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: 18Citation - Scopus: 17Modifying Pickering Polymerized High Internal Phase Emulsion Morphology by Adjusting Particle Hydrophilicity(Elsevier, 2024) Durgut, Enes; Zhou, Muchu; Dikici, Betuel Aldemir; Foudazi, Reza; Claeyssens, FrederikThis study investigates the use of submicron polymeric particles with varying crosslinking densities as the sole stabilizer for producing Polymerized High Internal Phase Emulsions (PolyHIPE). We establish a direct correlation between the crosslinking density and the hydrophilicity of the polymer particles. The hydrophilicity of these particles significantly influences the morphology and rheology of HIPEs. These differences manifest as various morphological variations in the resulting PolyHIPE templates. It was discovered that by increasing the crosslinker weight percentage in the particles from 0 % to 100 %, PolyHIPEs with semi-open, open, and closed porous structures can be obtained. Furthermore, non-crosslinked particles were observed to dissolve in the continuous phase, acting as macromolecular surfactants that generate small pores akin to surfactant-stabilized structures in PolyHIPE. These findings offer fresh insights into the relationship between particle localization at the interface, HIPE rheology, and the formation of pore throats in Pickering PolyHIPEs, leading to the creation of either closed or open porous networks. Additionally, interfacial rheological results demonstrate that particles synthesized with varying monomer-to-crosslinker ratios exhibit different interfacial elasticities, which are linked to PolyHIPE morphology.Conference Object Computational Nanotoxicology: a Case Study With Silver and Zinc Nanomaterials(Elsevier, 2022) Bilgi, Eyüp; Öksel Karakuş, CeydaNanomaterials (NMs) have been the focus of basic and applied research for more than two decades. According to the updated consumer materials inventory, over 1800 commercial NMs have taken their place in the market, 42% of which are in health and wellness category1. The widespread use of NMs in health-related products made not only the human exposure to the (residues of) NMs inevitable but also the long-recognized concerns over their safety a priority. Despite this pressing need, more than 70% of commercially available nano-containing products do not include sufficient information about their physicochemical and/or toxicological characteristics.Conference Object Citation - WoS: 1Green Synthesis of Nanostructured Bioactive Glass for Dental Applications(Elsevier, 2022) Tüncer, Melisa; Yücesoy, Deniz Tanıl; Öksel Karakuş, CeydaCalcium sodium phosphosilicate (known as bioactive glass) is a biomaterial commonly used in dental care products and bone tissue engineering applications due to biocompatibility, bone-forming and dentin sensitivity reduction capability. Bioactive 45S5 glass, so-called NovaMin, comprises of 45% SiO2, 24.5% Na2O, 24.5% CaO, and 6% P2O5 (wt%). It is traditionally synthesized by wet chemical methods such as melt-quenching and sol-gel which requires high temperature heating and the use of a strong acid catalyst, which brings into the question of the possibility of introducing toxic acid residues into the final product. Therefore, there is a clear need to develop environmental-friendly bioactive glass synthesis methods or to modify existing ones in a way to uplift their environmental friendliness.Conference Object Comparative Study of the Cytotoxicity of Hydroxyapatite, Tricalcium Phosphate and Calcium Phosphate Nanomaterials on Panc-1 and Hek293 Cell Line(Elsevier, 2022) Çeşmeli, Selin; Öksel Karakuş, CeydaCalcium phosphate-based bioceramic nanoparticles have been actively used in a range of therapeutic applications. Although they are mostly considered as biocompatible materials, the circulation of nanoparticles in the bloodstream raise further questions as to what degree of cellular damage they are capable of causing once carried out to vital organs such as kidney and pancreas. Therefore, there is a clear need to explore potential cellular damage induced by commercially used bioceramic nanoparticles such as hydroxyapatite (HAp), tricalcium phosphate (TCP) and calcium phosphate (CaP).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.Article Citation - WoS: 17Citation - Scopus: 22Protein Corona Formation on Silver Nanoparticles Under Different Conditions(Elsevier, 2022) Tomak, Aysel; Yılancıoğlu, Buket; Winkler, David; Öksel Karakuş, CeydaThe surfaces of nanoparticles become covered by biomolecules in biological fluids. This protein ‘corona’ modifies materials’ characteristics and biological activity. The composition of the protein corona is dynamic, abundant biomolecules that bind first are subsequently replaced by less abundant but more tightly bound ones. Here, we explore the formation of the silver nanoparticle protein corona on exposure to cell culture media containing 10 % fetal bovine serum supplemented Dulbecco's Modified Eagle's medium. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis and liquid chromatography-mass spectrometry/mass spectrometry analysis were used to monitor how different parameters such as incubation time, heating duration, cell culture medium, incubation temperature, and the number of washes affect the nanoparticle–protein corona complex. silver nanoparticles with and without bound proteins were characterized by electron microscopy, dynamic light scattering, and ultraviolet-visible-near-IR spectroscopy. The tetrazolium-based MTT assay was used to determine viability of A549 human lung adenocarcinoma cells treated with silver nanoparticles. Characterization of the nanoparticles before and after protein binding provided insights into their changing morphology on corona formation. Our results confirmed that the physiological environment directly affects protein corona formation on nanoparticle surfaces. In particular, incubation condition-dependent differences in the amount of bound proteins were observed. This work highlights the importance of environmental drivers of protein adsorption, which should be considered when predicting and/or controlling protein targets of silver nanoparticles.Article Citation - WoS: 11Citation - Scopus: 11The Importance of Neopterin in Covid-19: The Prognostic Value and Relation With the Disease Severity(Elsevier, 2022) Rasmi, Yousef; Heidari, Nadia; Kübra Kırboğa, Kevser; Hatamkhani, Shima; Tekin, Burcu; Alipour, Shahryar; Naderi, Roya; Farnamian, Yeghaneh; Akça, İlknurCoronavirus Disease 2019 [COVID-19], caused by severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], has rapidly evolved into a global health emergency. Neopterin [NPT], produced by macrophages when stimulated with interferon [IFN-]gamma, is an essential cytokine in the antiviral immune response. NPT has been used as a marker for the early assessment of disease severity in different diseases. The leading cause of NPT production is the pro-inflammatory cytokine IFN-. Macrophage activation has also been revealed to be linked with disease severity in SARS-CoV-2 patients. We demonstrate the importance of NPT in the pathogenesis of SARS-CoV-2 and suggest that targeting NPT in SARS-CoV-2 infection may be critical in the early prediction of disease progression and provision of timely management of infected individuals.Article Citation - WoS: 12Citation - Scopus: 12Immunogenicity of a Xenogeneic Multi-Epitope Her2+ Breast Cancer Dna Vaccine Targeting the Dendritic Cell Restricted Antigen-Uptake Receptor Dec205(Elsevier, 2022) Gül, Ayten; Döşkaya, Mert; Can, Hüseyin; Karakavuk, Muhammet; Anıl İnevi, Müge; Sağlam Metiner, Pelin; Atalay Sahar, EsraBreast cancer was ranked first in global cancer incidence in 2020, and HER2 overexpression in breast cancer accounts for 20–30% of breast cancer patients. Current therapeutic strategies increase the survival rate, but resistance to them occurs frequently, and there is an urgent need to develop novel treatments such as DNA vaccines which can induce a specific and long-lasting immune response against HER2 antigens. To enhance the immunogenicity of DNA vaccines, dendritic cells (DCs) can be targeted using multi-epitope proteins that provide accurate immune focusing. For this purpose, we generated a DNA vaccine encoding a fusion protein composed of 1) in silico discovered antigenic epitopes of human and rat HER2 proteins (MeHer2) and 2) a single-chain antibody fragment (ScFv) specific for the DC-restricted antigen-uptake receptor DEC205 (ScFvDEC). The xenogeneic multi-epitope DNA vaccine (pMeHer2) encodes three only T-cell epitopes, two only B-cell epitopes, and two T and B cell epitopes, and pScFvDEC-MeHer2 vaccine additionally encodes ScFvDEC introduced at the N terminus of the MeHer2. Then, mouse groups were immunized with pScFvDEC-MeHer2, pMeHer2, pScFvDEC, pEmpty, and PBS to determine the elicited immune response. pScFvDEC-MeHer2 vaccinated mice showed a strong IgG response (P < 0.0001) and pScFvDEC-MeHer2 induced a significant IgG2a increase (P < 0.01). The percentages of both IFN-γ secreting CD4 and CD8 T cells were higher in mice immunized with pScFvDEC-MeHer2 compared with the pMeHer2. pScFvDEC-MeHer2 and pMeHer2 secreted significantly higher levels of extracellular IFN-γ compared with to control groups (P < 0.0001). In addition, the IFN-γ level of the pScFvDEC-MeHer2 vaccine group was approximately two times higher than the pMeHer2 group (P < 0.0001). Overall, this study identified the pScFvDECMeHer2 construct as a potential DNA vaccine candidate, supporting further studies to be conducted on HER2+ animal models.Article Citation - WoS: 5Citation - Scopus: 6Undescribed Polyether Ionophores From Streptomyces Cacaoi and Their Antibacterial and Antiproliferative Activities(Elsevier, 2022) Gezer, Emre; Üner, Göklem; Küçüksolak, Melis; Kurt, Mustafa Ünver; Doğan, Gamze; Ballar Kırmızıbayrak, Petek; Bedir, ErdalPolyether ionophores represent a large group of naturally occurring compounds mainly produced by Streptomyces species. With previously proven varieties of bioactivity including antibacterial, antifungal, antiparasitic, antiviral and anti-tumor effects, the discovery of undescribed polyethers leading to development of efficient therapeutics has become important. As part of our research on polyether-rich Streptomyces cacaoi, we previously performed modification studies on fermentation conditions to induce synthesis of specialized metabolites. Here, we report four undescribed and nine known polyether compounds from S. cacaoi grown in optimized conditions. Antimicrobial activity assays revealed that four compounds, including the undescribed (6), showed strong inhibitory effects over both Bacillus subtilis and methicillin-resistant Staphylococcus aureus (MRSA) growth. Additionally, K41-A and its C15-demethoxy derivative exhibited significant cytotoxicity. These results signified that selectivity of C15-demethoxy K41-A towards cancer cells was higher than K41-A, which prompted us to conduct mechanistic experiments. These studies showed that this uninvestigated compound acts as a multitarget compound by inhibiting autophagic flux, inducing reactive oxygen species formation, abolishing proteasome activity, and stimulating ER stress. Consequently, the optimized fermentation conditions of S. cacaoi led to the isolation of undescribed and known polyethers displaying promising activities.