34 results on '"GÜrsel İ"'
Search Results
2. Metrics for minimising environmental impacts while maximising circularity in biobased products: The case of lignin-based asphalt
- Author
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Biobased Economy, Energy and Resources, Corona, B., Hoefnagels, R., Gürsel, I. Vural, Moretti, C., Veen, M. van, Junginger, M., Biobased Economy, Energy and Resources, Corona, B., Hoefnagels, R., Gürsel, I. Vural, Moretti, C., Veen, M. van, and Junginger, M.
- Published
- 2022
3. Investigation and Quantification of Phthalate Esters in Packaged Milk: A Study in Türkiye
- Author
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Gürsel İşçi
- Subjects
dispersive solid-phase extraction ,milk ,migration ,phthalate esters ,Agriculture ,Agriculture (General) ,S1-972 - Abstract
The aim of this study was to explore the concentrations of PAEs (Phthalate esters) in milk in Türkiye. For this purpose, a methodology was developed to quantify eight different PAEs in milk samples using a combination of dispersive solid-phase extraction (dSPE) and Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). Employing this methodology, the concentrations of PAEs were evaluated in 34 milk samples. Results indicated the presence of PAEs in the milk samples; however, all tested compounds remained within the specific migration limits established by the EU. Among the analyzed PAEs, BBP (Benzyl butyl phthalate) was not detected in any samples, while DMP (di-methyl phthalate) (ND-5.51 µg/L) and DBP (di-butyl phthalate) (ND-7.91 µg/L) exhibited the lowest concentrations. DEHP (bis(2-ethylhexyl)) was identified as the most prevalent plasticizer with a maximum concentration of 41.31 µg/L. In conclusion, this study successfully investigated PAE concentrations in Turkish milk samples using a developed methodology. The results indicated the presence of PAEs within EU-established limits, with DEHP being the predominant plasticizer. Further research and monitoring efforts are crucial to ensure ongoing safety in packaged milk products.
- Published
- 2024
- Full Text
- View/download PDF
4. EU Biorefinery Outlook to 2030 (Lot 3) : Studies on support to research and innovation policy in the area of bio-based products and services
- Author
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Platt, Richard, Bauen, Ausilio, Reumerman, Patrick, Geier, Cecile, van Ree, R., Vural Gürsel, I., Garcia Chavez, L.Y., Behrens, Martin, von Bothmer, Philip, Howes, Jo, Panchaksharam, Yamini, Vikla, Kaisa, Sartorius, Valerie, and Annevelink, E.
- Subjects
Life Science ,BBP Biorefinery & Sustainable Value Chains - Abstract
This study presents scenarios on how demand and supply for biobased chemicals and materials could grow to 2030, and provides roadmaps with actions required to increase the deployment of chemical and material driven biorefineries in the EU. The study also presents the key elements of the analysis which have supported the preparation of the scenarios and roadmaps. This includes a biorefinery classification system, a database of operational or announced biorefineries (developed in collaboration with the Joint Research Centre) for the EU and 10 non-EU countries, a detailed opportunities and barriers analysis and a market outlook to 2030 with a focus on eleven biorefinery pathways. The study was developed by E4tech (lead), BTG, Wageningen Research, FNR and ICONS with the support of over 100 stakeholders from the bio-based industry, the chemicals and materials industries, academia & research institutions, the investment community and policy makers through active participation in stakeholder workshops, meetings and interviews.
- Published
- 2021
5. Comparative cradle-to-grave life cycle assessment of bio-based and petrochemical PET bottles
- Author
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Vural Gürsel, I., Moretti, Christian, Hamelin, L., Geest Jakobsen, Line, Magnea Steingrimsdottir, Maria, Junginger, Martin, Hoibye, Linda, Shen, L., Vural Gürsel, I., Moretti, Christian, Hamelin, L., Geest Jakobsen, Line, Magnea Steingrimsdottir, Maria, Junginger, Martin, Hoibye, Linda, and Shen, L.
- Abstract
This article presents a life cycle assessment of bio-based polyethylene terephthalate (PET) bottles with a cradle to grave scope and provides a comparison with petrochemical PET bottles for 13 environmental impact categories. Besides the baseline bio-based PET bottles, which are produced from Brazilian sugarcane reflecting status-quo, two alternative hypothetical bio-based product systems were considered: European wheat straw and European crops market mix composed of maize, wheat and sugar beet. The land-use change (LUC) impacts were assessed based on a deterministic model. The end-of-life impact was assessed using the EASETECH model. Baseline bio-based PET bottles performed overall worse than conventional petrochemical PET bottles, offering only better performance (about 10%) in abiotic depletion (fossil fuels). Comparable performance is observed for climate change (2% difference without the LUC, and 7% with LUC impacts). Using European crops for ethanol production (alternative 1) instead of Brazilian sugarcane resulted in a worse environmental performance, due to lower yields attained compared to Brazilian sugarcane. When wheat straw was considered as biomass feedstock for ethanol production (alternative 2), similar environmental performance with petrochemical PET bottles was seen.
- Published
- 2021
6. Transference of Solutes Across Microcapsule Membranes
- Author
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Gürsel, İ., Hasirci, V. N., Vardar-Sukan, Fazilet, editor, and Sukan, Ş. Suha, editor
- Published
- 1992
- Full Text
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7. MAB2.0 project: Integrating algae production into wastewater treatment
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Nagy, B.J., Mako, Magdolna, Erdelyi, Istvan, Abiusi, Fabian, Reith, J.H., van den Broek, L.A.M., Vural Gürsel, I., Nagy, B.J., Mako, Magdolna, Erdelyi, Istvan, Abiusi, Fabian, Reith, J.H., van den Broek, L.A.M., and Vural Gürsel, I.
- Abstract
Different species of microalgae are highly efficient in removing nutrients from wastewater streams and are able to grow using flue gas as a CO2 source. These features indicate that application of microalgae has a promising outlook in wastewater treatment. However, practical aspects and process of integration of algae cultivation into an existing wastewater treatment line have not been investigated. The Climate-KIC co-funded Microalgae Biorefinery 2.0 project developed and demonstrated this integration process through a case study. The purpose of this paper is to introduce this process by phases and protocols, as well as report on the challenges and bottlenecks identified in the case study. These standardized technical protocols detailed in the paper help to assess different aspects of integration including biological aspects such as strain selection, as well as economic and environmental impacts. This process is necessary to guide wastewater treatment plants through the integration of algae cultivation, as unfavourable parameters of the different wastewater related feedstock streams need specific attention and management. In order to obtain compelling designs, more emphasis needs to be put on the engineering aspects of integration. Well-designed integration can lead to operational cost saving and proper feedstock treatment enabling algae growth.
- Published
- 2018
8. Involvement of sting-activating cyclic Di-nucleotides on T-cell differentiation and function: an unresolved issue
- Author
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Yıldız, B. and Gürsel, İ.
- Subjects
Adjuvan ,cGAMP ,İmmün cevap ,Immune response ,T lenfositleri ,eye diseases ,Adjuvant ,T-lymphocytes ,STING - Abstract
STING is the pivotal mediator for the recognition of host and pathogenic cytosolic dsDNA as well as cyclic di-nucleotide metabolites from microbes. Studies demonstrated that DNA released from cancerous cells are internalized by innate immune cells such as macrophages and dendritic cells in tumor microenvironment and trigger the production of interferon beta and other pro-inflammatory cytokines including interleukin 6, tumor necrosis factor alpha, and interleukin 12 through STING triggered signaling pathway. Later, these cytokines increase the cytotoxic activity of CD8+ T-cells by increasing the production of interferon gamma. This review discusses the importance of the involvement of STING during the establishment of immunity against intracellular pathogens and its direct effect on T-cells. © 2016 Turkish Journal of Immunology. All rights reserved. STING (Stimulator of interferon genes), hem patojen ve konağın kendi sitozolik çift sarmallı DNA (dsDNA)’sına hem de mikrop kaynaklı siklik di-nükleotidlerin tanınmasında önemli bir mediyatördür. Çalışmalar, kanser hücrelerinden salınan DNA’nın, makrofaj ve dendritik hücreler gibi doğal bağışıklık sistemi hücreleri tarafından tümör mikro çevresindeki hücrelerce alındığını göstermiştir. Bu internalizasyon STING’in tetiklediği yolak üzerinden interferon beta, interlökin 6, tümör nekroz faktör alfa ve interlökin 12 gibi diğer pro-enflamatuar sitokinlerin salımını yönlendirir. Daha sonra bu sitokinler interferon gama üretimini artırarak CD8+ T hücrelerinin sitotoksik etkinliklerini artırır. Bu derleme STING yolağının hücre içi patojenlere karşı oluşan immünitedeki rolünü ve T-hücreleri üzerine olası doğrudan etkilerini tartışmaktadır.
- Published
- 2016
9. Segmented flow in micro- and mini-coiled flow inverters for continuous extraction: extraction efficiency, metal (catalyst) recovery and kilo-lab upscaling
- Author
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Hessel, V., Vural - Gürsel, I., Kurt, S.K., Wang, Q., Noël, T., Nigam, K.D.P., Kockmann, N., and Micro Flow Chemistry and Synthetic Meth.
- Published
- 2016
10. Chitosan polysaccharide suppress toll like receptor dependent immune response
- Author
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Tincer G., Bayyurt, B., Arıca, Y.M., and Gürsel İ.
- Subjects
gamma interferon inducible protein 10 ,interleukin 1beta ,macromolecular substances ,animal cell ,immunomodulation ,Toll like receptor ,Article ,protein induction ,toll like receptor 6 ,toll like receptor 3 ,toll like receptor 4 ,inflammasome ,nitric oxide ,toll like receptor 1 ,toll like receptor 2 ,macrophage inflammatory protein 3alpha ,controlled study ,Polysaccharide ,protein expression ,mouse ,Innate immunity ,CXCL16 chemokine ,Chitosan ,tumor necrosis factor alpha ,nonhuman ,technology, industry, and agriculture ,equipment and supplies ,toll like receptor 9 ,Biomaterial ,Double-stranded ribonucleic acid ,alpha interferon ,toll like receptor 7 ,cryopyrin ,polyinosinic polycytidylic acid ,carbohydrates (lipids) ,cell proliferation ,cytokine release ,gene expression ,cytokine production ,cytotoxicity ,down regulation - Abstract
Objectives: Chitosan is a widely used vaccine or anti-cancer delivery vehicle. In this study, we investigated the immunomodulatory effect of chitosan/pIC nanocomplexes on mouse immune cells. Materials and methods: Proliferative and cytotoxic features of chitosan were tested via CCK-8 assay on RAW 264. 7. IL-1β production was assessed via ELISA from PEC supernatants. TNF-α, and NO induction from chitosan treated RAW cells detected by ELISA and Griess assay, respectively. mRNA message levels of TLRs and cytokines on macrophages in response to chitosan/pIC nanocomplex treatments were evaluated by RT-PCR. Results: Results revealed that chitosan is non-toxic to cells, however, proliferative capacities of macrophages were reduced by chitosan administration. Mouse PECs treated with chitosan, led to NLRP3 dependent inflammasome activation as evidenced by dose-dependent IL-1β secretion. Chitosan/pIC nanocomplexes did not improve immunostimulatory action of pIC on RAW cells, since TNF-α and NO productions remained unaltered. Expression levels of several TLRs, CXCL-16 and IFN-α messages from mouse splenocytes were down regulated in response to chitosan/pIC nanocomplex treatment. Conclusion: Our results revealed that chitosan is an anti-proliferative and inflammasome triggering macromolecule on immune cells. Utilization of chitosan as a carrier system is of concern for immunotherapeutic applications. © 2015 Turkish Journal of Immunology.
- Published
- 2015
11. Milli-scale continuous extraction with coiled flow inverter connected to phase separator
- Author
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Vural - Gürsel, I., Wang, Q., Noël, T., Hessel, V., Nigam, K.D.P., and Micro Flow Chemistry and Synthetic Meth.
- Published
- 2015
12. Potential Analysis of Smart Flow Processing and Micro Process Technology for Fastening Process Development: Use of Chemistry and Process Design as Intensification Fields
- Author
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Hessel, V., primary, Vural Gürsel, I., additional, Wang, Q., additional, Noël, T., additional, and Lang, J., additional
- Published
- 2012
- Full Text
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13. Biodegradable polyhydroxyalkanoate implants for osteomyelitis therapy: in vitro antibiotic release
- Author
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Türesin, F., primary, Gürsel, I˙., additional, and Hasirci, V., additional
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- 2001
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14. MAB2.0 project: Integrating algae production into wastewater treatment
- Author
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Nagy Balázs József, Makó Magdolna, Erdélyi István, Ramirez Andrea, Moncada Jonathan, Gursel Iris Vural, Ruiz-Martínez Ana, Seco Aurora, Ferrer José, Abiusi Fabian, Reith Hans, Broek Lambertus A.M. van den, Seira Jordan, Garcia-Bernet Diana, Steyer Jean-Philippe, and Gyalai-Korpos Miklós
- Subjects
wastewater treatment ,microalgae ,bioresource ,Biotechnology ,TP248.13-248.65 - Abstract
Different species of microalgae are highly efficient in removing nutrients from wastewater streams and are able to grow using flue gas as a CO2 source. These features indicate that application of microalgae has a promising outlook in wastewater treatment. However, practical aspects and process of integration of algae cultivation into an existing wastewater treatment line have not been investigated. The Climate-KIC co-funded Microalgae Biorefinery 2.0 project developed and demonstrated this integration process through a case study. The purpose of this paper is to introduce this process by phases and protocols, as well as report on the challenges and bottlenecks identified in the case study. These standardized technical protocols detailed in the paper help to assess different aspects of integration including biological aspects such as strain selection, as well as economic and environmental impacts. This process is necessary to guide wastewater treatment plants through the integration of algae cultivation, as unfavourable parameters of the different wastewater related feedstock streams need specific attention and management. In order to obtain compelling designs, more emphasis needs to be put on the engineering aspects of integration. Well-designed integration can lead to operational cost saving and proper feedstock treatment enabling algae growth.
- Published
- 2018
- Full Text
- View/download PDF
15. Properties and drug release behaviour of poly(3-hydroxybutyric acid) and various poly(3-hydroxybutyrate-hydroxyvalerate) copolymer microcapsules
- Author
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Gürsel, I., primary and Hasirci, V., additional
- Published
- 1995
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16. Window of opportunity – potential of increase in profitability using modular compact plants and micro-reactor based flow processing
- Author
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Gürsel Iris Vural, Hessel Volker, Wang Qi, Noël Timothy, and Lang Jürgen
- Subjects
micro process technology ,modular plants ,net present value ,Chemistry ,QD1-999 - Abstract
Recently, much focus has been given to a new type of chemical production plant, with the aim of a much faster time-to-market (“50% idea”) and better cash-flow revenue. The main enabling technology is to have the plants pre-manufactured and assembled by a modular construction and to use innovative, smart-scale processing and apparatus technology, in order to achieve a compact overall plant footprint. Focal points in such technology are on the one hand, flow processing, with micro process technology as a cutting-edge cornerstone, and on the other hand, the container framework. Yet, other process-intensified technologies are suitable as well such as milli-flow or upgraded batch technologies. Finally, process robustness and short-time applicability make the decision. In this paper, for the first time, a CAPEX and OPEX analysis of the new plant technology is done, at the example of the Evotrainer production platform. This platform is pre-manufactured in serial and provides all the utilities needed around the reactor and e.g., separator to be tailored and inserted. The unit-operational modularization, with respective definition of interfaces, was developed further to a so-called functional modularization, where different cabinets with pre-defined functions and equipment are proposed. Three virtual microreactor applications were used and stand as model-based scenarios for market applications in bulk chemistry, fine chemistry and pharmacy. It is shown, in many facets, that the Evotrainer infrastructure based plants indeed have a faster payback and higher earnings as compared to conventional technology, particularly when serving high-priced markets such as pharmaceutical applications. Further, the combination with novel chemical routes or novel processing (Novel Process Windows) is advantageous. Micro process technology is one of the key enablers and was taken here, since the dataset of such technology was readily available to the authors due to past research efforts and there is some general belief in the combination to the so-called “Future Factories”. Yet, it stands also for any other process intensification technology which can achieve the same performance level and which is able to satisfy the needs of a producing industry.
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- 2012
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17. Continuous metal scavenging in flow coupled to one-pot click reaction
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Gürsel, I. V., Aldiansyah, F., Wang, Q., Noel, T., Volker Hessel, and Micro Flow Chemistry and Synthetic Meth.
18. Improving profitability through green manufacturing: creating a profitable and environmentally compliant manufacturing facility
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Gürsel Iris Vural
- Subjects
Chemistry ,QD1-999 - Published
- 2013
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19. Downstream processing in biotechnology
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Gürsel Iris Vural
- Subjects
Chemistry ,QD1-999 - Published
- 2013
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20. Matrix entrapment of glucose oxidase by γ irradiation
- Author
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Gürsel, I. and Hasirci, V.N.
- Published
- 1992
- Full Text
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21. The effect of exosomes released from apheresis platelet concentrates under the impact of gamma irradiation and storage time upon platelet aggregation and hemostasis.
- Author
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Bal SH, Sağdilek E, Karaçay M, Kızmaz MA, Kumaş LT, Can FE, Yıldırım M, Canavar-Yıldırım T, Koşay-Gülkaya D, Yöyen-Ermiş D, Budak F, Heper Y, Gürsel İ, and Oral HB
- Subjects
- Humans, Platelet Aggregation, Blood Platelets radiation effects, Hemostasis, Blood Preservation, Exosomes, Blood Component Removal
- Abstract
Background: Blood components should be gamma-irradiated (γ-IR) in order to prevent transfusion-associated graft-versus-host disease. The aim of this study is to determine the effect of γ-IR and storage time on the exosomes released from apheresis platelet concentrates (aPC) and to investigate their impact on the maximum platelet aggregation (MPA) and hemostasis., Materials and Methods: Eight units of aPC were included in this study. These were divided into four equal portions. Two portions were irradiated before storage while the other two were not. Thus, irradiated and non-irradiated aPC samples for storage Days 0 (D0) and 5 (D5) were obtained. Exosomes were isolated from these samples using a commercial kit and were evaluated to ascertain their parent cells by flow cytometry. For the following steps, exosomes were pooled according to their features. Pooled exosomes were then used for aggregometry and thromboelastography., Results: Platelet-derived exosome (PD-EX) levels decreased in D5 compared to D0 in NI-aPC, whereas granulocyte-derived exosome (GD-EX) levels increased. Exosome pools had no effect on MPA compared to saline groups. Exosome pools decreased the time to initial fibrin formation (R), whereas they increased the rate of clot formation (α-angle) and coagulation index (CI) compared to saline groups., Discussion: Storage time and γ-IR each have almost the opposite effects on PD-EX and GD-EX. Exosomes have no impact on MPA, but enhance the clot strength. The impact of exosomes on aPC quality and effectiveness can be ignored or considered as a positive effect.
- Published
- 2023
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- View/download PDF
22. Kraft lignin as a bio-based ingredient for Dutch asphalts: An attributional LCA.
- Author
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Moretti C, Corona B, Hoefnagels R, van Veen M, Vural-Gürsel I, Strating T, Gosselink R, and Junginger M
- Subjects
- Biomass, Hydrocarbons, Lignin
- Abstract
In the last decade, lignin has received much attention as a feedstock to produce bio-based products. This study investigates the potential benefits of using lignin to mitigate the environmental impact of the road construction sector. An environmental life cycle assessment (LCA) of various top-layer bio-based asphalts using kraft lignin was conducted. From a cradle-to-grave perspective, lignin-based asphalts were compared with conventional asphalts. The results of the LCA revealed that the climate change impact of lignin-based asphalts could be 30-75% lower than conventional asphalts. For the other ten impact categories, trade-offs were observed. Overall, two key factors to make the environmental impact of lignin-based asphalts lower than conventional asphalts are 1) increasing the amount of bitumen-substituted and 2) using low-grade biomass fuels for process steam in the pulp mill. The substitution of weak filler with lignin was beneficial only for climate change and could lead to a worse overall environmental performance than conventional asphalts. Similarly, higher environmental impacts for lignin-based asphalts could be obtained if the pulp mill consumed natural gas to complete the energy balance to replace the part of the black liquor from which lignin is extracted. This study also includes an in-depth discussion on methodological choices such as the allocation methods for lignin, functional units, and asphalt layers considered. We believe that such a methodological discussion could be helpful to support future Product Category Rules for asphalt mixtures., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Tobias Strating is employed by an industrial partner (Roelofsgroep) that might have financial interests in the technology investigated by this article. Richard Gosselink is the inventor of a patent regarding lignin-based bio-asphalt. The other authors do not have any known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2022
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23. The role of bcsE gene in the pathogenicity of Salmonella.
- Author
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Özdemir C, Akçelik N, Neslihan Özdemir F, Evcili İ, Kahraman T, Gürsel İ, and Akçelik M
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- Animals, Biofilms, Cloning, Molecular, DNA, Bacterial, Escherichia coli genetics, HT29 Cells, Humans, Membrane Proteins physiology, Mice, Mice, Inbred BALB C, Recombinant Proteins genetics, Recombinant Proteins immunology, Recombinant Proteins metabolism, Sequence Deletion, Virulence, Bacterial Proteins physiology, Salmonella pathogenicity, Salmonella physiology, Salmonella Infections immunology, Salmonella Infections microbiology
- Abstract
The effects of the bcsE gene and BcsE protein on bacterial physiology and pathogenicity in SalmonellaTyphimurium and Salmonella Group C1 were investigated. It was observed that biofilm and pellicle formation did not occur in the bcsE gene mutants of wild-type strains. Besides, the 'rdar' (red, dry, rough) biofilm morphotype in wild-type strains changed significantly in the mutants. In terms of the bcsE gene, the swimming and swarming motility in mutant strains showed a dramatic increase compared to the wild-type strains. The Salmonella bcsE gene was cloned into Escherichia coli BL21, and the his-tagged protein produced in this strain was purified to obtain polyclonal antibodies in BALB/c mice. The antibodies were showed labeled antigen specificity to the BscE protein. As a result of immunization and systemic persistence tests carried out with BALB/c mice, BscE protein was determined to trigger high levels of humoral and cellular responses (Th1 cytokine production, IgG2a/IgG1 > 1). Systemic persistence in the liver and spleen samples decreased by 99.99% and 100% in the bcsE mutant strains. Finally, invasion abilities on HT-29 epithelial cells of wild-type strains were utterly disappeared in their bcsE gene mutant strains., (© The Author(s) 2021. Published by Oxford University Press on behalf of FEMS. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2021
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24. Review of life cycle assessments of lignin and derived products: Lessons learned.
- Author
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Moretti C, Corona B, Hoefnagels R, Vural-Gürsel I, Gosselink R, and Junginger M
- Abstract
In the last decade, the use of lignin as a bio-based alternative for fossil-based products has attracted significant attention, and the first LCAs of lignin and derived products have been conducted. Assessing side-stream products like lignin and potential benefits compared to their fossil counterparts presents complex methodological issues. This article provides a critical review of forty-two peer-reviewed LCAs regarding lignin and derived products. Methodological issues and their influence on the LCA results include the choice of the modeling approach and system boundaries, functional unit definition, impact categories considered, type of data used, handling multifunctionality and biogenic carbon modeling. The review focused on climate change impacts, as this is also the main impact category considered in most studies. Other impact categories in the comparison between lignin-based products and counterparts were also discussed with examples from the studies. Based on ten lessons learned, recommendations were provided for LCA practitioners to increase future consistency of environmental claims made about lignin and lignin-based products. The finding suggest that the environmental performance of lignin-based products is significantly affected by both 1) LCA methodological problems such as allocation practices and biogenic carbon modeling and 2) technical aspects such as the percentage of lignin in the composition of products and the selection of the fuel to replace lignin in internal energy uses. Beyond this, the reviewed LCAs showed that often lignin-based products offer better environmental performances than fossil-based products, especially for climate change., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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25. Mesenchymal stem cell derived extracellular vesicles: promising immunomodulators against autoimmune, autoinflammatory disorders and SARS-CoV-2 infection.
- Author
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Bulut Ö and GÜrsel İ
- Abstract
Discovery of novel and broad-acting immunomodulators is of critical importance for the prevention and treatment of disorders occurring due to overexuberant immune responseincluding SARS-CoV-2 triggered cytokine storm leading to lung pathology and mortality during the ongoing viral pandemic. Mesenchymal stem/stromal cells (MSCs), highly regarded for their regenerative capacities, also possessesremarkable immunoregulatory functions affecting all types of innate and adaptive immune cells. Owing to that, MSCs have been heavily investigated in clinic for the treatment of autoimmune and inflammatory diseases along with transplant rejection. Extensive research in the last decaderevealed that MSCs carry out most of their functions through paracrine factors which are soluble mediators and extracellular vesicles (EVs). EVs, including exosomes and microvesicles, are an efficient way of intercellular communication due to their unique ability to carry biological messages such as transcription factors, growth factors, cytokines, mRNAs and miRNAs over long distances. EVs originate through direct budding of the cell membrane or the endosomal secretion pathway and they consist of the cytosolic and membrane components of their parent cell. Therefore, they are able to mimic the characteristics of the parent cell, affecting the target cells upon binding or internalization. EVs secreted by MSCs are emerging as a cell-free alternative to MSC-based therapies. MSC EVs are being tested in preclinical and clinical settings where they exhibit exceptional immunosuppressivecapacity. They regulate the migration, proliferation, activation and polarization of various immune cells, promoting a tolerogenic immune response while inhibiting inflammatory response. Being as effective immunomodulators as their parent cells, MSC EVs are also preferable over MSC-based therapies due to their lower risk of immunogenicity, tumorigenicity and overall superior safety. In this review, we present the outcomes of preclinical and clinical studies utilizing MSC EVs as therapeutic agents for the treatment of a wide variety of immunological disorders., Competing Interests: CONFLICT OF INTEREST: none declared, (Copyright © 2020 The Author(s).)
- Published
- 2020
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26. Immunogenicity and protective efficacy of the recombinant Pasteurella lipoprotein E and outer membrane protein H from Pasteurella multocida A:3 in mice.
- Author
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Okay S, Özcengiz E, Gürsel I, and Özcengiz G
- Subjects
- Animals, Cloning, Molecular, Female, Mice, Mice, Inbred BALB C, Pasteurella multocida classification, Recombinant Proteins immunology, Bacterial Outer Membrane Proteins immunology, Bacterial Vaccines immunology, Lipoproteins immunology, Pasteurella Infections prevention & control, Pasteurella multocida immunology
- Abstract
Pasteurella multocida serotype A:3 is a Gram-negative bacterial pathogen, one of the causative agents of shipping fever of cattle. In this study, outer membrane protein H (ompH) and Pasteurella lipoprotein E (plpE) genes were cloned and plpEC-ompH fusion was constructed and expressed in Escherichia coli. Recombinant PlpE, OmpH and PlpEC-OmpH fusion proteins were purified and formulated with oil-based and oil-based CpG ODN adjuvants. Antibody responses in mice vaccinated with recombinant PlpE and PlpEC-OmpH proteins formulated with both adjuvants were significantly (p<0.05) increased. However, a significant (p<0.05) increment in serum IFN-γ level was only observed upon immunization with oil-based CpG formulations. Protectivity of the vaccines were evaluated via intraperitoneal challenge of mice with 10 LD50 of P. multocida A:3. The recombinant proteins PlpE and PlpEC-OmpH fusion conferred 100% protection when formulated with oil-based CpG ODN while the protectivity was found to be 80% and 60%, respectively when only oil-based adjuvant was used in respective formulations. These findings indicated that the recombinant PlpE or PlpEC-OmpH fusion proteins formulated with oil-based CpG ODN adjuvant are possible acellular vaccine candidates against shipping fever., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
27. The effects of an insertion in the 5'UTR of the AMCase on gene expression and pulmonary functions.
- Author
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Birben E, Sackesen C, Kazani S, Tincer G, Karaaslan C, Durgunsu B, Gürsel I, Wechsler ME, Israel E, and Kalayci O
- Subjects
- Adolescent, Adult, Age Factors, Case-Control Studies, Child, Enzyme-Linked Immunosorbent Assay, Female, Gene Expression, Genetic Variation, Genotype, Humans, Male, Mutagenesis, Insertional, Polymorphism, Single Nucleotide genetics, Turkey, 5' Untranslated Regions genetics, Asthma genetics, Chitinases genetics, Forced Expiratory Volume genetics
- Abstract
Background: Studies regarding the physiological role of acidic mammalian chitinase (AMCase) and the effects of its genetic variants on asthma have produced conflicting results., Objectives: We aimed to determine the genetic variants in the AMCase gene that could regulate the gene expression and thus influence disease severity., Methods: Genetic variants of the AMCase gene were determined by sequencing of asthmatics and healthy controls in up to -1 kb in the promoter region and exon 1 and 2. In an association study, a population of asthmatic (n = 504) and healthy Turkish children (n = 188) were genotyped for the observed SNPs. A replication study was performed in a North American adult population of patients with mild (n = 317) and severe (n = 145) asthma. The functional properties of the insertion were determined by promoter reporter assay, electromobility shift assay and transcription factor ELISA experiments., Results: Of the identified SNPs, only a ten base pair insertion (CAATCTAGGC) in the 5'UTR region of exon 2 was significantly associated with lower FEV(1) (β = -14.63 SE = 6.241, P = 0.019) in Turkish children with asthma. However, in the adult population, the same insertion showed a trend toward higher FEV(1). The insertion was shown to have enhancer activity and the mutant probe possessing the insertion had higher binding affinity for the nuclear extracts., Conclusion: Our study shows that a ten base pair insertion in the 5'UTR region of AMCase gene may modify gene expression and thus may affect the severity of asthma. However, its effects appear to be different in different populations., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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28. Differential immune activation following encapsulation of immunostimulatory CpG oligodeoxynucleotide in nanoliposomes.
- Author
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Erikçi E, Gursel M, and Gürsel I
- Subjects
- Animals, CD40 Antigens metabolism, Cell Proliferation drug effects, Cell Survival drug effects, Cells, Cultured, Enzyme-Linked Immunosorbent Assay, Female, Flow Cytometry, Immunization, Interferon-gamma metabolism, Interleukin-18 metabolism, Interleukin-6 metabolism, Male, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Nanostructures chemistry, Oligodeoxyribonucleotides chemistry, Reverse Transcriptase Polymerase Chain Reaction, Spleen cytology, Spleen drug effects, Liposomes chemistry, Oligodeoxyribonucleotides pharmacology
- Abstract
The immunogenicity of a vaccine formulation is closely related to the effective internalization by the innate immune cells that provide prolonged and simultaneous delivery of antigen and adjuvant to relevant antigen presenting cells. Endosome associated TLR9 recognizes microbial unmethylated CpG DNA. Clinical applications of TLR9 ligands are significantly hampered due to their pre-mature in vivo digestion and rapid clearance. Liposome encapsulation is a powerful tool to increase in vivo stability as well as enhancing internalization of its cargo to relevant immune cells. The present study established that encapsulating CpG motifs in different liposomes having different physicochemical properties altered not only encapsulation efficiency, but also the release and delivery rates that ultimately impacted in vitro and ex-vivo cytokine production rates and types. Moreover, different liposomes encapsulating CpG ODN significantly increased Th1-biased cytokines and chemokines gene transcripts Additional studies demonstrated that co-stimulatory and surface marker molecules significantly upregulated upon liposome/CpG injection. Finally, co-encapsulating model antigen ovalbumin with CpG ODN adjuvant in nanoliposomes profoundly augmented Th1 and cell mediated anti-Ova specific immune response. Collectively, this work established an unappreciated immunoregulatory property of nanoliposomes mediating immunity against protein antigen and could be harnessed to design more effective therapeutic vaccines or stand alone immunoprotective agents targeting infectious diseases, as well as cancer or allergy., (2010 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
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29. Differential and competitive activation of human immune cells by distinct classes of CpG oligodeoxynucleotide.
- Author
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Gürsel M, Verthelyi D, Gürsel I, Ishii KJ, and Klinman DM
- Subjects
- B-Lymphocytes drug effects, B-Lymphocytes immunology, Cells, Cultured, Endocytosis, Humans, Killer Cells, Natural drug effects, Killer Cells, Natural immunology, Leukocytes, Mononuclear immunology, Leukocytes, Mononuclear metabolism, Lymphocyte Activation, Monocytes drug effects, Monocytes immunology, Oligodeoxyribonucleotides classification, Oligodeoxyribonucleotides metabolism, Adjuvants, Immunologic pharmacology, Leukocytes, Mononuclear drug effects, Oligodeoxyribonucleotides pharmacology
- Abstract
Synthetic oligodeoxynucleotides (ODN) expressing "CpG motifs" show promise as immune adjuvants, antiallergens, anticancer, and immunoprotective agents. Two structurally distinct classes of CpG ODN have been identified that stimulate human PBMC. This work establishes that both types of ODN bind to and are internalized by the same individual B cells, NK cells, and monocytes. However, the intracellular localization of "D" and "K" ODN differs, as does their functional activity: "K" type ODN trigger monocytes and B cells to proliferate and secrete IL-6 and IgM, whereas "D" type ODN induce NK cells to produce IFN-gamma and monocytes to differentiate into CD83(+)/CD86(+) dendritic cells. In monocytes, these two types of ODN (which differ in backbone composition and CpG motif) cross-inhibit one another's activity. Thus, different types of CpG ODN have distinct and in some cases incompatible effects on the same cells, a finding with important implications for the therapeutic use of these agents.
- Published
- 2002
30. Chondroitin sulfate-coated polyhydroxyethyl methacrylate membrane prevents adhesion in full-thickness tendon tears of rabbits.
- Author
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Güdemez E, Ekşioğlu F, Korkusuz P, Aşan E, Gürsel I, and Hasirci V
- Subjects
- Animals, Biocompatible Materials pharmacology, Disease Models, Animal, Drug Combinations, Rabbits, Range of Motion, Articular, Tendon Injuries physiopathology, Time Factors, Tissue Adhesions etiology, Tissue Adhesions prevention & control, Chondroitin Sulfates pharmacology, Polyhydroxyethyl Methacrylate pharmacology, Tendon Injuries pathology, Tendon Injuries surgery, Wound Healing drug effects
- Abstract
Polyhydroxyethyl methacrylate (pHEMA) membranes coated on one side with chondroitin sulfate (CS) were used to block adhesion physically and to reduce friction between healing flexor tendons and the surrounding tissue in rabbit forepaws after surgical repair. Digits with pHEMA-only, standard tendon sheath repair, and with no sheath repair were the controls. Over 12 weeks the CS-coated membranes were evaluated for joint flexion, adhesion limitation, and tendon healing progress. The membranes initially allowed for better flexion (ie, for 6 weeks), but their relative superior effectiveness faded afterward. Histology showed that adhesions were less severe and healing was better in the CS-pHEMA membranes at 3 and 6 weeks. If further studies determine precise amounts or thicknesses of CS coats that will maximize its healing properties, CS-pHEMA should prove useful in clinical settings in which restoration of tendon sheath integrity with a minimum of adhesions is not possible.
- Published
- 2002
- Full Text
- View/download PDF
31. In vivo response to biodegradable controlled antibiotic release systems.
- Author
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Korkusuz F, Korkusuz P, Ekşioĝlu F, Gürsel I, and Hasirci V
- Subjects
- Animals, Biodegradation, Environmental, In Vitro Techniques, Materials Testing, Osteomyelitis drug therapy, Osteomyelitis etiology, Osteomyelitis pathology, Polymers, Prostheses and Implants adverse effects, Prosthesis-Related Infections drug therapy, Prosthesis-Related Infections etiology, Prosthesis-Related Infections pathology, Rabbits, Staphylococcal Infections drug therapy, Staphylococcal Infections etiology, Staphylococcal Infections pathology, Anti-Bacterial Agents administration & dosage, Biocompatible Materials, Drug Delivery Systems, Drug Implants
- Abstract
In this study, the major goal was to evaluate in vitro and in vivo findings by macroscopy, radiology, and histology to determine the effectiveness of therapy of experimental implant-related osteomyelitis with antibiotic carrier rods constructed of microbial polyesters. The polymers used were poly(3-hydroxybutyrate-co-4-hydroxyvalerate) [P(3-HB-co-4-HB)] and poly(3-hydroxybutyrate-co-3-hydroxy- valerate) [P(3-HB-co-3-HV)]. Both the Sulperazone and the Duocid-P(3-HB-co-4-HB) rods with a drug to polymer ratio of 1:1 (w/w) were effective in treating the bone infection that was experimentally initiated by inoculation of a hemolytic strain of Staphylococcus aureus (coagulase positive; phage type 52/52b) together with metal implants into the medullary area of rabbit tibia. Macroscopical data revealed that the effectiveness of therapy was apparent at week 6 for all categories tested. Radiological findings with Duocid- and Sulperazone-loaded P(3-HB-co-4-HB) rods improved significantly when judged by changes in periosteal elevation, widening of bone shaft, new bone formation, and soft-tissue deformation after 6 weeks of implantation. Histologically the signs of infection were found to subside by weeks 3 and 6. Inflammatory cells were replaced with bone-forming cells upon treatment with Sulperazone-P(3-HB-co-4-HB) and Duocid-P(3-HB-co-4-HB). Osteoblastic activity was prominent. Intramedullary inflammation, although still present, started to be replaced by fibrous or bony tissue. Histological findings presented the subsidence of infection. In summary, the antibiotic-loaded biopolymeric rods appeared to have potential as a new controlled-release system for the treatment of implant related osteomyelitis and chronic osteomyelitis., (Copyright 2001 John Wiley & Sons, Inc.)
- Published
- 2001
32. In vivo application of biodegradable controlled antibiotic release systems for the treatment of implant-related osteomyelitis.
- Author
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Gürsel I, Korkusuz F, Türesin F, Alaeddinoglu NG, and Hasirci V
- Subjects
- Ampicillin administration & dosage, Ampicillin therapeutic use, Animals, Cefoperazone therapeutic use, Drug Combinations, Humans, Hydroxybutyrates, Osteomyelitis etiology, Polyesters, Rabbits, Staphylococcal Infections etiology, Staphylococcus aureus, Sulbactam therapeutic use, Tibia, Absorbable Implants, Cefoperazone administration & dosage, Drug Carriers, Osteomyelitis drug therapy, Prostheses and Implants adverse effects, Prosthesis Implantation adverse effects, Staphylococcal Infections drug therapy, Sulbactam administration & dosage
- Abstract
In this study the construction and in vivo testing of antibiotic-loaded polyhydroxyalkanoate rods were planned for use in the treatment of implant-related osteomyelitis. The rods were constructed of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate), carrying 50% (w/w) Sulperazone or Duocid. They were implanted in rabbit tibia in which implant-related osteomyelitis (IRO) had been induced with Staphylococcus aureus. The effectiveness of the antibiotics in the treatment of IRO was determined. The establishment of IRO with bacterial inoculation was complete after 3 weeks with 100% infection rate in all groups. There was no contamination or super-infection. Both antibiotics were found to be highly effective against the bacteria. Following the application of Sulperazone-P(3-HB-co-4-HB) rods, no infective agents could be isolated from the infection site within the 6-week test period, indicating complete treatment of the infection. Macroscopical evaluation at follow-up revealed no drainage, minimal swelling and increase in local warmth, most probably due to the surgery rather than to a reaction towards the implant. The overall scores for radiological findings by the end of 6 weeks were 0.8/5 for the antibiotic-loaded rod implanted in the right limb, and 1.1/5 for the antibiotic-free rod implanted in the left limb. There was no statistical difference between the antibiotic-loaded and antibiotic-free polymeric rods. In vivo drug release was almost complete within the first week. One interesting observation, however, was that the therapy was still very effective even when the release rate was very high. In the SEM of in vitro tested rods, the polymeric component was unchanged in 2 weeks while the drug leached out, leaving voids behind. In vivo, however, the morphology of the implant was significantly modified within 6 weeks post-implantation. Since a substantial degree of the in vivo drug release was complete within 1 week, we believe that dissolution of the drug must be the predominant mechanism through which the drug release is controlled.
- Published
- 2001
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33. Sulbactam-cefoperazone polyhydroxybutyrate-co-hydroxyvalerate (PHBV) local antibiotic delivery system: in vivo effectiveness and biocompatibility in the treatment of implant-related experimental osteomyelitis.
- Author
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Yagmurlu MF, Korkusuz F, Gürsel I, Korkusuz P, Ors U, and Hasirci V
- Subjects
- Animals, Biocompatible Materials, Biodegradation, Environmental, Cefoperazone therapeutic use, Drug Carriers, Drug Screening Assays, Antitumor, Drug Therapy, Combination therapeutic use, Osteomyelitis diagnostic imaging, Rabbits, Radiography, Staphylococcal Infections diagnostic imaging, Sulbactam therapeutic use, Tibia, Cefoperazone administration & dosage, Drug Implants, Drug Therapy, Combination administration & dosage, Osteomyelitis drug therapy, Polyesters administration & dosage, Staphylococcal Infections drug therapy, Sulbactam administration & dosage
- Abstract
In this study, a novel antibiotic carrier system for use in the treatment of implant-related and chronic osteomyelitis was developed. Sulbactam-cefoperazone was introduced to rods of polyhydroxybutyrate-co-hydroxyvalerate (22 mol % HV, w/w), a member of a family of microbial-origin polymer that is biodegradable, biocompatible, and osteoconductive due to its piezoelectric property. The antibiotic-loaded carrier was implanted into the infection site that was induced by Staphylococcus aureus inoculation into the rabbit tibia. The effectiveness of this was assessed macroscopically, radiographically, bacteriologically, and histopathologically. Findings of infection subsided on day 15 and almost complete remission was observed on day 30. The control side that contained antibiotic-free rods, however, worsened. These findings prompted us to conclude that the novel biodegradable antibiotic carrier developed in the present study seems to be a promising candidate for use in the treatment of severe bone infection., (Copyright 1999 John Wiley & Sons, Inc.)
- Published
- 1999
- Full Text
- View/download PDF
34. Antibiotic release from biodegradable PHBV microparticles.
- Author
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Sendil D, Gürsel I, Wise DL, and Hasirci V
- Subjects
- Biodegradation, Environmental, Capsules, Gelatin chemistry, Hydrogen-Ion Concentration, Microscopy, Electron, Scanning, Microspheres, Particle Size, Polyvinyl Alcohol chemistry, Bacteria chemistry, Delayed-Action Preparations pharmacokinetics, Polyesters chemistry, Tetracycline pharmacokinetics
- Abstract
For the treatment of periodontal diseases, design of a controlled release system seemed very appropriate for an effective, long term result. In this study a novel, biodegradable microbial polyester, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV of various valerate contents containing a well established antibiotic, tetracycline, known to be effective against many of the periodontal disease related microorganisms, was used in the construction of a controlled release system. Tetracycline was loaded in the PHBV microspheres and microcapsules both in its acidic (TC) and in neutral form (TCN). Microcapsules of PHBV were prepared under different conditions using w/o/w double emulsion and their properties such as encapsulation efficiency, loading, release characteristics, and morphological properties were investigated. It was found that concentration of emulsifiers polyvinyl alcohol (PVA) and gelatin (varied between 0-4%) influenced the encapsulation efficiency appreciably. In order to increase encapsulation efficiency (from the obtained range of 18.1-30.1%) and slow down the release of the highly soluble tetracycline.HCl, it was neutralized with NaOH. Encapsulation efficiency of neutralized tetracycline was much higher (51.9-65.3%) due to the insoluble form of the drug used during encapsulation. The release behaviour of neither of the drugs was found to be of zero order. Rather the trends fitted reasonably well to Higuchi's approach for release from spherical micropheres. Biodegradability was not an appreciable parameter in the release from microcapsules because release was complete before any signs of degradation were observed.
- Published
- 1999
- Full Text
- View/download PDF
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