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.Conference Object Biopatterning of 3d Cellular Structures Via Contactless Magnetic Manipulation for Drug Screening(Mary Ann Liebert, 2023) Onbas, Rabia; Arslan Yıldız, AhuArticle 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.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.Article Citation - WoS: 1Citation - Scopus: 1Expression Profile of Prostaglandin Enzymes in Cystic Endometrial Hyperplasia in Dogs: the Results of a Hypothesis in Clinical Trial(Kafkas Üniversitesi, 2023) Korlu, Yeşim; Yavaş, Özkan; Aktar, Ahmet; Bozkurt, Berkay; Özyiğit, Musa Özgür; Özalp, Gözde RabiaThe expressions of prostaglandin synthesis enzymes and estrogen, progesterone receptors in canine cystic endometrial hyperplasia (CEH) were reported in this manuscript. Uterine tissue samples were collected from bitches with CEH (n=5), CEH-P (Cystic endometrial hyperplasia-Pyometra) (n=5) and healthy-negative control group, CG (n=5). Immunohistochemistry was carried out for the estrogen (ER) and progesterone receptor (PR) detection. Shock-frozen samples were utilized in mRNA extraction and Real-Time PCR was performed. Gene expression of PTGS2/COX2, PTGES, PTGER4, PGFS, PTGFR and PGR were detected higher in the CEH group compared with CG. The PGFS and PTGFR (FP) mRNA expressions were significantly increased in CEH compared with other groups. Expression of progesterone receptor mRNA (PGR) was highest in CEH and statistically different from the CEH-P group (P<0.05). No PR immunostaining was observed. ER staining had been detected in endometrial glands, endometrial stoma and myometrium, however hyperplasic glands in propria mucosa had lower or no ER scores. Based on the results of this study, the high levels of prostaglandin enzymes and low ER scores in CEH could be a preliminary step for the next stages of severe differentiation of endometrium.Conference Object On-Chip 3d Cell Culture Platform for Tumor Modeling and Drug Screening(Mary Ann Liebert, 2022) Yıldırım, Özüm; Arslan Yıldız, AhuThree-dimensional (3D) cell culture allows cell-cell and cellmatrix interactions and provides more in vivo like models rather than 2D cell culture which cannot fully mimic native tissue. 3D cell culture on microfluidics allows formation of 3D structures that mimic the physiological and chemical microenvironment for cells[1]. These microfluidic platforms also downsize bench-top laboratory to a microchip, require miniaturized reagent, and are convenient for dynamic drug screening[2]. In this study, a microfluidic platform was designed which is housing a PLLCL scaffold fabricated by electrospinning methodology.Conference Object Biofabrication by Magnetic Levitational Assembly of Cells Into Defined 3d Cellular Structures(Mary Ann Liebert, 2022) Arslan Yıldız, AhuIn the field of tissue engineering 3D (three dimensional) cell culture studies have increased over the years since they are the closest models of real tissues. Compared to the 2D models, there is a big improvement on cell growth, morphology, differentiation, gene and protein expression when 3D system is utilized. Because of these advantages 3D cell culture is commonly used for tissue engineering, artificial organ technologies, regenerative medicine, drug development, drug screening and stem cell studies. Despite promising advances in these areas, there are still unmet needs to completely fulfill all requirements. Sophisticated tools, methodologies and materials are still required for further development in tissue engineering; especially for cellular assembly, single cell level control, easy control over biofabrication system, direct forward cellular imaging and analysis. Recently, magnetic levitation technology that overcomes most of the above mentioned problems, has been utilized for the formation of 3D cellular structures. Magnetic levitational assembly of cells provide rapid, simple, cost-effective 3D cell culture formation while ensuring scaffold-free microenvironment.Conference Object Development of New Generation Hydrocolloid Bio-Ink for 3d Bioprinting(Mary Ann Liebert, 2022) Arslan Yıldız, AhuBioprinting enables the production of 3-dimensional (3D) structures by combining bioinks, living cells, extracellular matrix (ECM) components, biochemical factors, proteins, drugs; and it has recently become one of the most promising techniques in the field of tissue engineering. The successful production of the 3D structure to be created by 3D bioprinting technology depends on the properties of the bio-ink to be used. Hydrogel/hydrocolloid materials used as bio-inks are developed using synthetic and natural polymers where they have the necessary rheological properties for printing, they also have biocompatibility, low toxicity and support for cell attachment. Natural hydrogels, which have the ability to mimic the extracellular matrix structure and function at a high rate, are highly preferred bioink materials for bioprinting applications.Conference Object Development of 3d Cardiac Models Via Magnetic Manipulation for Drug Screening Studies(Mary Ann Liebert, 2022) Önbaş, Rabia; Arslan Yıldız, AhuDrug discovery and development process comprise of preclinical and clinical phases that are very intensive, long, and expensive research phases. However, drug candidates can fail in clinical trials. Toxicity is the major reason that leads to about 30% of drug development failures. Recently, the withdrawal rate of drugs from the market was increased to 33.3%from5.1%due to cardiotoxicity. When the drug fails at phase I, the reasons are probably related to 2-dimensional (2D) cell culture studies that do not represent the real tissue physiology; therefore, they provide misdirected data about the efficacy and toxicity of drug.
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