Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
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Conference Object A Glucuronoxylan-Based Bio-Ink Development: Characterization and Application(Wiley, 2023) Yıldırım, Ömer; Arslan Yıldız, AhuBioprinting is a trending technique that enables the fabrication of threedimensional (3D) constructs in designed shapes and with desired properties. Bioinks are one of the most significant components of bioprinting and the successful fabrication of 3D bioprinted constructs mostly depends on the features of bioinks that would be used. New generation bioinks that are soft and viscous enough, printable under low pressure, stable in cell culture, and have fast gelation mechanisms are ideal to be used in current bioprinting techniques. Hydrocolloids have said features and have similar properties to native ECM structures. Hence bioinks that are developed from hydrocolloids can be utilized for mimicking of ECM structure of soft tissues. Polysaccharidebased hydrocolloids are ideal bioink candidates with their high waterholding capacity and biocompatibility. Here, a glucuronoxylanbased newgeneration bioink was developed, and its printability was evaluated for 3D bioprinting applications. The glucuronoxylanbased hydrocolloid was obtained by water extraction of quince seeds and its utilization in bioprinting was investigated. Bioink characterization was done by FTIR and mechanical analysis. Bioprinting parameters were optimized assessing uniformity, pore factor, and shape fidelity. Then, the characterization of bioprinted constructs was performed by pore angle measurement, waterholding capacity analysis, protein adsorption, and cell viability assays. Bioprinted structures have high mechanical strength, suitable protein adsorption behavior, and waterholding capacity as high as 20fold of its own weight, which is higher than other hydrogels that were used in soft tissue engineering. Moreover, the cell viability results of fibroblast cells in the bioink were high for longterm culture. In conclusion, findings show that the developed glucuronoxylanbased bioink is a biocompatible and promising bioink material for further tissue engineering applications.Article Citation - WoS: 4Citation - Scopus: 5Antioxidant and Antimicrobial Activities of Plants Grown in the Mediterranean Region(John Wiley and Sons Inc., 2022) Kaçar, D.; Bayraktar, Oğuz; Erdem, C.; Alamri, A.S.; Galanakis, C.M.Background: The main objective of this research was to identify plant species with possible bioactivities based on their total phenol content, antioxidant, and antimicrobial properties. Therefore, different parts of 42 plant species grown in the Mediterranean region were extracted with aqueous ethanol solutions to prepare extracts with antioxidant and antimicrobial activities, mainly resulting from their total phenol contents. No detailed laboratory data on the flora of this area exists regarding their total phenol contents and total antioxidant activities. Results: Yields of extraction for each plant material were determined. Extracts were characterized based on their total phenol contents, total antioxidant (both hydrophilic and lipophilic), and antimicrobial activities using Folin–Ciocalteu, Photochemiluminescence, disc diffusion, and microdilution methods, respectively. The extract of Hypericum empetrifolium had the relatively highest total water-soluble and lipid-soluble antioxidant activities. Sarcopoterium spinosum extract had relatively high total phenol content. Preliminary screening study was conducted with the disc diffusion method to evaluate the extracts' antimicrobial activities. 26 out of 42 plant species showed significant antimicrobial activities against the growth of microorganisms. Microdilution assays were performed to evaluate the most active plant species with their minimum inhibition concentrations. H. empetrifolium, Pistacia terebinthus, Arbutus unedo, and Cistus parviflorus were the most antimicrobial plant species among those investigated. CONCLUSION: The new potential sources for the isolation of bioactive natural compounds from specific plant species could be possible with the help of this present screening study. Isolated bioactive natural compounds can be utilized as raw materials in cosmetics, nutraceuticals, food supplements, and pharmaceutical industries. © 2022 Society of Chemical Industry.Conference Object Biopatterning of 3d Cellular Structures Via Contactless Magnetic Manipulation for Drug Screening(Mary Ann Liebert, 2023) Onbas, Rabia; Arslan Yıldız, AhuReview Citation - WoS: 17Citation - Scopus: 16Engineering Periodontal Tissue Interfaces Using Multiphasic Scaffolds and Membranes for Guided Bone and Tissue Regeneration(Elsevier, 2024) Özkendir, Özge; Karaca, İlayda; Çullu, Selin; Yaşar, Hüsniye Nur,; Erdoğan, Oğulcan; Dikici, Serkan; Dikici, Betul AldemirPeriodontal diseases are one of the greatest healthcare burdens worldwide. The periodontal tissue compartment is an anatomical tissue interface formed from the periodontal ligament, gingiva, cementum, and bone. This multifaceted composition makes tissue engineering strategies challenging to develop due to the interface of hard and soft tissues requiring multiphase scaffolds to recreate the native tissue architecture. Multilayer constructs can better mimic tissue interfaces due to the individually tuneable layers. They have different characteristics in each layer, with modulation of mechanical properties, material type, porosity, pore size, morphology, degradation properties, and drug-releasing profile all possible. The greatest challenge of multilayer constructs is to mechanically integrate consecutive layers to avoid delamination, especially when using multiple manufacturing processes. Here, we review the development of multilayer scaffolds that aim to recapitulate native periodontal tissue interfaces in terms of physical, chemical, and biological characteristics. Important properties of multiphasic biodegradable scaffolds are highlighted and summarised, with design requirements, biomaterials, and fabrication methods, as well as post-treatment and drug/growth factor incorporation discussed.Article Citation - WoS: 14Citation - Scopus: 14Development of Tissue-Engineered Vascular Grafts From Decellularized Parsley Stems(Royal Society of Chemistry, 2023) Çevik, Merve; Dikici, SerkanCardiovascular diseases are mostly associated with narrowing or blockage of blood vessels, and it is the most common cause of death worldwide. The use of vascular grafts is a promising approach to bypass or replace the blocked vessels for long-term treatment. Although autologous arteries or veins are the most preferred tissue sources for vascular bypass, the limited presence and poor quality of autologous vessels necessitate seeking alternative biomaterials. Recently, synthetic grafts have gained attention as an alternative to autologous grafts. However, the high failure rate of synthetic grafts has been reported primarily due to thrombosis, atherosclerosis, intimal hyperplasia, or infection. Thrombosis, the main reason for failure upon implantation, is associated with damage or absence of endothelial cell lining in the vascular graft's luminal surface. To overcome this, tissue-engineered vascular grafts (TEVGs) have come into prominence. Alongside the well-established scaffold manufacturing techniques, decellularized plant-based constructs have recently gained significant importance and are an emerging field in tissue engineering and regenerative medicine. Accordingly, in this study, we demonstrated the fabrication of tubular scaffolds from decellularized parsley stems and recellularized them with human endothelial cells to be used as a potential TEVG. Our results suggested that the native plant DNA was successfully removed, and soft tubular biomaterials were successfully manufactured via the chemical decellularization of the parsley stems. The decellularized parsley stems showed suitable mechanical and biological properties to be used as a TEVG material, and they provided a suitable environment for the culture of human endothelial cells to attach and create a pseudo endothelium prior to implantation. This study is the first one to demonstrate the potential of the parsley stems to be used as a potential TEVG biomaterial. © 2024 The Royal Society of Chemistry.Article Citation - WoS: 3Citation - Scopus: 4Biopatterning of 3d Cellular Model by Contactless Magnetic Manipulation for Cardiotoxicity Screening(Mary Ann Liebert, Inc, 2023) Önbaş, Rabia; Arslan Yıldız, AhuPatterning cells to create three-dimensional (3D) cell culture models by magnetic manipulation is a promising technique, which is rapid, simple, and cost-effective. This study introduces a new biopatterning approach based on magnetic manipulation of cells with a bioink that consists alginate, cells, and magnetic nanoparticles. Plackett-Burman and Box-Behnken experimental design models were used to optimize bioink formulation where NIH-3T3 cells were utilized as a model cell line. The patterning capability was confirmed by light microscopy through 7 days culture time. Then, biopatterned 3D cardiac structures were formed using H9c2 cardiomyocyte cells. Cellular and extracellular components, F-actin and collagen Type I, and cardiac-specific biomarkers, Troponin T and MYH6, of biopatterned 3D cardiac structures were observed successfully. Moreover, Doxorubicin (DOX)-induced cardiotoxicity was investigated for developed 3D model, and IC50 value was calculated as 8.1 μM for biopatterned 3D cardiac structures, which showed higher resistance against DOX-exposure compared to conventional two-dimensional cell culture. Hereby, developed biopatterning methodology proved to be a simple and rapid approach to fabricate 3D cardiac models, especially for drug screening applications. Copyright 2023, Mary Ann Liebert, Inc., publishers.Book Part Astragalus sp.(CRC Press, 2023) Yakuboğulları, Nilgün; Bedir, ErdalAstragalus is one of the largest genera in Turkey and is widely distributed worldwide. The phytochemical studies on Turkish Astragalus species have presented 112 new compounds besides 63 known compounds. The overriding basis for biological activity studies is the traditional use of Astragalus roots in the Southeastern Region of Turkey to cure leukemia. As the isolated compounds did not show cytotoxic properties, a hypothesis that the biological activity of Astragalus saponins might result from the activation of the immune system came up. While Astragalus polysaccharides are used for their strong immunomodulatory activities in Chinese medicine, there are a few articles revealing the immunostimulatory properties of Astragalus saponins. Here, we summarized the compounds isolated from Turkish Astragalus species and concentrated on the immunomodulatory activities of these compounds to put forward their potential as saponin-based vaccine adjuvants. © 2024 selection and editorial matter, Ufuk Koca-Caliskan; individual chapters, the contributors.Article Citation - WoS: 6Citation - Scopus: 6Microbial Desalination Cell Treated Spent Geothermal Brine as a Nutrient Medium in Hydroponic Lettuce Cultivation: Health Risk Assessment(Elsevier, 2024) Goren, A. Y.; Eskisoy, D. N.; Genisoglu, S.; Okten, H. E.The scarcity and contamination of freshwater resources are extremely critical issues today, and the expansion of water reuse has been considered as an option to decrease its impact. Therefore, the reuse of microbial desalination (MDC)-treated spent geothermal brine for agricultural purposes arises as a good solution to prevent water contamination and provide sustainable water usage. In this study, the potential of treated spent geothermal water from MDC system as a nutrient solution for the hydroponic cultivation of lettuce was evaluated. The effects of different water samples (Hoagland solution (R1) as a control, MDC-treated water (R2), 1:1, v/v mixture of MDCtreated water and Hoagland solution (R3), 4:1, v/v mixture of MDC-treated water and Hoagland solution (R4), and tap water (R5)) on lettuce growth were considered. The application of R3 and R4 samples for hydroponic lettuce cultivation was promising since the lettuce plants uptake sufficient nutrients for their growth and productivity with low toxic metal concentrations. In addition, the chlorophyll-a, chlorophyll-b, and carotene contents of lettuce were in the range of 1.045-2.391 mg/g, 0.761-1.986 mg/g, and 0.296-0.423 mg/g in different water samples, respectively. The content of chlorophyll-a was highest in R1 (2.391 mg/g), followed by R3 (2.371 mg/g). Furthermore, the health risk assessment of heavy metal accumulations in the lettuce plants cultivated in the various water samples was determined. Results showed that heavy metal exposure via lettuce consumption is unlikely to suffer noticeable adverse health problems with values below the permissible limit value.Conference Object Biofabrication of Scaffold-Free 3d Cellular Structures Using Magnetic Levitational Assembly To Study Cardiac Toxicity(Mary Ann Liebert, 2023) Yıldız, Ahu Arslan; Arslan Yıldız, Ahu; Onbaş, RabiaSpheroids are one of the well-characterized 3D cell culture approaches for drug screening and therapeutic studies. Magnetic levitation (MagLev) is a newly developing approach to form 3D cellular structures and spheroids [1,2,3]. Magnetic levitational assembly of cells provides rapid, simple, cost-effective 3D cell culture formation while ensuring scaffold-free microenvironment. Here, our efforts are summarized in designing new magnetic levitation platform and biofabrication of 3D cellular entities via magnetic levitation for tissue engineering. Magnetic levitation and guidance of cells were provided by using a paramagnetic agent to fabricate scaffold-free 3D cellular structures. The parameters of cell density, paramagnetic agent concentration, and culturing time were optimized to obtain 3D cardiac cellular structures with tunable size, circularity, and high cell viability. Cellular and extracellular components of the 3D cellular structures were demonstrated via immunofluorescent staining. Also, 3D cardiac cellular structures showed more resistance to drug exposure compared to 2D control. In conclusion, MagLev methodology offers an easy and efficient way to fabricate 3D cellular structures for drug screening studies.Conference Object Biopatterning of 3d Cellular Structures Via Contactless Magnetic Manipulation for Drug Screening(Mary Ann Liebert, 2023) Önbaş, Rabia; Arslan Yıldız, Ahu"Patterning and manipulation techniques have been used to fabricate 3D cell cultures in tissue engineering. The contactless magnetic manipulation approach is a rapid, simple, and cost-effective method that requires paramagnetic agents [1-3] or magnetic materials [4]. Here, to obtain patterned 3D cellular structures a new alginate-based bio-ink formulation was developed to fabricate 3D cellular structures using contactless magnetic manipulation. 3D cardiac model was obtained by patterning rat cardiomyocytes. Cellular and extracellular components and cardiac-specific markers of patterned 3D cellular structures were indicated successfully. Drug response of patterned 3D cellular structures was evaluated by applying doxorubicin. Patterned 3D cardiac cellular structures showed significantly different drug response compared to conventional 2D cell cultures. In conclusion, this technique provides an easy, efficient, and low-cost methodology to fabricate 3D cardiac structures for drug screening.