Bioengineering / Biyomühendislik

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Citation - WoS: 7
Citation - Scopus: 9
Absorbance-Based Detection of Arsenic in a Microfluidic System With Push-And Pumping
(Elsevier, 2021) Karakuzu, Betül; Gülmez, Yekta; Tekin, H. Cumhur
Rapid and portable analysis of arsenic (As) contamination in drinking water is very important due to its adverse health effects on humans. Available commercial detection kits have shown low sensitivity and selectivity in analysis, and also they can generate harmful by-products. Microfluidic-based approaches allow portable analysis with gold nanoparticles (AuNPs) as labels. However, they need complex surface modification steps that complicate detection protocols. Due to the lack of precise sensing and affordable solution, we focused on developing a microfluidic platform that uses a push-and-pull pumping method for sensitive detection of As. In this detection principle, a sample is introduced in the microfluidic channel modified with -SH functional groups where As can bind. Then, AuNPs are given in the channel and AuNPs bind on free -SH functional groups which are not allocated with As. Absorbance measurements are conducted to detect AuNPs absorbed on the surfaces and the resulting absorbance value is inversely proportional with As concentration. The method enables detection of As down to 2.2 mu g/L concentration levels in drinking water, which is well-below the allowed maximum As concentration of 10 mu g/L in the drinking waters by the World Health Organization (WHO). The paper reveals that multiple push-and-pull pumping of fixed volume of sample and AuNPs with a syringe pump can improve the binding efficiency in the microfluidic channel. With this technique, low amounts of sample (1 mL) and short total assay time (25 min) are sufficient to detect As.
Citation - WoS: 3
Citation - Scopus: 5
Antioxidant 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.
Citation - WoS: 16
Citation - Scopus: 17
Antiproliferative Activity of (r)-4 '-methylklavuzon on Hepatocellular Carcinoma Cells and Epcam(+)/Cd133(+) Cancer Stem Cells Via Sirt1 and Exportin-1 (crm1) Inhibition
(Elsevier Ltd., 2019-10) Delman, Murat; Avcı, Sanem Tercan; Akçok, İsmail; Kanbur, Tuğçe; Erdal, Esra; Çağır, Ali
Cytotoxic effects of (R)-4'-methylklavuzon were investigated on hepatocellular carcinoma cells (HuH-7 and HepG2) and HuH-7 EpCAM(+)/CD133(+) cancer stem cells. IC50 of (R)-4'-methylklavuzon was found as 1.25 mu M for HuH-7 parental cells while it was found as 2.50 mu M for HuH-7 EpCAM(+)/CD133(+) cancer stem cells. (R)-4'-methylklavuzon tended to show more efficient in vitro cytotoxicity with its lower IC50 values on hepatocellular carcinoma cell lines compared to its lead molecule, goniothalamin and FDA-approved drugs, sorafenib and regorafenib. Cell-based Sirtuin/HDAC enzyme activity measurements revealed that endogenous Sirtuin/HDAC enzymes were reduced by 40% compared to control. SIRT1 protein levels were upregulated indicating triggered DNA repair mechanism. p53 was overexpressed in HepG2 cells. (R)-4'methylklavuzon inhibited CRM1 protein providing increased retention of p53 and RIOK2 protein in the nucleus. HuH-7 parental and EpCAM(+)/CD133(+) cancer stem cell spheroids lost intact morphology. 3D HepG2 spheroid viabilities were decreased in a correlation with upregulation in p53 protein levels. (C) 2019 Elsevier Masson SAS. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 4
Applicability of Low-Intensity Vibrations as a Regulatory Factor on Stem and Progenitor Cell Populations
(Bentham Science Publishers, 2020) Baskan, Öznur; Karadaş, Özge; Meşe, Gülistan; Özçivici, Engin
Persistent and transient mechanical loads can act as biological signals on all levels of an organism. It is therefore not surprising that most cell types can sense and respond to mechanical loads, similar to their interaction with biochemical and electrical signals. The presence or absence of mechanical forces can be an important determinant of form, function and health of many tissue types. Along with naturally occurring mechanical loads, it is possible to manipulate and apply external physical loads on tissues in biomedical sciences, either for prevention or treatment of catabolism related to many factors, including aging, paralysis, sedentary lifestyles and spaceflight. Mechanical loads consist of many components in their applied signal form such as magnitude, frequency, duration and intervals. Even though high magnitude mechanical loads with low frequencies (e.g. running or weight lifting) induce anabolism in musculoskeletal tissues, their applicability as anabolic agents is limited because of the required compliance and physical health of the target population. On the other hand, it is possible to use low magnitude and high frequency (e.g. in a vibratory form) mechanical loads for anabolism as well. Cells, including stem cells of the musculoskeletal tissue, are sensitive to high frequency, low-intensity mechanical signals. This sensitivity can be utilized not only for the targeted treatment of tissues, but also for stem cell expansion, differentiation and biomaterial interaction in tissue engineering applications. In this review, we reported recent advances in the application of low-intensity vibrations on stem and progenitor cell populations. Modulation of cellular behavior with low-intensity vibrations as an alternative or complementary factor to biochemical and scaffold induced signals may represent an increase of capabilities in studies related to tissue engineering.
Astragalus sp.
(CRC Press, 2023) Yakuboğulları, Nilgün; Bedir, Erdal
Astragalus 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.
Citation - WoS: 14
Citation - Scopus: 16
Bacterial Cellulose Based Facial Mask With Antioxidant Property and High Moisturizing Capacity
(Springer, 2021) Bilgi, Eyüp; Homan Gökçe, Evren; Bayır, Ece; Şendemir, Aylin; Özgen Özer, Kevser; Hames Tuna, Elif Esin
Bacterial cellulose (BC) produced by certain bacteria has the potential to be used in many different areas. Despite its advantageous properties compared to plant cellulose, such as high purity, mechanical strength, nanofiber mesh structure, and high-water holding capacity, its production through a biotechnological process prevents it from competing with plant counterparts in terms of cost-effectiveness. Therefore, studies have focused on the development of culture media with cost-effective BC production methods and the production of high value-added products from BC. In this study, it was aimed to develop a taurine-loaded moisturizing facial mask with antioxidant properties based on BC's high-water retention and chemical retention capacity. BC facial mask samples were characterized by Scanning Electron Microscopy (SEM) imaging, Fourier Transform Infrared (FTIR) Spectroscopy, Differential Scanning Calorimetry (DSC), Liquid Chromatography-Mass spectrometry (LC-MS), microbial and mechanical stability tests, as well as cytotoxicity tests. According to our results, produced facial mask samples did not show any cytotoxic effect on human keratinocyte (HS2) or mouse fibroblast (L-929) cell lines; it has high thermal stability, which makes it suitable for different sterilization techniques including sterilization by heat treatment. Taurine release (over 2 mu g/mL in 5 min) and microbial stability tests (no bacterial growth observed) of packaged products kept at 40 and 25 degrees C for 6 months have shown that the product preserves its characteristics for a long time. In conclusion bacterial cellulose-based facial masks are suitable for use as a facial mask, and they can be used for moisturizing and antioxidant properties by means of taurine.
Bioassay Guided Isolation of Naphthoquinones From Onosma Aksoyii, Investigation of Their Cytotoxic Properties
(Georg Thieme Verlag, 2019) Kul, Demet; Karakoyun, Çiğdem; Yılmaz, Sinem; Pirhan, Ademi Fahri; Bedir, Erdal
The genus Onosma L. (Boraginaceae) includes about 230 species, distributed mainly in the Mediterranean region and Central Asia. Major constituents of Onosma species are alkaloids, naphthoquinones, polyphenols, phytosterols, terpenoids and fatty acids [1], [2]. Naphthoquinones are naturally widespread secondary metabolites deriving from some higher plants, fungi and bacteria. They exhibit significant biological activities such as cytotoxicity, antimalarial, antibacterial, antifungal and wound healing [2], [3]. Recently naphthoquinone derivatives have also been recognized as potent topoisomerase inhibitors [4].
Citation - WoS: 12
Citation - Scopus: 16
Biocompatibility of Silicon Nitride Produced Via Partial Sintering & Tape Casting
(Elsevier Ltd., 2021) Çeçen, Berivan; Topateş, Gülsüm; Kara, Aylin; Akbulut, Serdar Onat; Havıtçıoğlu, Hasan; Kozacı, Leyla Didem
The biocompatibility of silicon nitride ceramics was proven by several studies however this study is apart from the literature in the manner of production routes that are tape casting and partial sintering. We report the tape casting route was chosen and a porous structure was obtained by partial sintering technique. Tape casting brought a smooth surface to the samples. Density and pore size distribution analysis showed that the scaffolds have low density because of the porous structure. XRD and SEM analyses were carried out to reveal the phase and microstructural characteristics of porous ceramic samples. Static contact angle measurement was done for the characterization of the wettability of the scaffolds. It revealed that the surface of the scaffolds was highly hydrophilic which is a desirable characteristic for the protein and cell adhesion. The mechanical characteristics of the scaffolds were analyzed by compression tests. Human osteosarcoma cells were used for in vitro studies. Cell-proliferation and cytotoxicity were analyzed by WST-1 and LDH, respectively. The osteoblastic behavior of the cells on the surface of the scaffolds was identified by alkaline phosphatase activity. BCA analysis was used for total protein content. The BCA and ALP results showed an increasing trend which is directly correlated with cell proliferation. Cells on the surface of the silicon nitride scaffolds were visualized by SEM and fluorescence microscopy where the images supported the in vitro analysis. Therefore, porous silicon nitride scaffolds fabricated via tape casting and partial sintering were biocompatible and they are possible candidates as bone substitute elements. © 2020 Elsevier Ltd and Techna Group S.r.l.
Citation - WoS: 26
Citation - Scopus: 28
Biocomposite Scaffolds for 3d Cell Culture: Propolis Enriched Polyvinyl Alcohol Nanofibers Favoring Cell Adhesion
(John Wiley and Sons Inc., 2021-05) Bilginer, Rumeysa; Özkendir İnanç, Dilce; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu
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.
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, Rabia
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.
Citation - WoS: 34
Citation - Scopus: 35
Biomimetic Hybrid Scaffold Consisting of Co-Electrospun Collagen and Pllcl for 3d Cell Culture
(Elsevier Ltd., 2019) Türker, Esra; Yıldız, Ümit Hakan; Arslan Yıldız, Ahu
Electrospun 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.
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
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.
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.
Biopatterning of 3d Cellular Structures Via Contactless Magnetic Manipulation for Drug Screening
(Mary Ann Liebert, 2023) Onbas, Rabia; Arslan Yıldız, Ahu
Citation - Scopus: 2
Bioprinting of Hydrogels for Tissue Engineering and Drug Screening Applications
(Elsevier, 2022) Özmen, Ece; Yıldırım, Özüm; Arslan Yıldız, Ahu
In tissue engineering, the 3-dimensional (3D) bioprinting method that enables the production of 3D structures by combining bioinks and cells has become one of the most promising technique. Over the last few years, 3D cell culture models gained importance in the development of disease model and drug development studies. The successful production of the 3D structures by 3D bioprinting mostly depends on the properties of the bioink to be used. Hydrogels, which are natural or synthetic polymers, are generally preferred as bioink materials with their high swelling ability, biocompatibility, biodegradability, and easy gelation ability. The convenience of hydrogels for varied bioprinting applications make them proper bioink materials for bioprinting of artificial tissues, tumor models, and tissue grafts. Bioprinting of functional tissues is successfully performed for years, and hydrogels are utilized as bioink in bone, vascular, neural, cartilage, cardiac, skin tissue engineering, and drug screening. In this chapter, bioprinting methodology, bioinks, hydrogel bioinks, and their applications are discussed in detail. © 2023 Elsevier Inc. All rights reserved.
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; Önbaş, Rabia; Başkurt, Mehmet; Şahin, Hasan; Arslan Yıldız, Ahu; Yıldız, Ümit Hakan
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
Citation - WoS: 2
Citation - Scopus: 2
Cloning, Expression, and Characterization of a Novel Sericin-Like Protein
(Wiley, 2022) Bostan, Fatmanur; Sürmeli, Nur Başak
Silk consists of two proteins called fibroin and sericin. While fibroin is used in the textile industry and has various biomaterial applications, sericin has been considered as waste material until recently. Sericin is a multicomponent protein and it has important properties such as biocompatibility, biodegradability, cryoprotectivity, and antioxidant. Sericin from silkworm cocoons can be obtained by chemical, enzymatic, and heat treatment methods. However, sericin obtained with these treatment methods is not of consistent and high quality. Moreover, the exposure of sericin to harsh conditions during extraction leads to inconsistencies in the composition and structure of the sericin obtained. The inconsistencies in sericin structure and composition decrease application of sericin as a biomaterial. Here, we produce a sericin-like protein (Ser4mer) with native sequence of sericin encoding four repeats of the conserved 38 amino acid motif recombinantly in Escherichia coli and characterize its structural properties. Ser4mer protein shows similar structure to native sericin and higher solubility than previously obtained recombinant sericin-like proteins. Recombinant production of a soluble sericin-like protein will significantly expand its applications as a biomaterial. In addition, recombinant production of silk proteins will allow us to understand sequence-structure relationships in these proteins.
Citation - WoS: 8
Citation - Scopus: 11
Cost-Effective and Rapid Prototyping of Pmma Microfluidic Device Via Polymer-Assisted Bonding
(Springer, 2021) Sözmen, Alper Baran; Arslan Yıldız, Ahu
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.
Citation - WoS: 13
Citation - Scopus: 15
Cytotoxic Tolerance of Healthy and Cancerous Bone Cells To Anti-Microbial Phenolic Compounds Depend on Culture Conditions
(Humana Press, 2019) Karadaş, Özge; Meşe, Gülistan; Özçivici, Engin
Carnosol and carnosic acid are polyphenolic compounds found in rosemary and sage with known anti-oxidant, anti-inflammatory, and anti-microbial properties. Here, we addressed the potential use of carnosol and carnosic acid for in vitro bone tissue engineering applications, specifically depending on their cytotoxic effects on bone marrow stromal and stem cells, and osteosarcoma cells in monolayer and 3D cultures. Carnosol and carnosic acid displayed a bacteriostatic effect on Gram-positive bacteria, especially on S. aureus. The viability results indicated that bone marrow stromal cells and bone marrow stem cells were more tolerant to the presence of carnosol compared to osteosarcoma cells. 3D culture conditions increased this tolerance further for healthy cells, while not affecting the cytotoxic potential of carnosol for osteosarcoma cells. Carnosic acid was found to be more cytotoxic for all cell types used in the study. Results suggest that phenolic compounds might have potential use as anti-microbial and anti-carcinogenic agents for bone tissue engineering with further optimization for controlled release.
Deep Convolutional Neural Networks for Viability Analysis Directly From Cell Holograms Captured Using Lensless Holographic Microscopy
(The Chemical and Biological Microsystems Society (CBMS), 2019) Delikoyun, Kerem; Çine, Ersin; Anıl İnevi, Müge; Özçivici, Engin; Özuysal, Mustafa; Tekin, Hüseyin Cumhur
Cell viability analysis is one of the most widely used protocols in the fields of biomedical sciences. Traditional methods are prone to human error and require high-cost and bulky instrumentations. Lensless digital inline holographic microscopy (LDIHM) offers low-cost and high resolution imaging. However, recorded holograms should be digitally reconstructed to obtain real images, which requires intense computational work. We introduce a deep transfer learning-based cell viability classification method that directly processes the hologram without reconstruction. This new model is only trained once and viability of each cell can be predicted from its hologram. © 2019 CBMS-0001.

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