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    Fabrication and Characterization of Amphotericin B Loaded Poly(Vinyl Alcohol)/Chitosan-ZnO Biocomposite Films for Antimicrobial Wound Dressings
    (Wiley, 2025) Tosyali, Ozlem Ayse; Sahin, Furkan; Cetin, Yuksel; Karal-Yilmaz, Oksan
    Developing efficient hydrogel-based wound dressings has gained increasing attention in improved wound healing capabilities. In this study, the biocomposite hydrogel films consisting of polyvinyl alcohol (PVA), chitosan (CS), and zinc oxide nanoparticles (ZnO NPs) were prepared using the solvent casting method. The biocomposite hydrogel films were also loaded (5% w/w) with Amphotericin B (AmB) as a model drug to develop a new suitable material with potential application as high-performance wound dressing with controlled drug release. The chemical nature, thermal properties, and morphology of the PVA/CS and PVA/CS-ZnO biocomposite hydrogels were analyzed and compared by FTIR, TGA, and SEM-EDX analysis. The effect of ZnO NPs on swelling behavior in the PVA/CS films was studied. PVA/CS-ZnO biocomposite hydrogels presented a lesser degree of swelling compared to ZnO-free hydrogels. The AmB-loaded hydrogel films exhibited a sustained release rate during 72 h in PBS at pH 7.4. Biocompatibility of all hydrogel types (with or without ZnO and AmB) using L929 and HaCaT cell lines was evaluated with high cell viability examined by MTT assay. The antimicrobial activity of the films was evaluated against Escherichia coli, Staphylococcus aureus, and Candida albicans using a modified AATCC 100 method, whereby the R value represents the log reduction in the number of surviving colonies. The mean R values for drug-free PVA/CS-ZnO hydrogel films were 6.81 for E. coli, 6.03 for S. aureus, and 6.82 for C. albicans. The addition of AmB further enhanced the antimicrobial activity, increasing the R values for E. coli to 7.16, for S. aureus to 6.38, and for C. albicans to 7.31, demonstrating a significant synergistic effect with maximum antimicrobial efficacy. The results showed that the AmB-loaded biocomposite hydrogel films (PVA/CS-ZnO-AmB) can be used as a new wound dressing material.
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    Nano-co-delivery of lipophosphoglycan with soluble and autoclaved leishmania antigens into PLGA nanoparticles: Evaluation of in vitro and in vivo immunostimulatory effects against visceral leishmaniasis
    (Elsevier, 2021) Tosyali, Ozlem Ayse; Allahverdiyev, Adil; Bagirova, Melahat; Abamor, Emrah Sefik; Aydogdu, Mehmet; Dinparvar, Sahar; Acar, Tayfun
    The aim of the present study was to encapsulate lipophosphoglycan molecule (LPG) which is one of the most immunogenic antigens of Leishmania parasites into PLGA nanoparticles with autoclaved or soluble leishmanial antigens, characterize synthetized nanoparticles with different methods and evaluate their in vitro/in vivo immunostimulatory activities to develop new vaccine candidates. PLGA nanoparticles including LPG and autoclaved leishmania antigen (ALA) or soluble leishmania antigen (ALA) were synthetized by double emulsion solvent evaporation method. The synthetized nanoparticles were characterized by SEM and Zeta-sizer instruments for determination of size, zeta potentials and polydispersity index (PDI) values. The antigen release profiles and encapsulation efficiencies were determined by UV-Vis spectroscopy. Griess reaction and ELISA tests were used for measurements of produced nitric oxide (NO) and cytokine levels of macrophages and splenocytes treated with nanoparticles. For determination of protective effects of nanoparticles, parasite reduction in livers and spleens of immunized mice were calculated by LDU values post-infection. According to results, (SLA-LPG) PLGA NPs and (ALA-LPG) PLGA NPs possessed the sizes of 253 and 307 nm respectively. Antigen-loaded nanoparticles elevated the released NO amounts from macrophages for 14 and 18-folds in contrast to control. Furthermore, synthetized nanoparticles significantly triggered macrophages to produce excessive levels of IFN-gamma and IL-12 cytokines. Besides it was detected that vaccination of mice with (SLA-LPG) PLGA NPs and (ALA-LPG) PLGA NPs elicited approximately 80% protection from Visceral Leishmaniasis. Furthermore, (SLA-LPG) PLGA NPs and (ALA-LPG) PLGA NPs lead to 10 to 14-folds increase in secreted Th1 cytokine levels from splenocytes than control demonstrating abundantly stimulation of T cell response following to vaccination with nano-vaccine formulations. These results reveal that both (SLA-LPG) PLGA NPs and (ALA-LPG) PLGA NPs have excellent immunostimulatory activities and they are promising nanovaccine formulations for the prevention of leishmaniasis in near future.
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    Polymeric Approach to Adjuvant System in Antibody Production against Leishmaniasis Based on Hybridoma Technology
    (Iranian Scientific Society Medical Entomology, 2022) Yildiz, Asli Pinar Zorba; Koken, Gulnaz Yildirim; Abamor, Emrah Sefik; Bagirova, Melahat; Tosyali, Ozlem Ayse; Kocagoz, Tanil; Allahverdiyev, Adil
    Background: Leishmaniasis is a zoonotic disease, which is one of the serious public health problems in the world. Nowadays, antibody production using hybridoma technology may be a correct approach in terms of sensitivity in the diagnosis of diseases such as leishmaniasis. The aim of this study was investigation of the effectiveness of different adjuvants on polyclonal antibody production against L. tropica based on hybridoma technique.Methods: Accordingly, Freund's adjuvant (1956, M. tuberculosis), as a classic adjuvant in studies, was used comparatively with the non-toxic polymeric based Polyoxidonium adjuvant. All animal immunization procedures were conducted at Bezm-i Alem University Experimental Animal Research Center. The adjuvant response was tested both in the serum sample and in the antibodies produced by the hybridomas. The antibody titers were determined with ELISA.Results: Freund's and Polyoxidonium (PO) group blood titer's increased approximately 5.5 fold compared to control after the 6(th) and 8(th) immunization. Hybridomas produced from mice immunized with PO adjuvant induced only antigen-specific antibody response and did not develop an immune response against the adjuvant.Conclusion: Adjuvant selection is very important in terms of the specificity of antibody responses of cells produced in hybridoma technology. Therefore, PO is recommended as a new adjuvant system in this study.