in vivo study shows that PMIDA-CoO NPs were efficiently killed DLA cells. These findings have important implications for understanding the potential anticancer property induced by surface-modified cobalt oxide nanoparticles. © 2014 SBIC.


Rajput A.B.,Nano Materials Laboratory | Hazra S.,Nano Materials Laboratory | Krishna N.B.,Nano Materials Laboratory | Chavali P.,Nano Materials Laboratory | And 2 more authors.
Particuology | Year: 2012

An ethylene diamine tetra acetic acid (EDTA) precursor-based chemical method is reported for preparing single-phase nickel ferrite (NiFe 2O 4) nanopowder. The synthesized powder was characterized by thermogravimetric analysis, differential scanning calorimetric analysis, X-ray diffraction, particle size analysis and scanning electron microscopy. DC electrical resistivity and magnetic property of the synthesized NiFe 2O 4 were measured by using a two-probe method and a vibrating sample magnetometer respectively. The DC resistivity behaviour of the NiFe 2O 4 nanopowder was correlated with the change of microstructure, during sintering. This EDTA precursor-based method is capable of producing nanostructured single-phase NiFe 2O 4 powder at a comparatively low calcination temperature and offers the potential of a simple and cost-effective route, including the preparation of other ferrite nanoparticles. © 2011 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

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