Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
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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.Review Citation - WoS: 52Citation - Scopus: 56Spheroid engineering in microfluidic devices(American Chemical Society, 2023) Tevlek, Atakan; Keçili, Seren; Özçelik, Özge Solmaz; Kulah, Haluk; Tekin, H. CumhurTwo-dimensional (2D) cell culture techniques are commonly employed to investigate biophysical and biochemical cellular responses. However, these culture methods, having monolayer cells, lack cell-cell and cell-extracellular matrix interactions, mimicking the cell microenvironment and multicellular organization. Three-dimensional (3D) cell culture methods enable equal transportation of nutrients, gas, and growth factors among cells and their microenvironment. Therefore, 3D cultures show similar cell proliferation, apoptosis, and differentiation properties to in vivo. A spheroid is defined as self-assembled 3D cell aggregates, and it closely mimics a cell microenvironment in vitro thanks to cell-cell/matrix interactions, which enables its use in several important applications in medical and clinical research. To fabricate a spheroid, conventional methods such as liquid overlay, hanging drop, and so forth are available. However, these labor-intensive methods result in low-throughput fabrication and uncontrollable spheroid sizes. On the other hand, microfluidic methods enable inexpensive and rapid fabrication of spheroids with high precision. Furthermore, fabricated spheroids can also be cultured in microfluidic devices for controllable cell perfusion, simulation of fluid shear effects, and mimicking of the microenvironment-like in vivo conditions. This review focuses on recent microfluidic spheroid fabrication techniques and also organ-on-a-chip applications of spheroids, which are used in different disease modeling and drug development studies.Conference Object Development of Novel Nanotoxicity Assessment Method Utilizing 3d Printing System(Elsevier, 2022) Başlar, Muhammet Semih; Öksel Karakuş, Ceyda; Aldemir Dikici, BetülUnique physicochemical properties of nanomaterials (NMs) make them a material of choice in various applications but also raise concerns about their potential toxicity. While the commercial use of nano-enabled materials is growing rapidly, their interaction with biological systems and environment are not yet fully understood [1, 2]. Traditionally, toxicity of nano-sized materials are assessed by 2D cell culture models due to their time and cost-related advantages but their simplicity often comes at the cost of accuracy. While these methods are considered as the first step in toxicological assessment of both nanosized and bulk-form materials, they fall short in mimicking the complexity of in vivo physiological environments.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.Article Citation - WoS: 43Citation - Scopus: 46Glucuronoxylan-Based Quince Seed Hydrogel: a Promising Scaffold for Tissue Engineering Applications(Elsevier, 2021) Güzelgülgen, Meltem; Özkendir İnanç, Dilce; Yıldız, Ümit Hakan; Arslan Yıldız, AhuNatural gums and mucilages from plant-derived polysaccharides are potential candidates for a tissue-engineering scaffold by their ability of gelation and biocompatibility. Herein, we utilized Glucuron-oxylanbased quince seed hydrogel (QSH) as a scaffold for tissue engineering applications. Optimization of QSH gelation was conducted by varying QSH and crosslinker glutaraldehyde (GTA) concentrations. Structural characterization of QSH was done by Fourier Transform Infrared Spectroscopy (MR). Furthermore, morphological and mechanical investigation of QSH was performed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The protein adsorption test revealed the suitability of QSH for cell attachment. Biocompatibility of QSH was confirmed by culturing NIH-3T3 mouse fibroblast cells on it. Cell viability and proliferation results revealed that optimum parameters for cell viability were 2 mg mi(-1)of QSH and 0.03 M GTA. SEM and DAPI staining results indicated the formation of spheroids with a diameter of approximately 300 pm. Furthermore, formation of extracellular matrix (ECM) microenvironment was confirmed with the Collagen Type-I staining. Here, it was demonstrated that the fabricated QSH is a promising scaffold for 3D cell culture and tissue engineering applications provided by its highly porous structure, remarkable swelling capacity and high biocompatibility. (C) 2021 Published by Elsevier B.V.Article Citation - WoS: 16Citation - Scopus: 13Fabrication of Tunable 3d Cellular Structures in High Volume Using Magnetic Levitation Guided Assembly(American Chemical Society, 2021) Onbas, Rabia; Arslan Yıldız, AhuTunable 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: 27Citation - Scopus: 28Biocomposite Scaffolds for 3d Cell Culture: Propolis Enriched Polyvinyl Alcohol Nanofibers Favoring Cell Adhesion(John Wiley and Sons Inc., 2021) Bilginer, Rumeysa; Özkendir İnanç, Dilce; Yıldız, Ümit Hakan; Arslan Yıldız, AhuThe 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: 34Citation - Scopus: 36Biomimetic Hybrid Scaffold Consisting of Co-Electrospun Collagen and Pllcl for 3d Cell Culture(Elsevier Ltd., 2019) Türker, Esra; Yıldız, Ümit Hakan; Arslan Yıldız, AhuElectrospun collagen is commonly used as a scaffold in tissue engineering applications since it mimics the content and morphology of native extracellular matrix (ECM) well. This report describes "toxic solvent free" fabrication of electrospun hybrid scaffold consisting of Collagen (Col) and Poly(L-lactide-co-epsilon-caprolactone) (PLLCL) for three-dimensional (3D) cell culture. Biomimetic hybrid scaffold was fabricated via co-spinning approach where simultaneous electrospinning of PLLCL and Collagen was mediated by polymer sacrificing agent Polyvinylpyrrolidone (PVP). Acidified aqueous solution of PVP was used to solubilize collagen without using toxic solvents for electrospinning, and then PVP was readily removed by rinsing in water. Mechanical characterizations, protein adsorption, as well as biodegradation analysis have been conducted to investigate feasibility of biomimetic hybrid scaffold for 3D cell culture applications. Electrospun biomimetic hybrid scaffold, which has 3D-network structure with 300-450 nm fiber diameters, was found to be maximizing cell adhesion through assisting NIH 3T3 mouse fibroblast cells. 3D cell culture studies confirmed that presence of collagen in biomimetic hybrid scaffold have created a major impact on cell proliferation compared to conventional 2D systems on long-term, also cell viability increased with the increasing amount of collagen. (c) 2019 Elsevier B.V. All rights reserved.