Person: TINAZ, GÜLGÜN
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TINAZ
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GÜLGÜN
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Publication Metadata only Fabrication and characterization of electrospun GelMA/PCL/CS nanofiber composites for wound dressing applications(2022-12-01) TINAZ, GÜLGÜN; GÜNDÜZ, OĞUZHAN; Pilavci E., Ayran M., Ulubay D., Kaya E., TINAZ G., Ozakpinar O. B., Sancakli A., GÜNDÜZ O.In the present study, the effect of different ratios of GelMA concentration has been exhibited for wound dressing implementation by the electrospinning method using a new polymer combination of Gelatin methacrylate (GelMA)/Polycaprolactone (PCL)/Chitosan (CS). The nanofiber composites were fabricated due to their biocompatible, biodegradable, improved mechanical strength, low degradation rate, and hydrophilic nature to develop cell-mimicking, cell adhesion, proliferation, and differentiation. Different concentrations of GelMA were added to the PCL/CS solution as 5, 10, and 20 wt%, respectively, in the formic acid/acetic acid (7:3) solution. A photoinitiator was added to the solution for photo-crosslinking of GelMA. The influence of different solution concentrations (5, 10, and 20 wt%) on the structure\"s nanofiber production and fiber morphology was examined. SEM micrographs revealed that varied GelMA concentrations resulted in suitable and stable nanofiber composites. The average diameter of nanofiber composites grows as the GelMA concentration rises. FTIR, DSC, tensile test, degradation, and swelling test were evaluated. The results demonstrated that high mechanical strength, hydrophilic properties, and a slow degradation rate were observed with the presence and increment of GelMA concentration within the nanofiber composites. The antibacterial potential of GelMA/PCL/CS nanofiber composites was evaluated against P. aeruginosa and S. aureus using a disc diffusion assay. In vitro cell culture research was conducted by seeding NIH 3T3 fibroblast cells on nanofiber composites, proving these cells\" high cell proliferation rate, viability, and adhesion. 10 wt% GelMA-based nanofiber composites were found to have great potential for wound dressing applications.Publication Metadata only Quorum Sensing Inhibitor Activities of Celecoxib Derivatives in Pseudomonas aeruginosa(BENTHAM SCIENCE PUBL LTD, 2017) TINAZ, GÜLGÜN; Ulusoy, Seyhan; Senkardes, Sevil; Coskun, Inci; Bosgelmez-Tinaz, Gulgun; Soulere, Laurent; Queneau, Yves; Kucukguzel, S. GunizBackground: A series of novel N-(substituted aryl/alkylcarbamothioyl)-4-[5-(4-methylphenyl)3-( trifluoromethyl)-1H-pyrazol-1-yl] benzene sulfonamides [SGK 318, 319, 320, 324, 327] and N-(3-substitutedaryl/ alkyl-4-oxo-1,3-thiazolidin-2-ylidene)-4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl] benzenesulfonamides[SGK 328, 329, 330, 334, 337] were synthesized and tested for their quorum sensing inhibitor (QSI) capacity using quorum sensing inhibitor selector 1 (QSIS1) bioassay. Findings: QSIS assay revealed that SGK 324, SGK 327 and SGK 330 have the potentials to interfere with QS system in QS inhibitor selector1 (QSIS1) reporter strain. Moreover, these compounds were found to significantly affect QS regulated elastase and biofilm productions in Pseudomonas aeruginosa PA01 strain without affecting its growth. Molecular modeling experiments suggested that SGK 330 fits within the binding site of LasR protein of P. aeruginosa. SGK 324 and 327 also bind LasR provided that they adopt a s-trans/s-cis conformation with respect to the thiourea function. Results and Conclusion: Results of this study indicated that these compounds could be developed as new QS inhibitors without killing the bacteria but as antivirulence compounds to restrict virulence of clinically important human pathogens.Publication Open Access Phenolic compounds affect production of pyocyanin, swarming motility and biofilm formation of Pseudomonas aeruginosa(WOLTERS KLUWER MEDKNOW PUBLICATIONS, 2016-08) KARAHASAN, AYŞEGÜL; Ugurlu, Aylin; Yagci, Aysegul Karahasan; Ulusoy, Seyhan; Aksu, Burak; Bosgelmez-Tinaz, GulgunObjective: To investigate the effects of plant-derived phenolic compounds (i.e. caffeic acid, cinnamic acid, ferulic acid and vanillic acid) on the production of quorum sensing regulated virulence factors such as pyocyanin, biofilm formation and swarming motility of Pseudomonas aeruginosa (P. aeruginosa) isolates. Methods: Fourteen clinical P. aeruginosa isolates obtained from urine samples and P. aeruginosa PA01 strain were included in the study. The antibacterial effects of phenolic compounds were screened by well diffusion assay. Pyocyanin and biofilm activity were measured from culture supernatants and the absorbance values were measured using a spectrophotometer. Swarming plates supplemented with phenolic acids were point inoculated with P. aeruginosa strains and the ability to swarm was determined by measuring the distance of swarming from the central inoculation site. Results: Tested phenolic compounds reduced the production of pyocyanin and biofilm formation without affecting growth compared to untreated cultures. Moreover, these compounds blocked about 50% of biofilm production and swarming motility in P. aeruginosa isolates. Conclusions: We may suggest that if swarming and consecutive biofilm formation could be inhibited by the natural products as shown in our study, the bacteria could not attach to the surfaces and produce chronic infections. Antimicrobials and natural products could be combined and the dosage of antimicrobials could be reduced to overcome antimicrobial resistance and drug side effects.Publication Metadata only Investigation of Antimicrobial and Biofilm Properties of 3D Alginate/PolyethyleneGlycol/Phenethyl Alcohol Scaffolds.(2022-11-26) ULAĞ, SONGÜL; GÜNDÜZ, OĞUZHAN; TINAZ, GÜLGÜN; Aslan S. N., Altan E., ULAĞ S., GÜNDÜZ O., TINAZ G.Publication Open Access The Role of Multilayer Electrospun Poly(Vinyl Alcohol)/Gelatin nanofibers loaded with Fluconazole and Cinnamaldehyde in the Potential Treatment of Fungal Keratitis(2022-08-01) GÜNDÜZ, OĞUZHAN; TINAZ, GÜLGÜN; ŞENGÖR, MUSTAFA; CESUR, SÜMEYYE; Ilhan E., Cesur S., Sulutas R. B., Pilavci E., Dalbayrak B., Kaya E., Arisan E. D., Tinaz G., ŞENGÖR M., Kijeenska-Gawaronska E., et al.Fungal keratitis is a severe corneal infection that causes irreversible damage to the cornea, for which conventional drug treatments may be insufficient. With the new generation of drug delivery systems, it is desired to ensure the ocular usability of drugs. In this study, two-layer polyvinyl alcohol and gelatin (PVA/GEL) nanofibers with high drug loading capacity were produced by the electrospinning method. Cinnamaldehyde (CA), an FDAapproved volatile molecule found in cinnamon essential oil, and fluconazole (FLU), an antifungal drug, were incorporated into PVA/GEL nanofibers to inhibit the growth and biofilm formation of Candida albicans, one of the pathogens that cause fungal keratitis. The morphology, chemical structures, and thermal transitions of the produced pure (PVA/GEL), FLU loaded (PVA/GEL/FLU), CA loaded (PVA/GEL/CA), and combined FLU and CA loaded (PVA/GEL/COM) nanofibers were analysed by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC), respectively. The mechanical analysis, swelling and degradation behaviour, and drug release kinetics of the nanofibers were investigated. PVA/ GEL/FLU, PVA/GEL/CA and PVA/GEL/FLU/COM nanofibers were evaluated for their antifungal and antibiofilm activity against Candida albicans. Results showed that PVA/GEL/FLU and PVA/GEL/COM nanofibers have significant antifungal activity and inhibited biofilm formation by 37% and 49%, respectively. Furthermore, it was determined by MTT analysis using a human embryonic kidney (HEK) that the nanofibers were not cytotoxic. In the treatment of fungal keratitis, double-layer PVA/GEL/COM nanofiber with CA in the first layer and FLU in the second layer can create a new treatment approach as an alternative drug delivery system.Publication Metadata only Study on potential of additive manufactured wound dressing from hemp seed oil/polycaprolactone(2022-11-06) UZUN, MUHAMMET; ALTAN, ERAY; TINAZ, GÜLGÜN; GÜNDÜZ, OĞUZHAN; Ertaş İ. F., UZUN M., ALTAN E., Kabir M. H., TINAZ G., GÜNDÜZ O.Publication Metadata only Multilayer patches for the treatment of corneal perforations caused by infections(2022-09-28) CESUR, SÜMEYYE; TINAZ, GÜLGÜN; ŞENGÖR, MUSTAFA; OKTAR, FAİK NÜZHET; GÜNDÜZ, OĞUZHAN; Kijeńska-Gawrońska ., İlhan E., Cesur S., Sulutaş R. B., Pilavcı E., Dalbayrak B., Kaya E., Arısan E. D., Tınaz G., Şengör M., et al.Publication Metadata only Zeolite 4A as a jammer of bacterial communication in chromobacterium violaceum and pseudomonas aeruginosa(2022-07-01) TINAZ, GÜLGÜN; ULUSOY S., B Akalin R., cevikbas H., Berisha A., ORAL A., TINAZ G.Aim: To investigate the hypothesis that zeolites interfere with quorum-sensing (QS) systems of Chromobacterium violaceum and Pseudomonas aeruginosa by adsorbing N-acyl homoserine lactone (AHL) signal molecules. Methods: QS inhibition by zeolite 4A was investigated using an AHL-based bioreporter assay. The adsorption of the AHLs was evaluated by performing inductively coupled plasma-optical emission spectroscopy and confirmed by Monte Carlo and molecular dynamic simulations. Results: Zeolite 4A reduced the violacein production in C. violaceum by over 90% and the biofilm formation, elastase and pyocyanin production in P. aeruginosa by 87, 68 and 98%, respectively. Conclusion: Zeolite 4A disrupts the QS systems of C. violaceum and P. aeruginosa by means of adsorbing 3-oxo-C6-AHL and 3-oxo-C12-AHL signaling molecules and can be developed as a novel QS jammer to combat P. aeruginosa-related infections.Publication Metadata only Synthesis and Biological Activities of Some 1,3-Benzoxazol-2(3H)-One Derivatives as Anti-Quorum Sensing Agents(GEORG THIEME VERLAG KG, 2012) TINAZ, GÜLGÜN; Miandji, A. M.; Ulusoy, S.; Dundar, Y.; Ozgen, S.; Onurdag, F. K.; Bosgelmez-Tinaz, G.; Noyanalpan, N.Antibiotics are commonly used to treat microbial infections. Due to misuse or large-scale use of antibiotics, many pathogens have gained resistance which makes antibiotic treatments ineffective. The discovery that many bacteria use quorum sensing (QS) to regulate their virulence factor and pathogenicity production makes the QS system an attractive target for antimicrobial therapy. A series of 1,3-benzoxazol-2(3H)-one derivatives were designed and synthesized as QS inhibitors (QSIs) and tested for their QS inhibitory activities. In vitro quorum sensing inhibitor screen (QSIS) assay indicated that the 1,3-benzoxazol-2(3H)-one (compound 1), 5-chloro-1,3-benzoxazol-2(3H)-one (compound 6), 6-methyl-1,3-benzoxazol-2(3H)-one (compound 11), and 5-methyl-1,3-benzoxazol-2(3H)-one (compound 16), inhibit QS system in quorum sensing selector (QSIS)1 strain. These 4 QSIs also significantly reduced elastase production, biofilm formation and swarming motility of Pseudomonas aeruginosa PA01 strain. These results suggest that compound 1, 6, 11 and 16 may provide a starting point for the design and development of new anti-pathogenic drugs that restrict virulence of P. aeruginosa and possibly other clinically important human pathogens. In addition, these QSI molecules could potentially be used in combination with conventional antibiotics to increase the efficiency of disease control and to extend the life span of established antimicrobials.Publication Open Access A novel strategy as a potential rapid therapy modality in the treatment of corneal ulcers: Fluconazole/vancomycin dual drug-loaded nanofibrous patches(2023-01-01) CESUR, SÜMEYYE; BİNGÖL ÖZAKPINAR, ÖZLEM; TINAZ, GÜLGÜN; OKTAR, FAİK NÜZHET; GÜNDÜZ, OĞUZHAN; CESUR S., Ilhan E., Pilavci E., Sulutas R. B., Gurboga M., BİNGÖL ÖZAKPINAR Ö., Kaya E., Heljak M., TINAZ G., OKTAR F. N., et al.Corneal ulcer, which is brought on by a breach in the epithelial barrier, is a dangerous infection of the avascular corneal stroma. New treatment strategies are needed, suppressing the aggressive nature of the disease and including a combination of different drugs. In this study, vancomycin (VAN) and fluconazole (FLU) dual-drug loaded dual-layered polyvinyl alcohol and gelatin (PVA/GEL) nanofibrous patches are produced by electrospinning. Scanning electron microscopy (SEM) images show smooth surfaces are obtained for both pure and drug-loaded nanofibrous patches. The tensile test results report that loading the FLU and VAN separately into the PVA/GEL patches decrease both the tensile strength and elongation at break and it is further reduced when combining two drug-loaded layers in one patch. According to drug release results, the FLU and VAN-loaded nanofibrous patches show a controlled release profile extending up to 96 h. Moreover, PVA/GEL/FLU, PVA/GEL/VAN, and PVA/GEL/FLU/VAN nanofibrous patches display significant antimicrobial activity against Candida albicans and Staphylococcus aureus. SEM, 4\"-6diamidynofenyloindol (DAPI) staining, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay show that PVA/FLU and PVA/GEL/FLU/VAN nanofibrous patches have a superior effect on NIH3T3 cell spreading and proliferation. The novelty of this study lays in the development of a potential dual drug rapid treatment for corneal ulcers of aggressive nature.