Faculty Publications
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Item Solid Phase PEGylation of Uricase(Elsevier Ltd, 2017) Nanda, P.; JagadeeshBabu, P.E.Uricase is used as a therapeutic enzyme to treat gout and hyperuricemia which also finds application in cancer chemotherapy. Site-specific PEGylation of uricase using methoxy polyethylene glycol maleimide (mPEG-mal) through thiol PEGylation reaction is an effective way to overcome the demerit of its short plasma half-life in blood as well as for the enhancement of its therapeutic potential. However, conventional solution-phase PEGylation for the synthesis of conjugates leads to lower yields of the desired PEGylated product and thus falls short of commercial attraction. In order to preserve the bioactivity of PEGylated product, selectivity, and extent of covalent conjugation, a methodology for on-column/solid phase PEGylation of uricase enzyme using size-exclusion reaction chromatography (SERC) has been attempted. Sephadex G-100 was used as a chromatographic solid media, wherein synthesis of mono and di-PEGylated uricase molecules was observed which were efficiently separated from their non-PEGylated counterparts. © 2017 Elsevier Ltd.Item An overview of the density functional theory on antioxidant bioactivity predictive feasibilities: Insights from natural antioxidant products(Elsevier B.V., 2024) Shaker, L.M.; A Al-Amiery, A.A.; Abed, T.K.; Khalid Al-Azzawi, W.K.; Kadhum, A.A.H.; Sulaiman, G.M.; Mohammed, H.A.; Khan, M.; Khan, R.A.Antioxidants play a crucial role in protecting biological systems from oxidative stress, which is implicated in a wide range of diseases. Computational methods have become increasingly valuable in studying the mechanisms of antioxidants, with density functional theory (DFT) being a popular approach. This review provides an overview of the theoretical basis of DFT and its application to molecular systems. It discusses the advantages and limitations of using DFT for studying antioxidants and explores the relationship between antioxidant activity and molecular structure. The paper also highlights the importance of solvation effects in determining antioxidant efficacy and suggests DFT-based methods for incorporating solvation effects into calculations. Case studies of specific antioxidants are presented to illustrate the role of the solvent environment in determining the antioxidant efficacy. Finally, it discusses the relationship between antioxidant activity and certain DFT parameters, and suggests future directions for research. Overall, this review provides valuable insights into the use of DFT in studying antioxidants, and sheds light on the future of computational studies in this field. © 2023Item Synthesis, characterization and antibacterial activity of some new pyrazole based Schiff bases(2013) Malladi, S.; Isloor, A.M.; Isloor, S.; Akhila, D.S.; Fun, H.-K.In the present study a series of new Schiff bases were synthesized. All the synthesized compounds were characterized by IR, 1H NMR, mass spectral and elemental analyses. Newly synthesized compounds were screened for their antibacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa) activity. The results revealed that, compounds 3f and 3c have exhibited significant biological activity against the tested microorganisms. © 2011.Item Substituted quinoline derivatives as potent biological agents(Trans Tech Publications Ltd ttp@transtec.ch, 2014) Garudacharia, B.; Isloora, A.M.Quinoline derivatives are the most promising class of active pharmaceutical agents compared with other heterocyclic compounds. Biological activity profile of quinoline can easily be controlled by introducing some active pharmacophore to the core ring. This chapter deals with the synthesis of quinoline derivatives and its biological activity. The enhancement of biological activity by incorporation of active functional group and effect of these functional groups were explained briefly. Main focus is given to the synthesis of different substituted quinoline derivatives for biological application with respect to the position on the quinoline core ring and modification of quinoline ring. © (2014) Trans Tech Publications, Switzerland.Item Synthesis and in vitro biological evaluation of new pyrazole chalcones and heterocyclic diamides as potential anticancer agents(Elsevier B.V., 2015) Sankappa Rai, U.; Isloor, A.M.; Shetty, P.; Pai, K.S.R.; Fun, H.-K.Synthesis and characterization of new heterocyclic pyrazole chalcones (4a-. e) and diamide (6a-. e) derivatives are described. Pyrazole chalcones were synthesized by the reaction of pyrazole aldehydes and suitable aromatic ketones. Diamides were synthesized by the reaction of phthalic acid and amines. Newly synthesized compounds were characterized by spectral studies and their biological activity was assessed in vitro using MCF-7 (human breast adenocarcinoma) and HeLa (human cervical tumor cells) cell lines. Few of the synthesized molecules inhibited the growth of the human breast cancer cell lines and human cervical tumor cell lines at low micromolar to nanomolar concentrations. © 2014 King Saud University.Item Dissolution and in vitro bioactive properties of BaO added Na2O-CaO-P2O5 glasses(Society of Glass Technology christine@glass.demon.co.uk, 2018) Edathazhe, A.B.; Shashikala, H.D.Na2O-CaO-P2O5 glasses with different additions of BaO were subjected to dissolution tests in deionised water and in vitro bioactivity tests in phosphate buffer saline (PBS) as well as Hank's balanced salt (HBS) solution. Phosphate glasses of composition (26-x)Na2O-xBaO-29CaO-45P2O5 (x=0, 5, 10, 15 mol%) were prepared by melt-quenching. The dissolution characteristics of these glasses were studied in deionised water under static conditions based on BaO composition. The dissolution rate of the glasses in deionised water decreased with BaO content. The in vitro bioactivity tests were carried out in PBS and HBSS for 28 days under static conditions. The bioactivity of the samples was verified by XRD, SEM/EDS and FTIR techniques. Hydroxyapatite phases were formed on all the glass samples within seven days of immersion in HBSS and the bioactivity was found to improve with BaO content. The glasses without BaO and with 15 mol% BaO showed the hydroxyapatite phases within the immersion of 14 days in PBS whereas the glasses with 5 and 10 mol% BaO showed formation of amorphous hydroxyapatite phases. © 2018 Society of Glass Technology. All rights reserved.Item Corrosion resistance and in-vitro bioactivity of BaO containing Na2O-CaO-P2O5 phosphate glass-ceramic coating prepared on 316 L, duplex stainless steel 2205 and Ti6Al4V(Institute of Physics Publishing helen.craven@iop.org, 2018) Edathazhe, A.B.; Shashikala, H.D.The phosphate glass with composition 11Na2O-15BaO-29CaO-45P2O5 was coated on biomedical implant materials such as stainless steel 316 L, duplex stainless steel (DSS) 2205 and Ti6Al4V alloy by thermal enamelling method. The structural properties and composition of glass coated substrates were studied by x-ray diffraction (XRD), Scanning electron microscopy (SEM) and Energy dispersive x-ray spectroscopy (EDS) analysis. The coatings were partially crystalline in nature with porous structure and pore size varied from micro to nanometer range. The polarization curve was obtained for uncoated and coated substrates from electrochemical corrosion test which was conducted at 37 °C in Hank's balanced salt solution (HBSS). The corrosion resistance of 316 L substrate increased after coating, whereas it decreased in case of DSS 2205 and Ti6Al4V. The XRD and SEM/EDS studies indicated the bioactive hydroxyapatite (HAp) layer formation on all the coated surfaces after electrochemical corrosion test, which improved the corrosion resistance. The observed electrochemical corrosion behavior can be explained based on protective HAp layer formation, composition and diffusion of ions on glass coated surfaces. The in-vitro bioactivity test was carried out at 37 °C in HBS solution for 14 days under static conditions for uncoated and coated substrates. pH and ion release rate measurements from the coated samples were conducted to substantiate the electrochemical corrosion test. The lower ion release rates of Na+ and Ca2+ from coated 316 L supported its higher electrochemical corrosion resistance among coated samples. Among the uncoated substrates, DSS showed higher electrochemical corrosion resistance. Amorphous calcium-phosphate (ACP) layer formation on all the coated substrates after in-vitro bioactivity test was confirmed by XRD, SEM/EDS and ion release measurements. The present work is a comparative study of corrosion resistance and bioactivity of glass coated and uncoated biomedical implants such as 316 L, DSS and Ti6Al4V. © 2018 IOP Publishing Ltd.Item Development and Characterization of Biomedical Porous Ti–20Nb–5Ag Alloy: Microstructure, Mechanical Properties, Surface Bioactivity and Cell Viability Studies(Korean Institute of Metals and Materials, 2022) Shivaram, M.J.; Arya, S.B.; Nayak, J.; Panigrahi, B.B.Abstract: In this study, antibacterial Ag element added to synthesis of porous Ti–20Nb–5Ag (wt%) alloy using powder metallurgy space holder route. The microstructural, mechanical property, surface bioactivity and cytotoxicity behavior of porous Ti–20Nb–5Ag alloy have been investigated. The developed porous alloy obtained the porosities ranging from 22.5 to 68%. The porous sample having a porosity of about 43% is found to be in the optimum condition, which possess a modulus of about 5.8 GPa with an excellent compressive strength about 205 MPa. XRD result shows that the formation of small amount of α-Ti, β-Ti, along with α״ martensite and Ti2Ag are key phase constituents of sintered porous Ti–20Nb–5Ag alloys. The compression strength and elastic modulus of the sintered alloys were showed that decreased with increase of porosity. Surface bioactivity result revealed that the significant formation of hydroxyapatite on the alkali-heat treated (5 M NaOH) porous Ti–20Nb–5Ag alloy which is found after the in vitro test in SBF. Further, the cell viability test was conducted on as-synthesized porous Ti–20Nb–5Ag alloy for 1, 4, and 7 days using MG-63 human osteoblast cells and result shows an excellent cell proliferation, and the cytotoxicity test confirms the non-toxic nature of the porous alloy which is very much suitable for implant application. Graphic Abstract: [Figure not available: see fulltext.]. © 2021, The Korean Institute of Metals and Materials.Item Degradation response and bioactivity assessment of antimicrobial copper coatings in simulated hand sweat environment(Elsevier B.V., 2022) Bharadishettar, N.; Udaya Bhat, K.The antimicrobial copper coatings were deposited on AISI 304 stainless steel (SS) using electrodeposition technique for touch surface applications. Electrodeposition was performed using a non-cyanide electrolyte, with varying copper concentrations. The copper coatings were investigated for their microstructure, in vitro degradation in the simulated hand sweat environment, and antimicrobial activity in an agar medium. It is noted that all the coatings have nanostructures in their microstructure. The microstructure of the coatings along with the contact period with the bacteria affects the antimicrobial activity measured against Escherichia coli and Staphylococcus aureus. The nanostructured morphology has resulted in an increased surface area with enhanced copper toxicity. The degradation behavior of coatings in the simulated hand sweat solution was further probed using potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS). © 2022 Elsevier B.V.