Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
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Review Citation - WoS: 17Citation - Scopus: 16Engineering Periodontal Tissue Interfaces Using Multiphasic Scaffolds and Membranes for Guided Bone and Tissue Regeneration(Elsevier, 2024) Özkendir, Özge; Karaca, İlayda; Çullu, Selin; Yaşar, Hüsniye Nur,; Erdoğan, Oğulcan; Dikici, Serkan; Dikici, Betul AldemirPeriodontal diseases are one of the greatest healthcare burdens worldwide. The periodontal tissue compartment is an anatomical tissue interface formed from the periodontal ligament, gingiva, cementum, and bone. This multifaceted composition makes tissue engineering strategies challenging to develop due to the interface of hard and soft tissues requiring multiphase scaffolds to recreate the native tissue architecture. Multilayer constructs can better mimic tissue interfaces due to the individually tuneable layers. They have different characteristics in each layer, with modulation of mechanical properties, material type, porosity, pore size, morphology, degradation properties, and drug-releasing profile all possible. The greatest challenge of multilayer constructs is to mechanically integrate consecutive layers to avoid delamination, especially when using multiple manufacturing processes. Here, we review the development of multilayer scaffolds that aim to recapitulate native periodontal tissue interfaces in terms of physical, chemical, and biological characteristics. Important properties of multiphasic biodegradable scaffolds are highlighted and summarised, with design requirements, biomaterials, and fabrication methods, as well as post-treatment and drug/growth factor incorporation discussed.Article Citation - WoS: 6Citation - Scopus: 6Microbial Desalination Cell Treated Spent Geothermal Brine as a Nutrient Medium in Hydroponic Lettuce Cultivation: Health Risk Assessment(Elsevier, 2024) Goren, A. Y.; Eskisoy, D. N.; Genisoglu, S.; Okten, H. E.The scarcity and contamination of freshwater resources are extremely critical issues today, and the expansion of water reuse has been considered as an option to decrease its impact. Therefore, the reuse of microbial desalination (MDC)-treated spent geothermal brine for agricultural purposes arises as a good solution to prevent water contamination and provide sustainable water usage. In this study, the potential of treated spent geothermal water from MDC system as a nutrient solution for the hydroponic cultivation of lettuce was evaluated. The effects of different water samples (Hoagland solution (R1) as a control, MDC-treated water (R2), 1:1, v/v mixture of MDCtreated water and Hoagland solution (R3), 4:1, v/v mixture of MDC-treated water and Hoagland solution (R4), and tap water (R5)) on lettuce growth were considered. The application of R3 and R4 samples for hydroponic lettuce cultivation was promising since the lettuce plants uptake sufficient nutrients for their growth and productivity with low toxic metal concentrations. In addition, the chlorophyll-a, chlorophyll-b, and carotene contents of lettuce were in the range of 1.045-2.391 mg/g, 0.761-1.986 mg/g, and 0.296-0.423 mg/g in different water samples, respectively. The content of chlorophyll-a was highest in R1 (2.391 mg/g), followed by R3 (2.371 mg/g). Furthermore, the health risk assessment of heavy metal accumulations in the lettuce plants cultivated in the various water samples was determined. Results showed that heavy metal exposure via lettuce consumption is unlikely to suffer noticeable adverse health problems with values below the permissible limit value.Article Citation - WoS: 4Citation - Scopus: 4Optimizing the Dispersion of Calcium Phosphate Nanoparticles for Cellular Studies Using Statistical Design of Experiments(Elsevier, 2023) Önder, Anıl Can; Tomak, Aysel; Öksel Karakuş, CeydaThe in vitro experimentation of ceramic nanoparticles often requires their dispersion in liquid media without causing particle clumps or deteriorating sample integrity. However, the dispersion of nanoparticles using the available protocols rarely leads to stable and uniform dispersions which, in turn, raises concerns about the validity, repeatability and comparability of the findings observed in vitro. Moreover, the ability to control the final dispersion quality of ceramic nanoparticles is an essential step to obtaining optimized nanoceramic materials with desired functionality and to enhancing their performance in subsequent applications. While the need to have a comprehensive guideline for the dispersion of nanoparticles has led to several published documents and protocols, the dispersion methodology of ceramic nanoparticles and the relative contribution of the experimental parameters to the quality of resulting dispersion are still not clear. Here, we employed the statistical design of experiment (DoE) approach to systematically assess the magnitude and source of variation in dispersion quality of two different ceramic nanoparticles, hydroxyapatite and tricalcium phosphate. Using the first-order Plackett-Burman Design (PBD), nanoparticle concentration, pH and the presence of an additive were identified as the most critical factors influencing the resulting hydrodynamic size and zeta potential of the ceramic nanoparticles. Optimization using a second-order Central Composite Design (CCD) yielded a set of quadratic regression equations that were used to predict the hydrodynamic size or zeta potential of ceramic nanoparticles with high accuracy (R2, 0.88–0.92). The results of PBD screening and CCD optimization experiments were employed to prepare nanoparticle dispersions of different quality, which were then used to compare the effect of aggregation on the viability of human osteosarcoma (SaOS-2) cells. Overall, the results of this study provided insight into the role that various experimental parameters play in the colloidal stability and dispersion of ceramic nanoparticles. © 2023Article Citation - WoS: 8Citation - Scopus: 9Development of Plant-Based Biopolymer Coatings for 3d Cell Culture: Boron-Silica Quince Seed Mucilage Nanocomposites(Royal Society of Chemistry, 2023) Yılmaz, Hilal Deniz; Cengiz, Uğur; Derkuş, Burak; Arslan, Yavuz EmreSpheroid formation with spontaneous aggregation has captured interest in most cell culture studies due to its easy set-up and more reliable results. However, the economic and technical costs of the advanced systems and commercial ultra-low adhesive platforms have pushed researchers into pursuing alternatives. Nowadays, polymeric coatings, including poly-hydroxyethyl methacrylate and agar/agarose, are the commonly used polymers for non-adhesive plate fabrication, yet the costs and working solvent or heat-dependent preparation procedures maintain the need for the development of novel biomaterials. Here, we propose a greener and more economical approach for producing non-adherent surfaces and spheroid formation. For this, a plant waste-based biopolymer from quince fruit (Cydonia oblonga Miller, from Rosaceae family) seeds and boron-silica precursors were introduced. The unique water-holding capacity of quince seed mucilage (Q) was enriched with silanol and borate groups to form bioactive and hydrophilic nanocomposite overlays for spheroid studies. Moreover, 3D gel plates from the nanocomposite material were fabricated and tested in vitro as a proof-of-concept. The surface properties of coatings and the biochemical and mechanical properties of the nanocomposite materials were evaluated in-depth with techniques, and extra hydrophilic coatings were obtained. Three different cell lines were cultured on these nanocomposite surfaces, and spheroid formation with increased cellular viability was recorded on day 3 with a >200 & mu;m spheroid size. Overall, Q-based nanocomposites are believed to be a fantastic alternative for non-adherent surface fabrication due to their low-cost, easy operation, and intrinsic hydration layer forming capacity with biocompatible nature in vitro.Article Citation - WoS: 19Citation - Scopus: 21Bacterial 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 EsinBacterial 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.Article Citation - WoS: 8Citation - Scopus: 8The Role of Connexins in Breast Cancer: From Misregulated Cell Communication To Aberrant Intracellular Signaling(Taylor & Francis, 2022) Ünal, Yağmur Ceren; Yavuz, Büşra; Özçivici, Engin; Meşe Özçivici, GülistanIn spite of clinical advancements and improved diagnostic techniques, breast cancers are the leading cause of cancer-associated deaths in women worldwide. Although 70% of early breast cancers can be cured, there are no efficient therapies against metastatic breast cancers. Several factors including connexins and gap junctions play roles in breast tumorigenesis. Connexins are critical for cellular processes as a linkage between connexin mutations and hereditary disorders demonstrated their importance for tissue homeostasis. Further, alterations in their expression, localization and channel activities were observed in many cancers including breast cancer. Both channel-dependent and independent functions of connexins were reported in initiation and progression of cancers. Unlike initial reports suggesting tumor suppressor functions, connexins and gap junctions have stage, context and isoform dependent effects in breast cancers similar to other cancers. In this review, we tried to describe the current understanding of connexins in tumorigenesis specifically in breast cancers.Article Citation - WoS: 12Citation - Scopus: 12Isolation of Rosmarinic Acid and Methyl Rosmarinate as Lipoxygenase Inhibitors From Salvia Palaestina Benth. by Activity-Guided Fractionation(Elsevier, 2021) İçen, Mehmet Sina; Gürbüz, İlhan; Bedir, Erdal; Günbatan, Tuğba; Demirci, FatihSalvia palaestina aqueous and methanol extracts were prepared from the aerial parts, which were evaluated for the in vitro anti-inflammatory properties using the lipoxygenase (LO) enzyme inhibition assay. While the aqueous extract showed no activity at test concentrations, a significant (p < 0.001) lipoxygenase inhibition was detected for the methanol extract with 29% inhibition. Activity guided fractionation was carried out on the methanol extract via liquid-liquid partitioning using n-hexane, dichloromethane, ethyl acetate, and n-butanol. The ethyl acetate fraction showed statistically the best inhibition among the sub-fractions with 70% inhibition (p < 0.0001). The compounds responsible for the activity were purified, and their structures were established as rosmarinic acid, and methyl rosmarinate by spectroscopic methods. IC50 values of rosmarinic acid, and methyl rosmarinate were calculated as 0.21 and 0.02 ?M, respectively. In conclusion, the in vitro anti-inflammatory potential of S. palaestina was associated to rosmarinic acid, and methyl rosmarinate, for the first time to the best of our knowledge. © 2021 SAABArticle Citation - WoS: 5Citation - Scopus: 6Boosting 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 HakanThis 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 LtdArticle Citation - WoS: 14Citation - Scopus: 17Biocompatibility 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 DidemThe 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.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.