Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
Browse
7 results
Search Results
Article Citation - WoS: 1Citation - Scopus: 1Evaluating the Effects of Design and Manufacturing Parameters on Friction at the Surrogate Skin-3D Textile Interface(Sage Publications Ltd, 2025-10-30) Temel-Cicek, Mevra; Cicek, Umur I.; Lloyd, Alex B.; Johnson, Andrew A.Additive manufacturing (AM) is increasingly employed in the development of 3D-printed wearables, including medical wrist supports, textiles, and protective garments. While the general tribological behavior of 3D-printed components has been widely studied, limited research has focused on the friction behavior of 3D-printed wearables when in contact with human skin, which is a crucial factor for improving wearer comfort by minimizing local skin friction. This study, therefore, investigates the influence of material type, manufacturing technology, and print parameters of 3D-printed textiles on frictional behavior against skin. Specimens were fabricated using three AM technologies: material extrusion (MEX), vat photopolymerization (VATP), and powder bed fusion (PBF). Each technology employed various materials and print parameters, specifically layer thickness (ranging from 0.05 to 0.3 mm) and print orientations (horizontal and vertical). Friction was measured using a custom-built handheld device at the interface between 3D-printed specimens and two surrogate skin models: lorica (representing the dorsal forearm) and silicone (representing the chest). The results revealed that friction was significantly influenced by both layer thickness and print orientation. For MEX specimens, acrylonitrile butadiene styrene, acrylonitrile styrene acrylate, and polycarbonate showed the highest friction, while for VATP, durable resin resulted in the highest friction coefficient. In contrast, PBF specimens exhibited very similar frictional behavior. Regarding layer thickness, higher values consistently resulted in the highest friction coefficients, regardless of manufacturing method or material type. These findings provide valuable insights for designers and engineers seeking to optimize the comfort of 3D-printed wearables, guiding the selection of suitable AM processes and parameters for products intended for direct skin contact.Article Citation - WoS: 5Citation - Scopus: 10Three Dimensional Patient-Specific Guides for Guide Pin Positioning in Reverse Shoulder Arthroplasty: An Experimental Study on Different Glenoid Types(Sage Publications Ltd, 2022-01) Sadeghi, Majid Mohammad; Kececi, Emin Faruk; Kapicioglu, Mehmet; Aralasmak, Ayse; Tezgel, Okan; Basaran, Murat Alper; Bilsel, Kerem; Mohammad Sadeghi, MajidIntroduction Incorrect positioning is one of the main factors for glenoid component loosening in reverse shoulder arthroplasty and component placement can be challenging. This study aimed to assess whether Patient-Specific Instrumentation (PSI) provides better guide pin positioning accuracy and is superior to standard guided and freehand instrumentation methods in cases of glenoid bone deformity. Materials and Methods Based on the Walch classification, five different scapula types were acquired by computed tomography (CT). For each type, two different surgeons placed a guide pin into the scapula using three different methods: freehand method, conventional non-patient-specific guide, and PSI guide. Each method was repeated five times by both surgeons. In these experiments, a total of 150 samples of scapula models were used (5 x 2 x 3 x 5 = 150). Post-operative CT scans of the samples with the guide pin were digitally assessed and the accuracy of the pin placement was determined by comparison to the preoperative planning on a three-dimensional (3D) model. Results The PSI method showed accuracies to the preoperative plan of 2.68 (SD 2.10) degrees for version angle (p < .05), 2.59 (SD 2.68) degrees for inclination angle (p < .05), and 1.55 (SD 1.26) mm for entry point offset (p < .05). The mean and standard deviation errors compared to planned values of version angle, inclination angle, and entry point offset were statistically significant for the PSI method for the type C defected glenoid and non-arthritic glenoid. Conclusion Using the PSI guide created by an image processing software tool for guide pin positioning showed advantages in glenoid component positioning over other methods, for defected and intact glenoid types, but correlation with clinical outcomes should be examined.Article Citation - WoS: 43Citation - Scopus: 49The Pleiotropic Effects of Fisetin and Hesperetin on Human Acute Promyelocytic Leukemia Cells Are Mediated Through Apoptosis, Cell Cycle Arrest, and Alterations in Signaling Networks(Sage Publications Ltd, 2015-06-17) Adan, Aysun; Baran, YusufFisetin and hesperetin, flavonoids from various plants, have several pharmaceutical activities including antioxidative, anti-inflammatory, and anticancer effects. However, studies elucidating the role and the mechanism(s) of action of fisetin and hesperetin in acute promyelocytic leukemia are absent. In this study, we investigated the mechanism of the antiproliferative and apoptotic actions exerted by fisetin and hesperetin on human HL60 acute promyelocytic leukemia cells. The viability of HL60 cells was evaluated using the MTT assay, apoptosis by annexin V/propidium iodide (PI) staining and cell cycle distribution using flow cytometry, and changes in caspase-3 enzyme activity and mitochondrial transmembrane potential. Moreover, we performed whole-genome microarray gene expression analysis to reveal genes affected by fisetin and hesperetin that can be important for developing of future targeted therapy. Based on data obtained from microarray analysis, we also described biological networks modulated after fisetin and hesperetin treatment by KEGG and IPA analysis. Fisetin and hesperetin treatment showed a concentration- and time-dependent inhibition of proliferation and induced G2/M arrest for both agents and G0/G1 arrest for hesperetin at only the highest concentrations. There was a disruption of mitochondrial membrane potential together with increased caspase-3 activity. Furthermore, fisetin- and hesperetin-triggered apoptosis was confirmed by annexin V/PI analysis. The microarray gene profiling analysis revealed some important biological pathways including mitogen-activated protein kinases (MAPK) and inhibitor of DNA binding (ID) signaling pathways altered by fisetin and hesperetin treatment as well as gave a list of genes modulated a parts per thousand yen2-fold involved in cell proliferation, cell division, and apoptosis. Altogether, data suggested that fisetin and hesperetin have anticancer properties and deserve further investigation.Article Citation - WoS: 29Citation - Scopus: 30Revealing Genome-Wide mRNA and MicroRNA Expression Patterns in Leukemic Cells Highlighted HSA-MIR as a Tumor Suppressor for Regain of Chemotherapeutic Imatinib Response due to Targeting STAT5A(Sage Publications Ltd, 2015-05-08) Kaymaz, Burcin Tezcanli; Gunel, Nur Selvi; Ceyhan, Metin; Cetintas, Vildan Bozok; Ozel, Buket; Yandim, Melis Kartal; Can, Buket KosovaBCR-ABL oncoprotein stimulates cell proliferation and inhibits apoptosis in chronic myeloid leukemia (CML). For cure, imatinib is a widely used tyrosine kinase inhibitor, but developing chemotherapeutic resistance has to be overcome. In this study, we aimed to determine differing genome-wide MicroRNA (miRNA) and messenger RNA (mRNA) expression profiles in imatinib resistant (K562/IMA-3 mu M) and parental cells by targeting STAT5A via small interfering RNA (siRNA) applications. After determining possible therapeutic miRNAs, we aimed to check their effects upon cell viability and proliferation, apoptosis, and find a possible miRNAArticle Citation - WoS: 496Citation - Scopus: 550Major Apoptotic Mechanisms and Genes Involved in Apoptosis(Sage Publications Ltd, 2016-04-09) Kiraz, Yagmur; Adan, Aysun; Yandim, Melis Kartal; Baran, Yusuf; Kartal Yandim, MelisAs much as the cellular viability is important for the living organisms, the elimination of unnecessary or damaged cells has the opposite necessity for the maintenance of homeostasis in tissues, organs and the whole organism. Apoptosis, a type of cell death mechanism, is controlled by the interactions between several molecules and responsible for the elimination of unwanted cells from the body. Apoptosis can be triggered by intrinsically or extrinsically through death signals from the outside of the cell. Any abnormality in apoptosis process can cause various types of diseases from cancer to auto-immune diseases. Different gene families such as caspases, inhibitor of apoptosis proteins, B cell lymphoma (Bcl)-2 family of genes, tumor necrosis factor (TNF) receptor gene superfamily, or p53 gene are involved and/or collaborate in the process of apoptosis. In this review, we discuss the basic features of apoptosis and have focused on the gene families playing critical roles, activation/inactivation mechanisms, upstream/downstream effectors, and signaling pathways in apoptosis on the basis of cancer studies. In addition, novel apoptotic players such as miRNAs and sphingolipid family members in various kind of cancer are discussed.Article Citation - WoS: 20Citation - Scopus: 23Apoptotic Effects of Non-Edible Parts of Punica Granatum on Human Multiple Myeloma Cells(Sage Publications Ltd, 2015-08-29) Kiraz, Yagmur; Neergheen-Bhujun, Vidushi S.; Rummun, Nawraj; Baran, YusufMultiple myeloma is of great concern since existing therapies are unable to cure this clinical condition. Alternative therapeutic approaches are mandatory, and the use of plant extracts is considered interesting. Punica granatum and its derived products were suggested as potential anticancer agents due to the presence of bioactive compounds. Thus, polypenolic-rich extracts of the non-edible parts of P. granatum were investigated for their antiproliferative and apoptotic effects on U266 multiple myeloma cells. We demonstrated that there were dose-dependent decreases in the proliferation of U266 cells in response to P. granatum extracts. Also, exposure to the extracts triggered apoptosis with significant increases in loss of mitochondrial membrane potential in U266 cells exposed to the leaves and stem extracts, while the flower extract resulted in slight increases in loss of MMP. These results were confirmed by Annexin-V analysis. These results documented the cytotoxic and apoptotic effects of P. granatum extracts on human U266 multiple myeloma cells via disruption of mitochondrial membrane potential and increasing cell cycle arrest. The data suggest that the extracts can be envisaged in cancer chemoprevention and call for further exploration into the potential application of these plant parts.Article Citation - WoS: 6Citation - Scopus: 6A Molecular and Biophysical Comparison of Macromolecular Changes in Imatinib-Sensitive and Imatinib-Resistant K562 Cells Exposed to Ponatinib(Sage Publications Ltd, 2015-09-15) Yandim, Melis Kartal; Ceylan, Cagatay; Elmas, Efe; Baran, YusufChronic myeloid leukemia (CML) is a type of hematological malignancy that is characterized by the generation of Philadelphia chromosome encoding BCR/ABL oncoprotein. Tyrosine kinase inhibitors (TKIs), imatinib, nilotinib, and dasatinib, are used for the frontline therapy of CML. Development of resistance against these TKIs in the patients bearing T315I mutation is a major obstacle in CML therapy. Ponatinib, the third-generation TKI, is novel drug that is effective even in CML patients with T315I mutation. The exact mechanism of ponatinib in CML has been still unknown. In this study, we aimed to determine the potential mechanisms and structural metabolic changes activated by ponatinib treatment in imatinib-sensitive K562 human CML cell lines and 3 mu M-imatinib-resistant K562/IMA3 CML cell lines generated at our lab. Apoptotic and antiproliferative effects of ponatinib on imatinib-sensitive and 3 mu M-imatinib-resistant K562/IMA3 CML cells were determined by proliferation and apoptosis assays. Additionally, the effects of ponatinib on macromolecules and lipid profiles were also analyzed using Fourier transform infrared spectroscopy (FTIR). Our results revealed that ponatinib inhibited cell proliferation and induced apoptosis as determined by loss of mitochondrial membrane potential, increased caspase-3 enzyme activity, and transfer of phosphatidylserine to the plasma membrane in both K562 and K562/IMA-3 cells. Furthermore, cell cycle analyses revealed that ponatinib arrested K562 and K562/IMA-3 cells at G1 phase. Moreover, ponatinib treatment created a more ordered nucleic acid structure in the resistant cells. Although the lipid to protein ratio increased in imatinib-sensitive K562 cells with a little decrease in the K562/IMA-3 cells, ponatinib treatment indicated significant changes in the lipid composition such as a significant increase in the cellular cholesterol amounts much more in the K562/IMA-3 cells than the sensitive counterparts. Unsaturation in lipids was higher in the resistant cells; however, increases in lipids without phosphate and the number of acyl chains were much higher in the K562 cells. Taken together, all these results showed powerful antiproliferative and apoptotic effects of ponatinib in both imatinib-sensitive and imatinib-resistant CML cells in a dose-dependent manner, and hence, the use of ponatinib for the treatment of TKI-resistant CML patients may be an effective treatment approach in the clinic. More importantly, these results showed that FTIR spectroscopy can detect drug-induced physiological changes in cancer drug resistance.
