Yazar "Dizge, Nadir" seçeneğine göre listele
Listeleniyor 1 - 7 / 7
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Antibacterial and antioxidant activity of gold and silver nanoparticles in dextran–polyacrylamide copolymers(Springer Link, 2024) Tkachenko, Anton; Özdemir, Sadin; Tollu, Gülşah; Dizge, Nadir; Ocakoglu, Kasım; Prokopiuk, Volodymyr; Onishchenko, Anatolii; Сhumachenko, Vasyl; Virych, Pavlo; Pavlenko, Vadym; Kutsevol, NataliyaSearch for new antimicrobial agents is of great significance due to the issue of antimicrobial resistance, which nowadays has become more important than many diseases. The aim of this study was to evaluate the toxicity and biological effects of a dextran-graft-polyacrylamide (D-PAA) polymer-nanocarrier with/without silver or gold nanoparticles (AgNPs/D-PAA and AuNPs/D-PAA, respectively) to analyze their potential to replace or supplement conventional antibiotic therapy. The toxicity of nanocomplexes against eukaryotic cells was assessed on primary dermal fibroblasts using scratch, micronucleus and proliferation assays. DPPH (2,2-diphenyl-1-picrylhydrazylradical) assay was used to evaluate the antioxidant capacity of D-PAA, AgNPs/D-PAA and AuNPs/D-PAA. DNA cleavage, antimicrobial and biofilm inhibition effects of nanocomplexes were investigated. Nanocomplexes were found to be of moderate toxicity against fibroblasts with no genotoxicity observed. AgNPs/D-PAA reduced motility and proliferation at lower concentrations compared with the other studied nanomaterials. AgNPs/D-PAA and AuNPs/D-PAA showed radical scavenging capacities in a dose-dependent manner. The antimicrobial activity of AgNPs/D-PAA against various bacteria was found to be much higher compared to D-PAA and AuNPs/D-PAA, especially against E. hirae, E. faecalis and S. aureus, respectively. D-PAA, AgNPs/D-PAA and AuNPs/D-PAA showed DNA-cleaving and biofilm inhibitory activity, while AgNPs/D-PAA displayed the highest anti-biofilm activity. AgNPs/D-PAA and AuNPs/D-PAA were characterized by good antimicrobial activity. According to the findings of the study, AgNPs/D-PAA and AuNPs/D-PAA can be evaluated as alternatives for the preparation of new antimicrobial agents, the fight against biofilms, sterilization and disinfection processes. Our findings confirm the versatility of nanosystems based on dextran-polyacrylamide polymers and indicate that AgNPs/D-PAA and AuNPs/D-PAA can be evaluated as alternatives for the preparation of novel antimicrobial agents.Öğe Boron-based magnesium diboride nanosheets preparation and tested for antimicrobial properties for PES membrane(Elsevier, 2023) Küçükosman, Rıdvan; Işık, Zelal; Ocakoğlu, Kasım; Dizge, Nadir; Özdemir, SadinAntimicrobial resistance to antibiotics for current bacterial infection treatments is a medical problem. 2D nanoparticles, which can be used as both antibiotic carriers and direct antibacterial agents due to their large surface areas and direct contact with the cell membrane, are important alternatives in solving this problem. This study focuses on the effects of a new generation borophene derivative obtained from MgB2 particles on the antimicrobial activity of polyethersulfone membranes. MgB2 nanosheets were created by mechanically separating magnesium diboride (MgB2) particles into layers. The samples were microstructurally characterized using SEM, HR-TEM, and XRD methods. MgB2 nanosheets were screened for various biological activities such as antioxidant, DNA nuclease, antimicrobial, microbial cell viability inhibition, and antibiofilm activities. The antioxidant activity of nanosheets was 75.24 ± 4.15% at 200 mg/L. Plasmid DNA was entirely degraded at 125 and 250 mg/L nanosheet concentrations. MgB2 nanosheets exhibited a potential antimicrobial effect against tested strains. The cell viability inhibitory effect of the MgB2 nanosheets was 99.7 ± 5.78%, 99.89 ± 6.02%, and 100 ± 5.84% at 12.5 mg/L, 25 mg/L, and 50 mg/L, respectively. The antibiofilm activity of MgB2 nanosheets against S. aureus and P. aeruginosa was observed to be satisfactory. Furthermore, a polyethersulfone (PES) membrane was prepared by blending MgB2 nanosheets from 0.5 wt to 2.0 wt %. Pristine PES membrane also has shown the lowest steady-state fluxes at 30.1 ± 2.1 and 56.6 L/m2h for BSA and E. coli, respectively. With the increase of MgB2 nanosheets amount from 0.5 to 2.0 wt%, steady-state fluxes increased from 32.3 ± 2.5 to 42.0 ± 1.0 and from 15.6 ± 0.7 to 24.1 ± 0.8 L/m2h, respectively for BSA and E. coli. E. coli elimination performance of PES membrane coated with MgB2 nanosheets at different rates and the membrane filtration procedure was obtained from 96% to 100%. The results depicted that BSA and E. coli rejection efficiencies of MgB2 nanosheets blended PES membranes increased when compared to pristine PES membranes.Öğe The different impacts of g-C3N4 nanosheets on PVDF and PSF ultrafiltration membranes for Remazol black 5 dye rejection(Wiley, 2023) Şenol Arslan, Dilek; Gül, Ayşe; Dizge, Nadir; Ocakoğlu, Kasım; Uzal, NigmetMembranes combined with nanoparticles are an excellent combinationcapable of successfully removing various contaminants, such as dyes fromwastewater while using very little energy and decreasing pollution. The pre-sent study reports an efficient approach for Remazol Black 5 (RB5) dyeremoval using composite graphitic carbon nitride nanosheets (g-C 3 N 4 ), poly-sulfone (PSF), and polyvinylidene fluoride (PVDF) membranes. The mem-branes were prepared using the phase inversion method, with varyingquantities of g-C 3 N 4 nanosheets ranging from 0.1%, 0.2% to 0.3%. The preparedg-C3 N4 nanosheets were characterized by FTIR, SEM analyses, and zeta poten-tial measurements. FTIR and SEM studies, contact angle, water permeability,COD, and dye rejection measurements were used to characterize the g-C3 N4nanosheets embedded in PSF and PVDF membranes. After the addition of0.3 wt% g-C3 N 4 , the water flux of the 0.3 wt% g-C 3 N4 embedded PSF mem-brane was the highest, whereas the water flux of the 0.3 wt% g-C3 N4 embeddedPVDF membrane was the lowest. The ultrafiltration (UF) membrane's perfor-mance with g-C3 N4 embedded showed an RB5 rejection rate of more than 80%and a COD removal efficiency of more than 45%. The results of the experimen-tal filtration showed that RB5 rejection reached maximum values of 91.3% for0.1 wt% g-C3 N 4 /PSF, and 85.6% for 0.3 wt% g-C 3 N4 /PVDF.Öğe Immobilization of Alpha-Amylase onto Ni2+ Attached Carbon Felt: Investigation of Kinetic Parameters from Potato Wastewater(Wiley, 2023) Acet, Ömür; İnanan, Tülden; Öndül Koç, Eda; Sert, Buse; Önal Acet, Burcu; Odabaşı, Mehmet; Ocakoğlu, Kasım; Dizge, Nadirα-amylase is an important enzyme for textile, food, paper, and the pharmaceutical industrial areas. In this study, Ni2+ attached carbon felt structures with nitrogen active site (Ni2+-N-ACF) are produced. The surface morphologies of the N-ACF and Ni2+-N-ACF are investigated by means of scanning electron microscopy (SEM) analysis. Ni2+ ions binding on the N-ACFs are determined by energy dispersive X-ray (EDX) analysis and a graphite furnace atomic absorption spectrometer (AAS). The effect of pH, ionic strength, initial α-amylase concentration, and temperature parameters is investigated for α-amylase immobilization on Ni2+-N-ACF structures. In addition, pH and temperature effect on the activities of the free and the immobilized amylase, kinetic parameters, storage, and operational stabilities are made. Lastly, starch degradation in potato waste water is tested on Ni2+-N-ACF. The obtained results show that α-amylase immobilized Ni2+-N-ACF can be used for starch degradation on an industrial scale.Öğe Investigation of the treatment and antibacterial properties of pollutant-containing water using black phosphorus blended polyethersulfone membranes(Elsevier Ltd, 2024) Eskikaya, Ozan; Kucukosman, Rıdvan; Ozdemir, Sadin; Yalcin, M. Serkan; Ocakoglu, Kasım; Dizge, NadirThe most important problem of membrane processes is clogging and therefore the reduction of their useful life. In order to eliminate such problems, the production of composite membranes is an option in membrane treatment systems. In this study, the usability of black phosphorus (BP) in membrane treatment systems, and its effect on antibacterial and treatment performance were studied. BP blended PES membranes (BP@PES) produced by loading BP into the polyethersulfone (PES) membranes were used for the treatment of bovine serum albumin (BSA) and Escherichia coli (E. coli). For this purpose, BP was added at three different amounts (0.5 %, 1.0 %, and 2.0 %) into PES membranes. Membranes with different BP amounts produced were named as 0.5%BP@PES, 1.0%BP@PES, and 2.0%BP@PES. After the production of these composite membranes, they were used in the dead-end filtration system and compared with the PES membrane without BP (bare PES). The removal effectiveness of bare PES was found to be 53.40 % in the BSA rejection results, and it was discovered to be 60.90 %, 97.15 %, and 100 % for 0.5%BP@PES, 1.0%BP@PES, and 2.0%BP@PES, respectively. The antioxidant activity of BP was 70.86% at 100 mg/L. Newly prepared BP caused single-strand DNA nuclease abilities at 50, 100, and 200 mg/L. BP showed the effective antimicrobial activity. The most antimicrobial activity was determined as a minimum inhibitory concentration (MIC) value of 8 mg/L against E. hirae and 100 % E. coli viability inhibition activity was achieved at 50 and 100 mg/L after 90 min exposure. BP also inhibited the biofilm formation of P. aeruginosa at 87.19 % and S. aureus at 90.28 % at 50 mg/L. Thus, both the effect of BP on membrane performance and its antibacterial properties were investigated. Pure water fluxes, BSA and E.coli rejection performances, and antibacterial properties of all membranes used in the membrane filtration system were investigated in detail. It is recommended to further investigate BP-containing membranes with different production techniques.Öğe The Syntheses of Chromium Aluminum Carbide (Cr2AlC) MAX Phase and Cr2CTx MXene and Investigation of Their Antimicrobial Properties(Springer, 2024) Kaya, Gül; Koç, Eda Ondul; Özdemir, Sadin; Yalçın, M. Serkan; Ocakoğlu, Kasım; Dizge, NadirChromium aluminum carbide (Cr2AlC) MAX phase and Cr2CTx (MXene-Cr) were synthesized by the pressureless sintering method and hydrothermal method, respectively. In addition to this, the free radical scavenging activities (FRSA) of MAX-Cr phase and MXene-Cr compounds were tested and compared with ascorbic acid and trolox as standard compounds. The obtained FRSA results of MAX-Cr phase and MXene-Cr were 42.82 and 59.64%, respectively, at 100 mg/L concentration. MXene-Cr showed a 66.90% inhibitory effect on α-amylase at 200 mg/L. The DNA nuclease activity of compounds was determined to be extremely satisfactory at 50, 100, and 200 mg/L concentrations. Moreover, the prepared MAX-Cr phase and MXene-Cr were investigated for antimicrobial activity against six bacterial and two fungal strains by the broth microdilution method. Compounds provided more significant inhibition against Gram-positive bacteria than Gram-negative bacteria and fungi. MAX-Cr phase and MXene-Cr almost completely inhibited microbial cell viability at a 25 mg/L concentration. Additionally, MXene-Cr showed 89.86% and 87.01% antibiofilm activity against S. aureus and P. aeruginosa, respectively, while the antibiofilm activity of the MAX-Cr phase was over 90%.Öğe Synthesis of PES membranes modified with polyurethane–paraffin wax nanocapsules and performance of bovine serum albumin and humic acid rejection(IWA Publishing, 2023) Sert, Buse; Kaya, Gul; Ozay, Yasin; Alterkaoui, Aya; Ocakoglu, Kasım; Dizge, NadirMembrane fouling is a serious handicap of membrane-based separation, as it reduces permeation flux and hence increases operational and maintenance expenses. Polyurethane–paraffin wax (PU/PW) nanocapsules were integrated into the polyethersulfone membrane to manufacture a composite membrane with higher antifouling and permeability performance against humic acid (HA) and bovine serum albumin (BSA) foulants. All manufactured membranes were characterized by scanning electron microscopy (SEM), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), and contact angle. The contact angle of the pristine polyethersulfone (PES) membrane was measured 73.40 + 1.32. With the embedding of nanocapsules, the contact angle decreased to 64.55 + 1.23 for PES/PU/PW 2.0 wt%, and the pure water flux of all composite membranes increased when compared to pristine PES. The pristine PES membrane also has shown the lowest steady-state fluxes at 45.84 and 46.59 L/m2 h for BSA and HA, respectively. With the increase of PU/PW nanocapsule ratio from 0.5 to 1.0 wt%, steady-state fluxes increased from 51.96 to 71.61 and from 67.87 to 98.73 L/m2 h, respectively, for BSA and HA. The results depicted that BSA and HA rejection efficiencies of PU/PW nanocapsules blended PES membranes increased when compared to pristine PES membranes
