WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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  • Conference Object
    A Glucuronoxylan-Based Bio-Ink Development: Characterization and Application
    (Wiley, 2023) Yıldırım, Ömer; Arslan Yıldız, Ahu; Arslan Yıldız, Ahu; Yıldırım, Ömer; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Bioprinting 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, Ahu; Arslan Yıldız, Ahu; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    The Soft Nanodots as Fluorescent Probes for Cell Imaging: Analysis of Cell and Spheroid Penetration Behavior of Single Chain Polymer Dots
    (Wiley, 2024) Yıldız, Ümit Hakan; Arslan Yıldız, Ahu; Arslan Yıldız, Ahu; Yıldız, Ümit Hakan; 04.01. Department of Chemistry; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    This study describes the formation, size control, and penetration behavior of polymer nanodots (Pdots) consisting of single or few chain polythiophene-based conjugated polyelectrolytes (CPEs) via nanophase separation between good solvent and poor solvent of CPE. Though the chain singularity may be associated with dilution nanophase separation suggests that molecules of a good solvent create a thermodynamically driven solvation layer surrounding the CPEs and thereby separating the single chains even in their poor solvents. This statement is therefore corroborated with emission intensity/lifetime, particle size, and scattering intensity of polyelectrolyte in good and poor solvents. Regarding the augmented features, Pdots are implemented into cell imaging studies to understand the nuclear penetration and to differentiate the invasive characteristics of breast cancer cells. The python based red, green, blue (RGB) color analysis depicts that Pdots have more nuclear penetration ability in triple negative breast cancer cells due to the different nuclear morphology in shape and composition and Pdots have penetrated cell membrane as well as extracellular matrix in spheroid models. The current Pdot protocol and its utilization in cancer cell imaging are holding great promise for gene/drug delivery to target cancer cells by explicitly achieving the very first priority of nuclear intake. The penetration capability of cationic soft nanodots in to tumor models of breast cancer is demonstrated. The image analysis based on fluorescence intensity variation reveals the characteristics of translocation of nanodots in dense mediums such as tumor models.image
  • Article
    Citation - WoS: 3
    Citation - Scopus: 4
    Biopatterning of 3d Cellular Model by Contactless Magnetic Manipulation for Cardiotoxicity Screening
    (Mary Ann Liebert, Inc, 2023) Önbaş, Rabia; Arslan Yıldız, Ahu; Arslan Yıldız, Ahu; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Patterning 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) Arslan Yıldız, Ahu; Arslan Yıldız, Ahu; Onbaş, Rabia; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Spheroids 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) Arslan Yıldız, Ahu; Arslan Yıldız, Ahu; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    "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: 8
    Citation - Scopus: 11
    Cost-Effective and Rapid Prototyping of Pmma Microfluidic Device Via Polymer-Assisted Bonding
    (Springer, 2021) Sözmen, Alper Baran; Sözmen, Alper Baran; Arslan Yıldız, Ahu; 01. Izmir Institute of Technology; 03.01. Department of Bioengineering; 03. Faculty of Engineering
    Microfluidic systems are relatively new technology field with a constant need of novel and practical manufacturing materials and methods. One of the main shortcomings of current methods is the inability to provide rapid bonding, with high bonding strength, and sound microchannel integrity. Herein we propose a novel method of assembly that overcomes the mentioned limitations. Polymer-assisted bonding is a novel, rapid, simple, and inexpensive method where a polymer is solubilized in a solvent and the constituted solution is used as a bonding agent. In this study, we combined this method with utilization of several phase-changing materials (PCMs) as channel-protective agents. Glauber's salt appeared to be more suitable as a channel-protective agent compared to rest of the salts that have been used in this study. Based on the bonding strength, quality analyses, leakage tests, and SEM imaging, the superior assisting bonding solvent was determined to be dichloromethane with a PMMA concentration of 2.5% (W/V). It showed a bonding strength of 23.794 MPa and a nearly non-visible bonding layer formation of 2.83 mu m in width which is proved by SEM imaging. The said combination of PCM, solvent, and polymer concentration also showed success in leakage tests and an application of micro-droplet generator fabrication. The application was carried out to test the applicability of developed prototyping methodology, which resulted in conclusive outcomes as the droplet generator simulation run in COMSOL Multiphysics version 5.1 software. In conclusion, the developed fabrication method promises simple, rapid, and strong bonding with sharp and clear micro-channel engraving.
  • Article
    Citation - WoS: 16
    Citation - Scopus: 13
    Fabrication of Tunable 3d Cellular Structures in High Volume Using Magnetic Levitation Guided Assembly
    (American Chemical Society, 2021) Arslan Yıldız, Ahu; Arslan Yıldız, Ahu; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Tunable and reproducible size with high circularity is an important limitation to obtain three-dimensional (3D) cellular structures and spheroids in scaffold free tissue engineering approaches. Here, we present a facile methodology based on magnetic levitation (MagLev) to fabricate 3D cellular structures rapidly and easily in high-volume and low magnetic field. In this study, 3D cellular structures were fabricated using magnetic levitation directed assembly where cells are suspended and self-assembled by contactless magnetic manipulation in the presence of a paramagnetic agent. The effect of cell seeding density, culture time, and paramagnetic agent concentration on the formation of 3D cellular structures was evaluated for NIH/3T3 mouse fibroblast cells. In addition, magnetic levitation guided cellular assembly and 3D tumor spheroid formation was examined for five different cancer cell lines: MCF7 (human epithelial breast adenocarcinoma), MDA-MB-231 (human epithelial breast adenocarcinoma), SHSYSY (human bone-marrow neuroblastoma), PC-12 (rat adrenal gland pheochromocytoma), and HeLa (human epithelial cervix adenocarcinoma). Moreover, formation of a 3D coculture model was successfully observed by using MDA-MB-231 dsRED and MDA-MB-231 GFP cells. Taken together, these results indicate that the developed MagLev setup provides an easy and efficient way to fabricate 3D cellular structures and may be a feasible alternative to conventional methodologies for cellular/multicellular studies.
  • Article
    Citation - WoS: 27
    Citation - Scopus: 28
    Biocomposite Scaffolds for 3d Cell Culture: Propolis Enriched Polyvinyl Alcohol Nanofibers Favoring Cell Adhesion
    (John Wiley and Sons Inc., 2021) Bilginer, Rumeysa; Özkendir İnanç, Dilce; Arslan Yıldız, Ahu; Arslan Yıldız, Ahu; Yıldız, Ümit Hakan; 04.01. Department of Chemistry; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    The objective of this work is generation of propolis/polyvinyl alcohol (PVA) scaffold by electrospinning for 3D cell culture. Here, PVA used as co-spinning agent since propolis alone cannot be easily processed by electrospinning methodology. Propolis takes charge in maximizing biological aspect of scaffold to facilitate cell attachment and proliferation. Morphological analysis showed size of the electrospun nanofibers varied between 172-523 nm and 345-687 nm in diameter, for non-crosslinked and crosslinked scaffolds, respectively. Incorporation of propolis resulted in desired surface properties of hybrid matrix, where hybrid scaffolds highly favored protein adsorption. To examine cell compatibility, NIH-3T3 and HeLa cells were seeded on propolis/PVA hybrid scaffold. Results confirmed that integration of propolis supported cell adhesion and cell proliferation. Also, results indicated electrospun propolis/PVA hybrid scaffold provide suitable microenvironment for cell culturing. Therefore, developed hybrid scaffold could be considered as potential candidate for 3D cell culture and tissue engineering.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 6
    Boosting Up Printability of Biomacromolecule Based Bio-Ink by Modulation of Hydrogen Bonding Pairs
    (Elsevier Ltd., 2020) Köksal, Büşra; Şahin, Hasan; Önbaş, Rabia; Yıldız, Ümit Hakan; Başkurt, Mehmet; Arslan Yıldız, Ahu; Şahin, Hasan; Arslan Yıldız, Ahu; Yıldız, Ümit Hakan; 04.01. Department of Chemistry; 04.04. Department of Photonics; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    This study describes low dose UV curable and bioprintable new bioink made of hydrogen bond donor-acceptor adaptor molecule 2-isocyanatoethyl methacrylate (NCO)modified gelatin (NCO-Gel). Our theoretical calculations demonstrate that insertion of 2-isocyanatoethyl methacrylate doubles the interaction energy (500 meV) between gelatin chains providing significant contribution in interchain condensation and self-organization as compared to methacrylic anhydride modified gelatin (GelMA). The NCO-Gel exhibits peak around 1720 cm?1 referring to bidentate hydrogen bonding between H-NCO and its counterpart O[dbnd]CN[sbnd]H. These strong interchain interactions drive chains to be packed and thereby facilitating UV crosslinking. The NCO-Gel is exhibiting a rapid, 10 s gelation process by the exposure of laser (3 W, 365 nm). The dynamic light scattering characterization also reveals that NCO-Gel has faster sol to gel transition as compared to GelMA depending on the UV curing time. The NCO-Gel was found to be more firm and mechanically strong that provides advantages in molding as well as bioprinting processes. Bioprinted NCO-Gel has shown sharp borders and stable 3D geometry as compared to GelMA ink under 10 s UV curing time. The cell viability tests confirm that NCO-Gel facilitates cell proliferation and supports cell viability. We foresee that NCO-Gel bioink formulation provides a promising opportunity when low dose UV curing and rapid printing are required. © 2020 Elsevier Ltd