Polychlorinated Biphenyls (PCBs) in the Bio-geochemistry of Oceans

Narayanan Kannan 한국해양바이오학회 2007 한국해양바이오학회지 Vol.2 No.4

Unnatural amino acid-mediated synthesis of silver nanoparticles and their antifungal activity against Candida species

Narayanan, Kannan Badri,Park, Hyun Ho Springer-Verlag 2014 JOURNAL OF NANOPARTICLE RESEARCH Vol.16 No.8

Purification and analysis of the interactions of caspase-1 and ASC for assembly of the inflammasome.

Narayanan, Kannan Badri,Park, Hyun Ho Humana Press 2015 Applied biochemistry and biotechnology Vol.175 No.6

<P>Inflammasomes are intracellular macromolecular complexes assembled to activate inflammatory caspases such as caspase-1 and caspase-5, which perform critical roles during innate immune response. The NALP3 inflammasome comprises three protein components, NALP3, ASC, and caspase-1. ASC, which contains both a pyrin domain (PYD) and a caspase recruitment domain (CARD), acts as a bridge to recruit NALP3 using the PYD/PYD interaction and to recruit caspase-1 via the CARD/CARD interaction. In this study, we successfully purified and characterized ASC CARD and caspase-1 CARD. The results showed that ASC CARD was unable to interact with caspase-1 CARD in vitro; therefore, we proposed an interaction mode between ASC CARD and caspase-1 CARD from a structural based modeling study.</P>

Anti-tumor and Chemoprotective Effect of Bauhinia tomentosa by Regulating Growth Factors and Inflammatory Mediators

Kannan, Narayanan,Sakthivel, Kunnathur Murugesan,Guruvayoorappan, Chandrasekaran Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.18

Cancer is a leading cause of death worldwide. Due to the toxic side effects of the commonly used chemotherapeutic drug cyclophosphamide (CTX), the use of herbal medicines with fewer side effects but having potential use as inducing anti-cancer outcomes in situ has become increasingly popular. The present study sought to investigate the effects of a methanolic extract of Bauhinia tomentosa against Dalton's ascites lymphoma (DAL) induced ascites as well as solid tumors in BALB/c mice. Specifically, B. tomentosa extract was administered intraperitonealy (IP) at 10 mg/kg. BW body weight starting just after tumor cell implantation and thereafter for 10 consecutive days. In the ascites tumor model hosts, administration of extract resulted in a 52% increase in the life span. In solid tumor models, co-administration of extract and CTX significantly reduced tumor volume (relative to in untreated hosts) by 73% compared to just by 52% when the extract alone was provided. Co-administration of the extract also mitigated CTX-induced toxicity, including decreases in WBC count, and in bone marrow cellularity and ${\alpha}$-esterase activity. Extract treatment also attenuated any increases in serum levels of $TNF{\alpha}$, iNOS, IL-$1{\beta}$, IL-6, GM-CSF, and VEGF seen in tumor-bearing hosts. This study confirmed that, the potent antitumor activity of B.tomentosa extract may be associated with immune modulatory effects by regulating anti-oxidants and cytokine levels.

Biosynthesis of Silver Nanoparticles by Phytopathogen Xanthomonas oryzae pv. oryzae Strain BXO8

( Kannan Badri Narayanan ),( Natarajan Sakthivel ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.9

Extracellular biogenic synthesis of silver nanoparticles with various shapes using the rice bacterial blight bacterium Xanthomonas oryzae pv. oryzae BXO8 is reported. The synthesized silver nanoparticles were characterized by UV-Vis spectroscopy, powder X-ray diffractometry (XRD), scanning electron microscopy, energy dispersive X-ray spectrometry, and highresolution transmission electron microscopy (HR-TEM). Based on the evidence of HR-TEM, the synthesized particles were found to be spherical, with anisotropic structures such as triangles and rods, with an average size of 14.86 nm. The crystalline nature of silver nanoparticles was evident from the bright circular spots in the SAED pattern, clear lattice fringes in the high-resolution TEM images, and peaks in the XRD pattern. The FTIR spectrum showed that biomolecules containing amide and carboxylate groups are involved in the reduction and stabilization of the silver nanoparticles. Using such a biological method for the synthesis of silver nanoparticles is a simple, viable, cost-effective, and environmentally friendly process, which can be used in antimicrobial therapy.

Toll/interleukin-1 receptor (TIR) domain-mediated cellular signaling pathways.

Narayanan, Kannan Badri,Park, Hyun Ho Rapid Science Publishers ; Kluwer Academic Publish 2015 Apoptosis Vol.20 No.2

<P>Innate immunity, which is the first line of host defense against invading microbial pathogens in multicellular organisms, occurs through germline-encoded pattern-recognition receptors. The Toll-like receptor/Interleukin (IL)-1 receptor (TLR/IL-1R) superfamily comprises proteins that contain the phylogenetically conserved Toll/IL-1 receptor (TIR) domain, which is responsible for the propagation of downstream signaling through recruitment of TIR domain containing cytosolic adaptor proteins such as MyD88, TIRAP/MAL, TRIF, TRAM and SARM. These interactions activate transcription factors that regulate the expression of various proinflammatory cytokines (IL-1, IL-6, IL-8 and TNF-관) and chemokines. Activation of the TLR/IL-1R signaling pathway promotes the onset of inflammatory diseases, autoimmune diseases and cancer; therefore, this pathway can be used for the development of therapeutic strategies against these types of pathogenesis. In this review paper, we illustrate the role of the TIR-TIR domain interaction with the TLR/IL-1R signaling pathway in inflammation and apoptosis and recent therapeutic drugs targeted to inhibit the downstream signaling cascade for treatment of inflammatory diseases and cancer.</P>

Biofabrication of <i>Lysinibacillus sphaericus</i>-reduced graphene oxide in three-dimensional polyacrylamide/carbon nanocomposite hydrogels for skin tissue engineering

Narayanan, Kannan Badri,Choi, Soon Mo,Han, Sung Soo Elsevier 2019 Colloids and Surfaces B Vol.181 No.-

<P><B>Abstract</B></P> <P>The biological synthesis of reduced graphene oxide (rGO) from graphene oxide (GO) is an emerging phenomenon for developing biocompatible nanomaterials for its potential applications in nanomedicine. In this study, we demonstrated a simple, green, and non-toxic method for graphene synthesis using the live biomass of <I>Lysinibacillus sphaericus</I> as the reducing and stabilizing agent under ambient conditions. Ultraviolet-visible spectroscopic analysis confirmed the formation of graphene from GO suspension. X-ray diffraction studies showed the disappearance of the GO peak and the appearance of characteristic graphene broad peak at 2θ = 22.8°. Infrared analysis showed the decrease/disappearance of peaks corresponding to the oxygen-containing functionalities, and appearance of a peak at 1620 cm<SUP>–1</SUP> from unoxidized graphitic domains. Scanning electron microscopic images showed that <I>L. sphaericus</I>-reduced graphene oxide (L-rGO) contains aggregated graphene nanoflakes. Evaluation of the <I>in vitro</I> cytotoxicity of L-rGO nanosheets on human skin fibroblasts using the WST-1 assay did not show any significant effects after 24 h of exposure, which is indicative of biocompatibility. Polyacrylamide hydrogels with L-rGO were synthesized and used as scaffolds to support the growth and proliferation of skin fibroblasts. Cell viability assays and DAPI staining showed proliferation of fibroblasts and exhibited 83% of cell viability even after 28 days. Biofilm formation by <I>Pseudomonas aeruginosa</I> and <I>Staphylococcus aureus</I> was enhanced in nanocomposite hydrogels in the presence of 0.25 mg/mL GO and L-rGO in 48 h. Overall, this study showed that microbially-synthesized L-rGO can be used as a dopant in polymeric scaffolds for tissue engineering and highlighted their role in biofilm formation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Carbon-based hydrogels with enhanced mechanical properties can be used for tissue engineering. </LI> <LI> Microbial synthesis of reduced graphene oxide using <I>L. sphaericus</I> (L-rGO) bacterium was done. </LI> <LI> L-rGO incorporated into three-dimensional (3D) polyacrylamide (PAAm/L-rGO) hydrogel. </LI> <LI> PAAm/L-rGO nanocomposite hydrogels showed biocompatibility towards human skin fibroblasts. </LI> <LI> PAAm/L-rGO showed enhanced bacterial biofilm formation by <I>P. aeruginosa</I> and <I>S. aureus</I>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Polychlorinated Biphenyls (PCBs) in the Bio-geochemistry of Oceans

Kannan, Narayanan The Korean Society for Marine Biotechnology 2007 한국해양바이오학회지 Vol.2 No.4

Polychlorinated biphenyls (PCBs) are anthropogenic contaminants found globally in water, ice, soil, air and sediment. Modern analytical techniques allow us to determine these chemicals in environmental matrices at parts per trillion levels or lower. Environmental forensic on PCBs opens up new avenues of investigation such as transport and fate of water masses in oceans, sedimentation, onset of primary production, migration of marine mammals, their population distribution and pharmacokinetics of drugs inside organisms. By virtue of persistence, bioaccumulation, bioconcentration and structure-activity relationship PCBs emerge as unconventional chemical tracers of new sort.

Helical plant viral nanoparticles-bioinspired synthesis of nanomaterials and nanostructures

Narayanan, Kannan Badri,Han, Sung Soo IOP Publishing 2017 Bioinspiration & biomimetics Vol.12 No.3

<P>Viral nanotechnology is revolutionizing the biomimetic and bioinspired synthesis of novel nanomaterials. Bottom-up nanofabrication by self-assembly of individual molecular components of elongated viral nanoparticles (VNPs) and virus-like particles (VLPs) has resulted in the production of superior materials and structures in the nano(bio) technological fields. Viral capsids are attractive materials, because of their symmetry, monodispersity, and polyvalency. Helical VNPs/VLPs are unique prefabricated nanoscaffolds with large surface area to volume ratios and high aspect ratios, and enable the construction of exquisite supramolecular nanostructures. This review discusses the genetic and chemical modifications of outer, inner, and interface surfaces of a viral protein cage that will almost certainly lead to the development of superior next-generation targeted drug delivery and imaging systems, biosensors, energy storage and optoelectronic devices, therapeutics, and catalysts.</P>

Dual-crosslinked poly(vinyl alcohol)/sodium alginate/silver nanocomposite beads – A promising antimicrobial material

Narayanan, Kannan Badri,Han, Sung Soo Elsevier 2017 Food chemistry Vol.234 No.-

<P><B>Abstract</B></P> <P>In this paper, we report the immobilization of borate-stabilized silver nanoparticles (AgNPs) as nanofillers in dual-crosslinked polymers comprised of poly(vinyl alcohol) (PVA) and sodium alginate (SA) at different ratios. Ionic-crosslinking using Ca<SUP>2+</SUP> ions and physical-crosslinking by freeze-thawing were used to entrap silver nanoparticles in the prepared PVA/SA/AgNPs nanocomposite beads. These polymeric nanocomposites were characterized by UV–Vis, XRD, FE–SEM, FT-IR, TGA, and using rheological and swelling properties. The antibacterial activities of these PVA/SA/AgNPs nanocomposites were evaluated against <I>Escherichia coli</I> O157: H7, which causes escherichiosis through contaminated food and water. The results obtained indicated that PVA/SA/AgNPs nanocomposite formed with a ratio 10/90 of PVA to SA (formulation F5) exhibited high bactericidal activity, with entrapment of AgNPs and had excellent rheological and thermal stabilities. Due to the low cost and effectiveness of these antimicrobial nanocomposites, they have potential as an active food-packaging material for food safety and to extend shelf-life of packaged foods.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Antimicrobial polymeric/metal nanocomposites can be used in active food packaging. </LI> <LI> PVA and SA at different ratios were used to prepare various PVA/SA/AgNPs composites. </LI> <LI> Dual-crosslinking of polymer/silver nanocomposites entraps silver nanoparticles. </LI> <LI> <I>Escherichia coli</I> (∼10<SUP>11</SUP> CFU/ml) were killed by PVA/SA/AgNPs beads in batch culture. </LI> <LI> Effective killing of <I>E. coli</I> (∼10<SUP>8</SUP> CFU/ml) cells in contact with PVA/SA/AgNPs surface. </LI> </UL> </P>