Browsing by Author "Bose, R."

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    Calcium oxalate degrading thermophilic oxalate oxidase from newly isolated Fusarium oxysporum RBP3
    (Elsevier Ltd, 2020) Kizhakedathil, M.P.; Bose, R.; Belur, P.D.
    Four oxalate oxidase (OxO) positive fungal strains were isolated from rotting taro corms. One isolate showing highest extra cellular OxO titre was selected and was identified based on partial sequencing of 18S rRNA. The selected strain was found to be Fusarium oxysporum f. sp. cumini. Oxalate oxidase (EC 1.2.3.4) titre was increased by one factor at a time approach in shake flasks. The enzyme was then purified by isopropanol precipitation followed by chromatography using ENrich SEC650 FPLC column. OxO was found to be a heterodimer having two subunits of mass 116 and 105 kDa. Optimum pH and temperature were found to be 3.8 and 80 °C respectively. OxO exhibited stability for 4 h at temperature range of 4–95 °C and pH between 2.2 and 10.0. OxO was inactive until 30 °C and more than 90% of its peak activity was observed at temperature above 80 °C, suggesting that the enzyme is thermophilic. OxO appears to be a metalloprotein inhibited by Cu2+, Fe2+ and EDTA and enhanced in the presence of Mn2+ and biotin. OxO also exhibited broad substrate specificity. This enzyme was found to decompose insoluble calcium oxalate crystals. This is the first report of OxO decomposing calcium oxalate crystals. © 2020
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    Differential delivery of vincristine to A549 cells using Chitosan capped silver nanoparticles under the pH trigger
    (2017) Varadharajan, V.; Ramaswamy, A.; Bose, R.; Arumugam, G.K.S.
    This study reports chitosan capped biogenically synthesized silver nanoparticles (Chit@AgNPs) of Diameter=12 nm for efficient delivery of vincristine (VCR) to A549 cells under the pH trigger. About 48% w/w of VCR could be loaded to Chit@AgNP without any conjugation system. The infrared spectroscopy indicated the presence of abundant quantities of the hydroxyl group on the surface of VCR loaded Chit@AgNP and it was confirmed by its negative zeta potential (-11.7 mV). Under in vitro condition, the release of VCR from Chit@AgNP into aqueous solution strictly followed first order kinetics with high preference to acidic pH. Significant cytotoxicity was observed in A549 cells than MDCK cells at p > 0-05 when incubated with VCR loaded Chit@AgNP, promoting high specificity towards cancer cells.
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    Differential delivery of vincristine to A549 cells using Chitosan capped silver nanoparticles under the pH trigger
    (American Scientific Publishers order@aspbs.com, 2017) Venkatramanan, V.; Arulvel, A.; Bose, R.; Arumugam, G.K.S.
    This study reports chitosan capped biogenically synthesized silver nanoparticles (Chit@AgNPs) of Diameter=12 nm for efficient delivery of vincristine (VCR) to A549 cells under the pH trigger. About 48% w/w of VCR could be loaded to Chit@AgNP without any conjugation system. The infrared spectroscopy indicated the presence of abundant quantities of the hydroxyl group on the surface of VCR loaded Chit@AgNP and it was confirmed by its negative zeta potential (-11.7 mV). Under in vitro condition, the release of VCR from Chit@AgNP into aqueous solution strictly followed first order kinetics with high preference to acidic pH. Significant cytotoxicity was observed in A549 cells than MDCK cells at p > 0-05 when incubated with VCR loaded Chit@AgNP, promoting high specificity towards cancer cells.