W. N. Gade

Nanowires of silver-polyaniline nanocomposite synthesized via in situ polymerization and its novel functionality as an antibacterial agent.

Silver-polyaniline (Ag-PANI) nanocomposite was synthesized by in situ polymerization method using ammonium persulfate (APS) as an oxidizing agent in the presence of dodecylbenzene sulfonic acid (DBSA) and silver nitrate (AgNO(3)). The as synthesized Ag-PANI nanocomposite was characterized by using different analytical techniques such as UV-visible (UV-vis) and Fourier transform Infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). UV-visible spectra of the synthesized nanocomposite showed a sharp peak at ~420 nm corresponding to the surface plasmon resonance (SPR) of the silver nanoparticles (AgNPs) embedded in the polymer matrix which is overlapped by the polaronic peak of polyaniline appearing at that wavelength. Nanowires of Ag-PANI nanocomposite with diameter 50-70 nm were observed in FE-SEM and TEM. TGA has indicated an enhanced thermal stability of nanocomposite as compared to that of pure polymer. The Ag-PANI nanocomposite has shown an antibacterial activity against model organisms, a gram positive Bacillus subtilis NCIM 6633 in Mueller-Hinton (MH) medium, which is hitherto unattempted. The Ag-PANI nanocomposite with monodispersed AgNPs is considered to have potential applications in sensors, catalysis, batteries and electronic devices.

Proteomic and Transcriptomic Analysis of Aspergillus fumigatus on Exposure to Amphotericin B

ABSTRACT Amphotericin B (AMB) is the most widely used polyene antifungal drug for the treatment of systemic fungal infections, including invasive aspergillosis. It has been our aim to understand the molecular targets of AMB in Aspergillus fumigatus by genomic and proteomic approaches. In transcriptomic analysis, a total of 295 genes were found to be differentially expressed (165 upregulated and 130 downregulated), including many involving the ergosterol pathway, cell stress proteins, cell wall proteins, transport proteins, and hypothetical proteins. Proteomic profiles of A. fumigatus alone or A. fumigatus treated with AMB showed differential expression levels for 85 proteins (76 upregulated and 9 downregulated). Forty-eight of them were identified with high confidence and belonged to the above-mentioned categories. Differential expression levels for Rho-GDP dissociation inhibitor (Rho-GDI), secretory-pathway GDI, clathrin, Sec 31 (a subunit of the exocyst complex), and RAB GTPase Ypt51 in response to an antifungal drug are reported here for the first time and may represent a specific response of A. fumigatus to AMB. The expression of some of these genes was validated by real-time reverse transcription-PCR. The AMB responsive genes/proteins observed to be differentially expressed in A. fumigatus may be further explored for novel drug development.

Identification of novel allergens of Aspergillus fumigatus using immunoproteomics approach

Background Approximately 20% of the worlds asthmatics are suffering from Aspergillus fumigatus (Afu)‐induced allergies. The characterization of specific IgE‐inducing allergens in allergic aspergillosis patients is fundamental for clinical diagnosis and for immunotherapy.

Biological Synthesis of Copper Oxide Nano Particles Using Escherichia coli

In this paper, we report a facile biological method for extracellular synthesis of copper oxide nanoparticles (CONPs) using Es- cherichia coli (E. coli). We report that trichloroacetic acid (TCA) precipitated protein fraction of E. coli has synthesized copper oxide nanoparticles (CONPs), under simple experimental conditions like aerobic environment, neutral pH and room temperature. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results have shown that proteins of molecular weight ranging from 22 KDa, 52 KDa, and 25 KDa are not only involved in reduction of Cu (II) into CONPs, but also play a significant role in stabilization of formed nanoparticles at room temperature. Further, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X- ray diffraction measurements (XRD) and fourier transform infrared (FTIR) analysis have confirmed the synthesis of nanoparticles through microbial route. CONPs formed were of variable size and shapes.

Synthesis of Ag-Pt alloy nanoparticles in aqueous bovine serum albumin foam and their cytocompatibility against human gingival fibroblasts.

Foams of bovine serum albumin (BSA) have been utilized for synthesizing in situ protein capped Ag-Pt alloy nanoparticles. The in vitro cytotoxicity and the rate of proliferation of human gingival fibroblasts (HGFs) in presence of the above synthesized alloy nanoparticles is investigated. Expression profile of protein involved in detoxification, i.e. metallotheonein (MT) were assayed by ELISA and expression of mRNA transcripts by reverse transcription polymerase chain reaction (RT-PCR). Cytotoxicity results suggested that protein capped nano-alloys might be promising candidates for implants and prosthetic material. RT-PCR and ELISA confirmed the expression of MT, in cells treated with the alloy nanoparticles. Morphology variation studied by SEM also confirms that cells treated with alloy nanoparticles present an intact morphology.

Micro-nanopatterning as tool to study the role of physicochemical properties on cell–surface interactions

The current nano-biotechnologies interfacing synthetic materials and cell biology requires a better understanding of cell-surface interactions on the micro-to-nanometer scale. Cell-substrate interactions are mediated by the presence of proteins adsorbed from biological fluids to the substrate. The effect of nanotopography and surface chemistry on protein adsorption as well as the mediation effect on subsequent cellular communication with substratum is not well documented. This review discusses the role of physicochemical properties of cell-surface interactions and state-of-the-art methods currently available for micro-nanoscale surface fabrication and patterning. We also briefly discuss the current surface patterning techniques that allow the combination of a fine and independent control on nanotopography and chemistry to understand the effect of surface nanoscale substrate morphology on cell-surface interactions which has never been realized in previous reports. In addition, we discuss the influence of various chemical patterning and modulation of the nano-topography of surfaces on cell functionality and phenotype.

Theranostic Implications of Nanotechnology in Multiple Sclerosis: A Future Perspective

Multiple Sclerosis is a multifactorial disease with several pathogenic mechanisms and pathways. Successful MS management and medical care requires early accurate diagnosis along with specific treatment protocols based upon multifunctional nanotechnology approach. This paper highlights advances in nanotechnology that have enabled the clinician to target the brain and CNS in patient with multiple sclerosis with nanoparticles having therapeutic and imaging components. The multipartite theranostic (thera(py) + (diag)nostics) approach puts forth strong implications for medical care and cure in MS. The current nanotheranostics utilize tamed drug vehicles and contain cargo, targeting ligands, and imaging labels for delivery to specific tissues, cells, or subcellular components. A brief overview of nonsurgical nanorepair advances as future perspective is also described. Considering the potential inflammatory triggers in MS pathogenesis, a multifunctional nanotechnology approach will be needed for the prognosis.

Biofilm inhibition of linezolid-like Schiff bases: synthesis, biological activity, molecular docking and in silico ADME prediction.

Herein, we report the synthesis and screening of linezolid-like Schiff bases as inhibitors of biofilm formation. The result of biofilm inhibition of Pseudomonas aeruginosa suggested that compounds 5h (IC50 value=12.97±0.33μM) and 5i (IC50 value=15.63±0.20μM) had more inhibitory activity when compared with standard linezolid (IC50=15.93±0.18μM) without affecting the growth of cells (and thus behave as anti-quorum sensing agents). The compounds 5h (MIC range=2.5-10μg/mL) and 5i (MIC range=3.5-10μg/mL) with 2-chloroquinolinyl and 2-chloro-8-methylquinolinyl motif, respectively, showed antibacterial activity in comparable range of linezolid (MIC range=2-3μg/mL) and were more potent when compared with ciprofloxacin (MIC range=25-50μg/mL). Thus, the active derivatives were not only potent inhibitors of P. aeruginosa biofilm growth but also efficient antibacterial agents. The docking study of most active compounds 5h and 5i against PqsD enzyme of P. aeruginosa exhibited good binding properties. In silico ADME properties of synthesized compounds were also analyzed and showed potential to develop as good oral drug candidates.

Xylitol production by Cyberlindnera (Williopsis) saturnus, a tropical mangrove yeast from xylose and corn cob hydrolysate

Potential for xylitol production from xylose and corn cob hydrolysate by a tropical mangrove yeast.

Innovative biofilm inhibition and anti-microbial behavior of molybdenum sulfide nanostructures generated by microwave-assisted solvothermal route

The incessant use of antibiotics against infectious diseases has translated into a vicious circle of developing new antibiotic drug and its resistant strains in short period of time due to inherent nature of micro-organisms to alter their genes. Many researchers have been trying to formulate inorganic nanoparticles-based antiseptics that may be linked to broad-spectrum activity and far lower propensity to induce microbial resistance than antibiotics. The way-out approaches in this direction are nanomaterials based (1) bactericidal and (2) bacteriostatic activities. We, herein, present hitherto unreported observations on microbial abatement using non-cytotoxic molybdenum disulfide nanostructures (MSNs) which are synthesized using microwave assisted solvothermal route. Inhibition of biofilm formation using MSNs is a unique feature of our study. Furthermore, this study evinces antimicrobial mechanism of MSNs by reactive oxygen species (ROS) dependent generation of superoxide anion radical via disruption of cellular functions.