PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7645

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2011 - 20153

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Author: search.filters.author.Bulmuş, VolgaScopus Q: search.filters.scopusQuartile.Q1

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  • Article
    Citation - WoS: 22
    Citation - Scopus: 25
    The Endocytic Pathway and Therapeutic Efficiency of Doxorubicin Conjugated Cholesterol-Derived Polymers
    (Royal Society of Chemistry, 2015) Sevimli, Sema; Sagnella, Sharon; Macmillan, Alexander; Whan, Renee; Kavallaris, Maria; Bulmuş, Volga; Davis, Thomas P.
    Previously synthesized poly(methacrylic acid-co-cholesteryl methacrylate) P(MAA-co-CMA) copolymers were examined as potential drug delivery vehicles. P(MAA-co-CMA) copolymers were fluorescently labelled and imaged in SHEP and HepG2 cells. To understand their cell internalization pathway endocytic inhibition studies were conducted. It was concluded that P(MAA-co-CMA) are taken up by the cells via clathrin-independent endocytosis (CIE) (both caveolae mediated and cholesterol dependent endocytosis) mechanisms. The formation and characterization of P(MAA-co-CMA)-doxorubicin (DOX) nanocomplexes was investigated by fluorescence lifetime imaging microscopy (FLIM), UV-Visible spectroscopy (UV-Vis) and dynamic light scattering (DLS) studies. The toxicity screening between P(MAA-co-CMA)-DOX nanocomplexes (at varying w/w ratios) and free DOX, revealed nanocomplexes to exhibit higher cytotoxicity towards cancer cells in comparison to normal cells. FLIM and confocal microscopy were employed for investigating the time-dependent release of DOX in SHEP cells and the cellular uptake profile of P(MAA-co-CMA)-DOX nanocomplexes in cancer and normal cell lines, respectively. The endocytic pathway of P(MAA-co-CMA)-DOX nanocomplexes were examined in SHEP and HepG2 cells via flow cytometry revealing the complexes to be internalized through both clathrin-dependent (CDE) and CIE mechanisms. The drug delivery profile, reported herein, illuminates the specific endocytic route and therapeutic efficiency of P(MAA-co-CMA)-DOX nanocomplexes strongly suggesting these particles to be promising candidates for in vivo applications.
  • Article
    Citation - WoS: 79
    Citation - Scopus: 90
    Hydrophobically-Associating Cationic Polymers as Micro-Bubble Surface Modifiers in Dissolved Air Flotation for Cyanobacteria Cell Separation
    (Elsevier Ltd., 2014) Yap, R.K.L.; Whittaker, M.; Diao, M.; Stuetz, R. M.; Jefferson, B.; Bulmuş, Volga; Peirson, W. L.; Nguyen, A. V.; Henderson, R. K.
    Dissolved air flotation (DAF), an effective treatment method for clarifying algae/cyanobacteria-laden water, is highly dependent on coagulation-flocculation. Treatment of algae can be problematic due to unpredictable coagulant demand during blooms. To eliminate the need for coagulation-flocculation, the use of commercial polymers or surfactants to alter bubble charge in DAF has shown potential, termed the PosiDAF process. When using surfactants, poor removal was obtained but good bubble adherence was observed. Conversely, when using polymers, effective cell removal was obtained, attributed to polymer bridging, but polymers did not adhere well to the bubble surface, resulting in a cationic clarified effluent that was indicative of high polymer concentrations. In order to combine the attributes of both polymers (bridging ability) and surfactants (hydrophobicity), in this study, a commercially-available cationic polymer, poly(dimethylaminoethyl methacrylate) (polyDMAEMA), was functionalised with hydrophobic pendant groups of various carbon chain lengths to improve adherence of polymer to a bubble surface. Its performance in PosiDAF was contrasted against commercially-available poly(diallyl dimethyl ammonium chloride) (polyDADMAC). All synthesised polymers used for bubble surface modification were found to produce positively charged bubbles. When applying these cationic micro-bubbles in PosiDAF, in the absence of coagulation-flocculation, cell removals in excess of 90% were obtained, reaching a maximum of 99% cell removal and thus demonstrating process viability. Of the synthesised polymers, the polymer containing the largest hydrophobic functionality resulted in highly anionic treated effluent, suggesting stronger adherence of polymers to bubble surfaces and reduced residual polymer concentrations.
  • Article
    Citation - WoS: 46
    Citation - Scopus: 46
    Conjugation of Sirna With Comb-Type Peg Enhances Serum Stability and Gene Silencing Efficiency
    (John Wiley and Sons Inc., 2011) Gunasekaran, Karthikeyan; Nguyen, Thi H.; Maynard, Heather D.; Davis, Thomas P.; Bulmuş, Volga
    A thiol-modified siRNA targeting the enhanced green fluorescence protein (eGFP) gene was conjugated with RAFT-synthesized, pyridyl disulfide-functional poly(PEG methyl ether acrylate)s (p(PEGA)s). siRNA-p(PEGA) conjugates demonstrated significantly enhanced in vitro serum stability and nuclease resistance compared to the unmodified and thiol-modified siRNA. The complexes of siRNA-p(PEGA) conjugates with a fusogenic peptide, KALA ((+)/(-) = 2) inhibited the protein expression approximately 28-fold more than the KALA complex of the unmodified siRNA. The protein inhibition caused by siRNA-p(PEGA)-KALA complexes (56± 5%-58± 3% of the fluorescence expressed in non-treated cells) was comparable to the effect of the unmodified siRNA-lipofectamine complex (77± 7%).