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, AhuArticle Anthraquinones and Macrocyclic Lactones From Endophytic Fungus Penicillium Roseopurpureum and Their Bioactivities(ACG Publications, 2024) Dizmen,B.; Üner,G.; Küçüksolak,M.; Gören,A.C.; Kırmızıbayrak,P.B.; Bedir,E.Endophytic fungi colonize the internal and distinct tissues of the host plants. In recent years, there has been growing interest in endophytic fungi as valuable sources for drug discovery based on their rich metabolic profiles consisting of novel and bioactive compounds. Accordingly, our preliminary study demonstrated that an endophyte, namely Penicillium roseopurpureum isolated from Astragalus angustifolius, had high chemical diversity with an antiproliferative effect. Herein, fermentation of P. roseopurpureum resulted in the production of five new anthraquinone-type compounds (2, 4, 6, 7, 8) together with several known compounds [11-methoxycurvularin (1: epimeric mixture of 1a and 1b), carviolin (3), 11-hydroxycurvularin (5: diastereoisomeric mixture of 5a and 5b) and 1-O-methylemodin (9)]. The structures of the new compounds were established by NMR spectroscopy and HR-MS analysis. Cytotoxicity studies demonstrated that none of the compounds except for 1 and 5 had antiproliferative activity against prostate cancer cell lines. Interestingly, 1 was found as cytotoxic, whereas 5 exhibited cytostatic properties. Also, 7-AAD/Annexin V staining supported these results by showing that 1 caused cellular death, while 5 did not show any increase in dead cell content in comparison to the control. Lastly, cell cycle analysis showed that compounds had distinctive cell cycle arrest patterns. © 2024 ACG Publications.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.Article Citation - WoS: 7Citation - Scopus: 8Ascorbic Acid Enhances the Metabolic Activity, Growth and Collagen Production of Human Dermal Fibroblasts Growing in Three-Dimensional (3D) Culture(Gazi Üniversitesi, 2023) Dikici, SerkanTissue engineering (TE) enables the development of functional synthetic substitutes to be replaced with damaged tissues and organs instead of the use of auto or allografts. A wide range of biomaterials is currently in use as TE scaffolds. Among these materials, naturally sourced ones are favorable due to being highly biocompatible and supporting cell growth and function, whereas synthetic ones are advantageous because of the high tunability on mechanical and physical properties as well as being easy to process. Alongside the advantages of synthetic polymers, they mostly show hydrophobic behavior that limits biomaterial-cell interaction and, consequently, the functioning of the developed TE constructs. In this study, we assessed the impact of L-Ascorbic acid 2-phosphate (AA2P) on improving the culture conditions of human dermal fibroblasts (HDFs) growing on a three-dimensional (3D) scaffold made of polycaprolactone (PCL) using emulsion templating. Our results demonstrated that AA2P enhances the metabolic activity and growth of HDFs as well as collagen deposition by them when supplemented in their growth medium at 50 µg/mL concentration. It showed a great potential to be used as a growth medium supplement to circumvent the disadvantages of culturing human cells on a synthetic biomaterial that is not favored in default. AA2P's potential to improve cell growth and collagen deposition may prove an effective way to culture human cells on 3D PCL PolyHIPE scaffolds for various TE applications.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: 6Citation - Scopus: 6Diagnosis of Ruminant Viral Diseases With Loop-Mediated Isothermal Amplification(Springer, 2023) Ayaz Kök, Sanem; Üstün, Selcen; Taşkent, HümeyraInfectious diseases in livestock industry are major problems for animal health, food safety, and the economy. Zoonotic diseases from farm animals are significant threat to human population as well. These are notifiable diseases listed by the World Organization for Animal Health (OIE). Rapid diagnostic methods can help keep infectious diseases under control in herds. Loop-mediated isothermal amplification (LAMP) is a simple and rapid nucleic acid amplification method that is studied widely for detection of many infectious diseases in the field. LAMP allows biosensing of target DNA or RNA under isothermal conditions with high specificity in a short period of time. An untrained user can analyze results based on color change or turbidity. Here we review LAMP assays to diagnose OIE notifiable ruminant viral diseases in literature highlighting properties of LAMP method considering what is expected from an efficient, field usable diagnostic test.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.