Yazar "Ozturk, Ismail" seçeneğine göre listele

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    Antibacterial properties of subphthalocyanine and subphthalocyanine-TiO2 nanoparticles on Staphylococcus aureus and Escherichia coli
    (World Scientific Publ Co Pte Ltd, 2018) Ozturk, Ismail; Tuncel, Ayga; Ince, Mine; Ocakoglu, Kasim; Hosgor-Limoncu, Mine; Yurt, Fatma
    Nowadays the problem of antimicrobial resistance is the most important cause of morbidity and mortality in the treatment of infectious diseases worldwide. Treatment options for antimicrobial-resistant microorganisms are quite limited. Therefore, alternative treatment strategies are needed to control infectious diseases. Antimicrobial photodynamic therapy (aPDT) is one of the new treatment modalities proposed for a wide variety of infections. In the basic principle of aPDT, photosensitizers (PS) produce free radicals by irradiating them with harmless light at the appropriate wavelength, and this causes microorganism cell cytotoxicity. In this study, light emitting diodes (LED) (630-700 nm, 17.4 mW/cm(2)) were used on Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) at different light doses under the minimum inhibitory concentration (MIC) values of SubPc and SubPc-integrated TiO2 nanoparticles (SubPc-TiO2) concentration. Both compounds show good phototoxicity toward S. aureus when high light doses (16, 24 J/cm(2)) were applied. In addition, SubPc-TiO2 were found to be more effective than SubPc in aPDT of S. aureus. In E. coli, the success of aPDT has been shown to be dependent on the increased light dose (20, 30 J/cm(2) ) for both compounds. As a result, the aPDT activity of SubPc-TiO2 is more effective than SubPc in increasing light doses.
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    Antifungal photodynamic activities of phthalocyanine derivatives on Candida albicans
    (Elsevier, 2020) Ozturk, Ismail; Tuncel, Ayca; Yurt, Fatma; Biyiklioglu, Zekeriya; Ince, Mine; Ocakoglu, Kasim
    Antimicrobial resistance is one of the most important causes of morbidity and mortality in the treatment of infectious diseases worldwide. Candida albicans is one of the most virulent and common species of fungi to cause invasive fungal infections on humans. Alternative treatment strategies, including photodynamic therapy, are needed for controlling these infectious diseases. The aim of this study was to investigate the antifungal photodynamic activities of phthalocyanine derivatives on C. albicans. The minimum inhibitory concentration (MIC) values of compounds were determined by the broth microdilution method. Uptake of the compounds in C. albicans and dark toxicity of the compounds were also investigated. Photodynamic inhibition of growth experiments was performed by measuring the colony-forming unit/mL (CFU/mL) of the strain. Maximum uptake into the cells was observed in the presence of 64 mu g/mL concentration for each compound except for ZnPc. Compounds did not show dark toxicity/inhibitory effects at sub-MIC concentrations on C. albicans when compared to the negative control groups. Zn(II)Pc, ZnPc, and ZnPc-TiO2 showed fungicidal effect after irradiation with the light dose of 90 J/cm(2) in the presence of the compounds. In addition to the fungicidal effects, SubPc, SubPc-TiO2, Es-SiPc, and Es-SubPc compounds were also found to have inhibitory effects on the growth of yeast cells after irradiation.
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    Antimicrobial photodynamic therapy against Staphylococcus aureus using zinc phthalocyanine and zinc phthalocyanine integrated TiO2 nanoparticles
    (World Scientific Publ Co Pte Ltd, 2019) Tuncel, Ayca; Ozturk, Ismail; Ince, Mine; Ocakoglu, Kasim; Hosgor-Limoncu, Mine; Yurt, Fatma
    Antibiotic resistance is an increasing healthcare problem worldwide. In the present study, the effects of antimicrobial photodynamic therapy (APDT) of ZnPc and ZnPc-integrated TiO2 nanoparticles (ZnPc-TiO2) were investigated against Staphylococcus aureus. A light emitting diode (LED) (630-700 nm, 17.4 mW/cm(2)) was used on S. aureus at different light doses (8 J/cm(2) for 11 min, 16 J/cm(2) for 22 min, 24 J/cm(2) for 33 min) in the presence of the compounds under the minimum inhibitory concentration values. Both compounds showed similar phototoxicity toward S. aureus when high light doses (16 and 24 J/cm(2)) were applied. In addition, the success of APDT increased with an increasing light dose.
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    Development of antimicrobial nanocomposite scaffolds via loading CZTSe quantum dots for wound dressing applications
    (Iop Publishing Ltd, 2022) Ceylan, Seda; Sert, Buse; Yurt, Fatma; Tuncel, Ayca; Ozturk, Ismail; Demir, Didem; Ocakoglu, Kasim
    The antimicrobial properties of scaffolds designed for use in wound healing are accepted as an important factor in the healing process to accelerate the wound healing process without causing inflammation. For this purpose, chitosan-polyvinyl alcohol composite membranes loaded with Cu2ZnSnSe4 quantum dots (CZTSe QDs) as an antibacterial and cytocompatible biomaterial to regulate the wound healing process were produced. CZTSe QDs particles were synthesized under hydrothermal conditions. Polymer-based nanocomposites with different concentrations of the synthesized nanoparticles were produced by the solvent casting method. After detailed physicochemical and morphological characterizations of CZTSe QDs and composite membranes, antibacterial activities and cell viability were extensively investigated against gram-positive and gram-negative bacterial and yeast strains, and L929 mouse fibroblast cells lines, respectively. The results show that the preparation of composite scaffolds at a QDs concentration of 3.3% by weight has the best antimicrobial activity. Composite scaffold membranes, which can be obtained as a result of an easy production process, are thought to have great potential applications in tissue engineering as wound dressing material due to their high mechanical properties, wettability, strong antibacterial properties and non-toxicity.
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    Enhanced bacterial uptake of 131I-labeled antimicrobial imidazolium bromide salts using fluorescent carbon nanodots
    (Elsevier, 2021) Duman, Ali Niyazi; Colak, Suleyman Gokhan; Alas, Melis Ozge; Er, Ozge; Tuncel, Ayca; Ozturk, Ismail; Yurt, Fatma
    Imidazolium bromide salts have been shown as potent antibiotic molecules that show structure-based bioactivity related to their cation alkyl side chain length. To enhance the bioavailability of lipophilic alkyl side chains herein, a 1,8-naphthalimide group containing imidazolium bromide salts bearing different lengths of alkyl chains (NIM1, 2, and 3) are coupled with fluorescent carbon dots (C-NIMs) through electrostatic and pi-pi interactions. Further, obtained nanocarriers were radio-labeled with iodine-131 (I-131) to track the bacterial uptake of them by Staphylococcus aureus and Escherichia coli. Antibacterial activities were also investigated by the microdilution method. Comparison studies showed that both radiolabeling efficiency and lipophilicity increased when NIMs were integrated onto the CDots. More importantly, CDots resulted in 4-fold enhanced uptake of NIM1 by S. aureus bacterium as compared to pristine imidazolium bromide salts while at a higher number of alkyl chain lengths enhancement was 2-fold.
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    Synthesis and antimicrobial photodynamic activities of axially {4-[(1E)-3-oxo-3-(2-thienyl)prop-1-en-1-yl]phenoxy} groups substituted silicon phthalocyanine, subphthalocyanine on Gram-positive and Gram-negative bacteria
    (Elsevier Sci Ltd, 2019) Biyiklioglu, Zekeriya; Ozturk, Ismail; Arslan, Tayfun; Tuncel, Ayca; Ocakoglu, Kasim; Hosgor-Limoncu, Mine; Yurt, Fatma
    Today, the problem of antimicrobial resistance is the most important cause of morbidity and mortality in the treatment of infectious diseases worldwide. Therefore, alternative treatment strategies are important for controlling infectious diseases. In the basic principle of antimicrobial photodynamic therapy (aPDT), when harmless light at the appropriate wavelength absorbed by the photosensitizer, undergoes a transition from a ground state to a triplet state. The triplet state photosensitizer can interact with enzym and substrate molecules to produce free radicals and radical ions, or with molecular oxygen resulting in the generation of singlet oxygen which leads to cell cytotoxicity of the microorganism. For this purpose, axially {4-[(1E)-3-oxo-3-(2-thienyl) prop-1-en-1-yl] phenoxy} group substituted silicon phthalocyanine (Es-SiPc) and subphthalocyanine (Es-SubPc) were synthesized by reaction of SiPcCl2, SubPcCl with (2E)-3-(4-hydroxyphenyl)-1-(2-thienyl)prop-2-en-1-one in the presence of NaH in toluene. The new Es-SiPc and Es-SubPc were characterized by standard spectroscopy methods. The effects of aPDT in the presence of phthalocyanines were investigated against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) strains. Also, singlet oxygen generation of Es-SiPc and Es-SubPc were investigated. Our results suggest that the aPDT in the presence of newly synthesized Es-SiPc and Es-SubPc has promising antibacterial effects on Gram-positive and Gram-negative bacteria.
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    Synthesis of new water-soluble ionic liquids and their antibacterial profile against gram-positive and gram-negative bacteria
    (Elsevier Sci Ltd, 2019) Duman, Ali Niyazi; Ozturk, Ismail; Tuncel, Ayca; Ocakoglu, Kasim; Colak, Suleyman Gokhan; Hosgor-Limoncu, Mine; Yurt, Fatma
    A series of imidazolium bromide salts (NIM-Br 1a, 1b and 1c) bearing different lengths of alkyl chains were synthesized and theirin vitro antibacterial activities were determined by measuring the minimum inhibitory concentration (MIC) values for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis. In addition, these imidazolium derivatives were also evaluated against biofilm produced by these bacterial strains. All compounds were found to be effective against Gram-positive and Gram-negative bacteria, and also more effective on the S. aureus biofilm production than the others.
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    Unveiling combat strategies against Candida spp. biofilm structures: Demonstration of photodynamic inactivation with innovative phthalocyanine derivatives
    (Elsevier Science Sa, 2024) Ozturk, Ismail; Ozel, Derya; Dogan, Sifa; Tuncel, Ayca; Yurt, Fatma; Tekintas, Yamac; Demircioglu, Perihan Kubra
    Antimicrobial resistance is an important problem for infection control and therapy. Microorganisms in biofilm structure are remarkably less susceptible to antimicrobials compared to planktonic cells. Increasing rates of resistance to antimicrobials have led to the development of new antimicrobial strategies. Antimicrobial photodynamic therapy (PDT) is an alternative treatment method that may contribute to the fields of infection control and treatment. This study aimed to investigate the antifungal activities of photosensitizers and the anti -biofilm activities of phthalocyanine derivatives on C. albicans and C. parapsilosis strains. The anti -biofilm effects of aPDT on the biofilm of Candida albicans were also visualized via SEM (Scanning Electron Microscopy). Our findings showed that aPDT with phthalocyanines inhibited biofilm production levels and reduced the mature biofilm levels of Candida strains. Additionally, SEM results supported that aPDT application successfully eradicated fungal cells and inhibited the biofilm produced by C. albicans . Although more detailed experiments are needed, we suggest that the use of Pcs in aPDT may be beneficial for the treatment of biofilm-related Candida infections.