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Citation Count: 225
2019 EACTS Expert Consensus on long-term mechanical circulatory support
(European Association for Cardio-Thoracic Surgery, 2019) Potapov,E.V.; Antonides,C.; Crespo-Leiro,M.G.; Combes,A.; Färber,G.; Hannan,M.M.; Gustafsson,F.
Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many - sometimes contradictory - observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device. © 2019 The Author(s).
Citation Count: 487
Advanced heart failure: a position statement of the Heart Failure Association of the European Society of Cardiology
(John Wiley and Sons Ltd, 2018) Crespo-Leiro,M.G.; Metra,M.; Lund,L.H.; Milicic,D.; Costanzo,M.R.; Filippatos,G.; Ruschitzka,F.
This article updates the Heart Failure Association of the European Society of Cardiology (ESC) 2007 classification of advanced heart failure and describes new diagnostic and treatment options for these patients. Recognizing the patient with advanced heart failure is critical to facilitate timely referral to advanced heart failure centres. Unplanned visits for heart failure decompensation, malignant arrhythmias, co-morbidities, and the 2016 ESC guidelines criteria for the diagnosis of heart failure with preserved ejection fraction are included in this updated definition. Standard treatment is, by definition, insufficient in these patients. Inotropic therapy may be used as a bridge strategy, but it is only a palliative measure when used on its own, because of the lack of outcomes data. Major progress has occurred with short-term mechanical circulatory support devices for immediate management of cardiogenic shock and long-term mechanical circulatory support for either a bridge to transplantation or as destination therapy. Heart transplantation remains the treatment of choice for patients without contraindications. Some patients will not be candidates for advanced heart failure therapies. For these patients, who are often elderly with multiple co-morbidities, management of advanced heart failure to reduce symptoms and improve quality of life should be emphasized. Robust evidence from prospective studies is lacking for most therapies for advanced heart failure. There is an urgent need to develop evidence-based treatment algorithms to prolong life when possible and in accordance with patient preferences, increase life quality, and reduce the burden of hospitalization in this vulnerable patient population. © 2018 The Authors. European Journal of Heart Failure © 2018 European Society of Cardiology
Citation Count: 52
Anti-proliferative, apoptotic and signal transduction effects of hesperidin in non-small cell lung cancer cells
(Springer, 2015) Cincin, Zeynep Birsu; Unlu, Miray; Kiran, Bayram; Bireller, Elif Sinem; Baran, Yusuf; Cakmakoglu, Bedia; Baran, Yusuf
Hesperidin, a glycoside flavonoid, is thought to act as an anti-cancer agent, since it has been found to exhibit both pro-apoptotic and anti-proliferative effects in several cancer cell types. The mechanisms underlying hesperidin-induced growth arrest and apoptosis are, however, not well understood. Here, we aimed to investigate the anti-proliferative and apoptotic effects of hesperidin on non-small cell lung cancer (NSCLC) cells and to investigate the mechanisms involved. The anti-proliferative and apoptotic effects of hesperidin on two NSCLC-derived cell lines, A549 and NCI-H358, were determined using a WST-1 colorimetric assay, a LDH cytotoxicity assay, a Cell Death Detection assay, an AnnexinV-FITC assay, a caspase-3 assay and a JC-1 assay, respectively, all in a time- and dose-dependent manner. As a control, non-cancerous MRC-5 lung fibroblasts were included. Changes in whole genome gene expression profiles were assessed using an Illumina Human HT-12v4 beadchip microarray platform, and subsequent data analyses were performed using an Illumina Genome Studio and Ingenuity Pathway Analyser (IPA). We found that after hesperidin treatment, A549 and NCI-H358 cells exhibited decreasing cell proliferation and increasing caspase-3 and other apoptosis-related activities, in conjunction with decreasing mitochondrial membrane potential activities, in a dose- and time-dependent manner. Through a GO analysis, by which changes in gene expression profiles were compared, we found that the FGF and NF-kappa B signal transduction pathways were most significantly affected in the hesperidin treated NCI-H358 and A549 NSCLC cells. Our results indicate that hesperidin elicits an in vitro growth inhibitory effect on NSCLC cells by modulating immune response-related pathways that affect apoptosis. When confirmed in vivo, hesperidin may serve as a novel anti-proliferative agent for non-small cell lung cancer.
Citation Count: 17
Apoptotic effects of non-edible parts of Punica granatum on human multiple myeloma cells
(Sage Publications Ltd, 2016) Kiraz, Yagmur; Neergheen-Bhujun, Vidushi S.; Rummun, Nawraj; Baran, Yusuf; Baran, Yusuf
Multiple 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.
Citation Count: 20
Apoptotic effects of non-edible parts of Punica granatum on human multiple myeloma cells
(Springer Science and Business Media B.V., 2016) Baran, Yusuf; Neergheen-Bhujun,V.S.; Rummun,N.; Baran,Y.
Multiple 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. © 2015, International Society of Oncology and BioMarkers (ISOBM).
Citation Count: 30
Apoptotic Effects of Quercitrin on DLD-1 Colon Cancer Cell Line
(Frontiers Media Sa, 2015) Cincin, Zeynep Birsu; Unlu, Miray; Kiran, Bayram; Bireller, Elif Sinem; Baran, Yusuf; Cakmakoglu, Bedia; Baran, Yusuf
Quercetin, which is the most abundant bioflavonoid compound, is mainly present in the glycoside form of quercitrin. Although different studies indicated that quercitrin is a potent antioxidant, the action of this compound is not well understood. In this study, we investigated whether quercitrin has apoptotic and antiproliferative effects in DLD-1 colon cancer cell lines. Time and dose dependent antiproliferative and apoptotic effects of quercitrin were subsequently determined by WST-1 cell proliferation assay, lactate dehydrogenase (LDH) cytotoxicity assay, detection of nucleosome enrichment factor, changes in caspase-3 activity, loss of mitochondrial membrane potential (MMP) and also the localization of phosphatidylserine (PS) in the plasma membrane. There were significant increases in caspase-3 activity, loss of MMP, and increases in the apoptotic cell population in response to quercitrin in DLD-1 colon cancer cells in a time- and dose-dependent manner. These results revealed that quercitrin has antiproliferative and apoptotic effects on colon cancer cells. Quercitrin activity supported with in vivo analyses could be a biomarker candicate for early colorectal carcinoma.
Citation Count: 38
Autologous rabbit adipose tissue-derived mesenchymal stromal cells for the treatment of bone injuries with distraction osteogenesis
(Elsevier Sci Ltd, 2013) Sunay, Ozgur; Can, Geylani; Cakir, Zeynep; Denek, Ziya; Kozanoglu, Ilknur; Erbil, Guven; Baran, Yusuf; Baran, Yusuf
Background aims. Adipose tissue-derived mesenchymal stromal cells (MSCs) have a higher capacity for proliferation and differentiation compared with other cell lineages. Although distraction osteogenesis is the most important therapy for treating bone defects, this treatment is restricted in many situations. The aim of this study was to examine the therapeutic potential of adipose tissue-derived MSCs and osteoblasts differentiated from adipose tissue-derived MSCs in the treatment of bone defects. Methods. Bone defects were produced in the tibias of New Zealand rabbits that had previously undergone adipose tissue extraction. Tibial osteotomy was performed, and a distractor was placed on the right leg of the rabbits. The rabbits were placed in control (group I), stem cell (group II) and osteoblast-differentiated stem cell (group III) treatment groups. The rabbits were sacrificed, and the defect area was evaluated by radiologic, biomechanical and histopathologic tests to examine the therapeutic effects of adipose tissue-derived MSCs. Results. Radiologic analyses revealed that callus density and the ossification rate increased in group III compared with group I and group II. In biomechanical tests, the highest ossification rate was observed in group III. Histopathologic studies showed that the quality of newly formed bone and the number of cells active in bone formation were significantly higher in group III rabbits compared with group I and group II rabbits. Conclusions. These data reveal that osteoblasts differentiated from adipose tissue-derived MSCs shorten the consolidation period of distraction osteogenesis. Stem cells could be used as an effective treatment for bone defects.
Citation Count: 16
Biodiversity, drug discovery, and the future of global health: Introducing the biodiversity to biomedicine consortium, a call to action
(Univ Edinburgh, Global Health Soc, 2017) Neergheen-Bhujun, Vidushi; Awan, Almas Taj; Baran, Yusuf; Bunnefeld, Nils; Chan, Kit; Edison Dela Cruz, Thomas; Kagansky, Alexander; Baran, Yusuf
[No Abstract Available]
Citation Count: 4
Biodiversity: the overlooked source of human health
(Cell Press, 2023) Linhares, Yuliya; Kaganski, Alexander; Agyare, Christian; Kurnaz, Isil A.; Neergheen, Vidushi; Kolodziejczyk, Bartlomiej; Bueso, Yensi Flores
Biodiversity is the measure of the variation of lifeforms in a given ecological system. Biodiversity provides ecosystems with the robustness, stability, and re-silience that sustains them. This is ultimately essential for our survival because we depend on the services that natural ecosystems provide (food, fresh water, air, climate, and medicine). Despite this, human activity is driving an unprece-dented rate of biodiversity decline, which may jeopardize the life-support sys-tems of the planet if no urgent action is taken. In this article we show why biodiversity is essential for human health. We raise our case and focus on the biomedicine services that are enabled by biodiversity, and we present known and novel approaches to promote biodiversity conservation.
Citation Count: 12
Bisphosphonate treatment and radiotherapy in metastatic breast cancer
(Humana Press inc, 2008) Ural, A. Ugur; Avcu, Ferit; Baran, Yusuf; Baran, Yusuf
Patients with advanced breast cancer frequently develop metastasis to bone. Bone metastasis results in intractable pain and high risk of pathologic fractures due to osteolysis. The treatment of breast cancer patients with bone metastases requires a multidisciplinary approach. Radiotherapy is an established treatment for metastatic bone pain. It may be delivered either as a localized low dose treatment for localized bone pain or systemically for more widespread symptoms. Bisphosphonates have been shown to reduce morbidity and bone pain from bone metastases when given to patients with metastatic bone disease. In vivo studies indicate that early bisphosphonates administration in combination with radiotherapy improves remineralization and restabilization of osteolytic bone metastases in animal tumor models. This review focused on a brief discussion about biology of bone metastases, the effects of radiotherapy and bisphosphonate therapy, and possible mechanisms of combination therapy in metastatic breast cancer patients.
Citation Count: 8
The case of a cyst hydatid localized within the interatrial septum
(2004) Karabay,Ö.; Önen,A.; Yildiz,F.; Yilmaz,E.; Erdal,A.C.; Şanli,A.; Açikel,Ü.
The ratio of cardiac involvement of Echinoccocus granulosus is 0.02-2% and although seen rarely, involvement of the interatrial septum has also been reported in the published literature. The present case was a 19-year-old male university student admitted to hospital with complaints of headache and dizziness. Computerized tomography of the cranium revealed a cystic mass located at the frontal region and enucleation of the cyst was performed during surgery. A cystic lesion 5 × 4 cm in size was detected within the interatrial septum on two-dimensional transthoracic echocardiography during the postoperative period and the patient was referred to our clinic. Open heart surgery was performed and a hydatid cyst that involved the interatrial septum was enucleated. The cyst wall was sutured to the interatrial septum. No complications developed during the postoperative period. The patient was discharged on the fifth day of hospitalization and medical therapy was started with albendazole. Copyright © 2004 by the Japanese Heart Journal.
Citation Count: 7
Comparative development of knowledge-based bioeconomy in the European Union and Turkey
(informa Healthcare, 2014) Ozan, Didem Celikkanat; Baran, Yusuf; Baran, Yusuf
Biotechnology, defined as the technological application that uses biological systems and living organisms, or their derivatives, to create or modify diverse products or processes, is widely used for healthcare, agricultural and environmental applications. The continuity in industrial applications of biotechnology enables the rise and development of the bioeconomy concept. Bioeconomy, including all applications of biotechnology, is defined as translation of knowledge received from life sciences into new, sustainable, environment friendly and competitive products. With the advanced research and eco-efficient processes in the scope of bioeconomy, more healthy and sustainable life is promised. Knowledge-based bioeconomy with its economic, social and environmental potential has already been brought to the research agendas of European Union (EU) countries. The aim of this study is to summarize the development of knowledge-based bioeconomy in EU countries and to evaluate Turkey's current situation compared to them. EU-funded biotechnology research projects under FP6 and FP7 and nationally-funded biotechnology projects under The Scientific and Technological Research Council of Turkey (TUBITAK) Academic Research Funding Program Directorate (ARDEB) and Technology and Innovation Funding Programs Directorate (TEYDEB) were examined. In the context of this study, the main research areas and subfields which have been funded, the budget spent and the number of projects funded since 2003 both nationally and EU-wide and the gaps and overlapping topics were analyzed. In consideration of the results, detailed suggestions for Turkey have been proposed. The research results are expected to be used as a roadmap for coordinating the stakeholders of bioeconomy and integrating Turkish Research Areas into European Research Areas.
Citation Count: 13
Cumulative clinical experience from a decade of use: imatinib as first-line treatment of chronic myeloid leukemia
(Dove Medical Press Ltd, 2012) Baran, Yusuf; Saydam, Guray; Baran, Yusuf
Chronic myeloid leukemia (CML) is a malignant disease that originates in the bone marrow and is designated by the presence of the Philadelphia (Ph+) chromosome, a translocation between chromosomes 9 and 22. Targeted therapy against CML commenced with the development of small-molecule tyrosine kinase inhibitors (TKIs) exerting their effect against the oncogenic breakpoint cluster region (BCR)-ABL fusion protein. Imatinib emerged as the first successful example of a TKI used for the treatment of chronic-phase CML patients and resulted in significant improvements in response rate and overall survival compared with previous treatments. However, a significant portion of patients failed to respond to the therapy and developed resistance against imatinib. Second-generation TKIs nilotinib and dasatinib were to have higher efficiency in clinical trials in imatinib-resistant or intolerant CML patients compared with imatinib. Identification of novel strategies such as dose escalation, drug combination therapy, and use of novel BCR-ABL inhibitors may eventually overcome resistance against BCR-ABL TKIs. This article reviews the history of CML, including the treatment strategies used prediscovery of TKIs and the preclinical and clinical data obtained after the use of imatinib, and the second-generation TKIs developed for the treatment of CML.
Citation Count: 5
Deep sequencing reveals two jurkat subpopulations with distinct miRNA profiles during camptothecin-induced apoptosis
(Tubitak Scientific & Technological Research Council Turkey, 2018) Erdogan, Ipek; Cosacak, Mehmet Ilyas; Nalbant, Ayten; Akgul, Bunyamin; Akgül, Bünyamin
MicroRNAs (miRNAs) are small noncoding RNAs of about 19-25 nt that regulate gene expression posttranscriptionally under various cellular conditions, including apoptosis. The miRNAs involved in modulation of apoptotic events in T cells are partially known. However, heterogeneity associated with cell lines makes it difficult to interpret gene expression signatures, especially in cancer-related cell lines. Treatment of the Jurkat T-cell leukemia cell line with the universal apoptotic drug, camptothecin, resulted in identification of two Jurkat subpopulations: one that is sensitive to camptothecin and another that is rather intrinsically resistant. We sorted apoptotic Jurkat cells from nonapoptotic ones prior to profiling miRNAs through deep sequencing. Our data showed that a total of 184 miRNAs were dysregulated. Interestingly, the apoptotic and nonapoptotic subpopulations exhibited distinct miRNA expression profiles. In particular, 6 miRNAs were inversely expressed in these two subpopulations. The pyrosequencing results were validated by real-time qPCR. Altogether, these results suggest that miRNAs modulate apoptotic events in T cells and that cellular heterogeneity requires careful interpretation of miRNA expression profiles obtained from drug-treated cell lines.
Citation Count: 0
Development of AB3-Type Novel Phthalocyanine and Porphyrin Photosensitizers Conjugated with Triphenylphosphonium for Higher Photodynamic Efficacy
(Amer Chemical Soc, 2022) Onal, Emel; Tuncel, Ozge; Vatansever, Ipek Erdogan; Albakour, Mohamad; Celik, Gizem Gumusgoz; Kucuk, Tugba; Ozcelik, Serdar
There are a number of lipophilic cations that can be chosen; the triphenylphosphonium (TPP) ion is particularly unique for mitochondrion targeting, mainly due to its simplicity in structure and ease to be linked to the target molecules. In this work, mitochondrion-targeted AB3-type novel phthalocyanine and porphyrin photosensitizers (PSs) were synthesized and their photophysical photochemical properties were defined. Fluores-cence quantum yields (phi F) are 0.009, 0.14, 0.13, and 0.13, and the singlet-oxygen quantum yields (phi Delta) are 0.27, 0.75, 0.57, and 0.58 for LuPcPox(OAc), AB3TPP-Pc, AB3TPP-Por-C4, and AB3TPP-Por-C6, respectively. To evaluate the photodynamic efficacy of the TPP-conjugated PS cell viabilities of A549 and BEAS-2B lung cells were comparatively measured and IC-50 values were determined. AB3TPP-Por-C4, AB3TPP-Por-C6, and AB3TPP-Pc compounds compared to the reference molecules ZnPc and H2TPP were found to be highly cytotoxic (sub-micromolar concentration) under the light. LuPcPox(OAc) is the most effective molecule regarding cell killing (the activity). The cell killing of the TPP-conjugated porphyrin derivatives exhibits a similar response compared to LuPcPox(OAc) when the light absorbing factor of the PS is normalized at 660 nm: TPP-conjugated porphyrins absorb less light (lower extinction coefficient) but produce more radical species (higher singlet-oxygen quantum yield) and therefore effectively kill the cells. The singlet oxygen-producing capacity of AB3TPP-Pc is almost 3 times higher compared to LuPcPox(OAc) and 50% more efficient with respect to ZnPc, suggesting that TPP-conjugated phthalocyanine may serve as a good photosensitizer for photodynamic therapy (PDT). The high singlet oxygen generation capacity of these novel TPP-conjugated porphyrin and phthalocyanine PS suggests that they might be useful for PDT requiring lower photosensitizer concentration and reduced energy deposited through less light exposure.
Citation Count: 11
Effect of Alkali Metal Hydroxides on the Morphological Development and Optical Properties of Ceria Nanocubes Under Hydrothermal Conditions
(Amer Scientific Publishers, 2011) Kepenekci, Ozlem; Emirdag-Eanes, Mehtap; Demir, Mustafa M.; Demir, Mustafa
Nanocrystalline cerium(IV) oxide (CeO2, ceria) particles were produced via the hydrothermal treatment of cerium nitrate hexahydrate with various alkali metal hydroxides (MOH: M = Li, Na, K) Experimental conditions such as [MOH], reaction temperature, and reaction time were studied Particle morphology as well as size of crystallites was precisely controlled by choice of experimental conditions. While rod-shaped particles were obtained at 120 degrees C, well-defined nanocubes were formed at higher temperatures regardless of the choice of MOH. Examination of particle growth kinetics, in the final stages of crystallization, showed that particle growth rate is controlled by two different mechanisms. Grain boundary diffusion controls the particle growth in the presence of NaOH with an activation energy of 113.8 kj/mol and surface diffusion for LiOH ad KOH with the activation energy of 43.0-150.9 kj/mol, respectively. In addition, the particles exhibit strong violet and blue emissions at 400 nm and 370 nm. The former emission originates from excitation of a wide band gap of CeO2. The latter one is attributed to the trivalency of the cerium ion and appears to be sensitive to all the experimental conditions studied. Both extending reaction time and increasing temperature reduce the intensity of the 370 nm emission and increase the intensity of the 400 nm emission.
Citation Count: 11
Effect of alkali metal hydroxides on the morphological development and optical properties of ceria nanocubes under hydrothermal conditions
(2011) Kepenekçi O.; Emirdag-Eanes M.; Demir, M.M.
Nanocrystalline cerium(IV) oxide (CeO2, ceria) particles were produced via the hydrothermal treatment of cerium nitrate hexahydrate with various alkali metal hydroxides (MOH: M = Li, Na, K). Experimental conditions such as [MOH], reaction temperature, and reaction time were studied. Particle morphology as well as size of crystallites was precisely controlled by choice of experimental conditions. While rod-shaped particles were obtained at 120 °C, well-defined nanocubes were formed at higher temperatures regardless of the choice of MOH. Examination of particle growth kinetics, in the final stages of crystallization, showed that particle growth rate is controlled by two different mechanisms. Grain boundary diffusion controls the particle growth in the presence of NaOH with an activation energy of 113.8 kj/mol and surface diffusion for LiOH ad KOH with the activation energy of 43.0-150.9 kj/mol, respectively. In addition, the particles exhibit strong violet and blue emissions at 400 nm and 370 nm. The former emission originates from excitation of a wide band gap of CeO2. The latter one is attributed to the trivalency of the cerium ion and appears to be sensitive to all the experimental conditions studied. Both extending reaction time and increasing temperature reduce the intensity of the 370 nm emission and increase the intensity of the 400 nm emission. Copyright © 2011 American Scientific Publishers.
Citation Count: 3
Effect of CNT incorporation on PAN/PPy nanofibers synthesized by electrospinning method
(Tubitak Scientific & Technological Research Council Turkey, 2020) Ince Yardimci, Atike; Tanoglu, Metin; Yilmaz, Selahattin; Selamet, Yusuf; Tanoğlu, Metin
In this study, carbon nanotubes (CNTs) added polyacrylonitrile/polypyrrole (PAN/PPy) electrospun nanofibers were produced. Average diameters of the nanofibers were measured as 268 and 153 nm for 10 and 25 wt% of PPy contents, respectively. A relatively higher strain to failure values (23.3%) were observed for the low PPy content. When as-grown CNTs (1 and 4 wt%) were added into the PAN/PPy blends, disordered nanofibers were observed to form within the microstructure. To improve the interfacial properties of CNTs/PAN/PPy composites, CNTs were functionalized with H2SO4/HNO3/HCl solution. The functionalized CNTs were well dispersed within the nanofibers and aligned along the direction of nanofibers. Therefore, beads formation on nanofibers decreased. The impedance of the nanofibers was found to decrease with the PPy content and CNT addition. These nanofibers had a great potential to be used as an electrochemical actuator or a tissue engineering scaffold.
Citation Count: 6
Effect of cobalt-60 (γ radiation) on multidrug-resistant multiple myeloma cell lines
(Portland Press Ltd, 2011) Mutlu, Pelin; Baran, Yusuf; Ural, A. Ugur; Avcu, Ferit; Dirican, Bahar; Beyzadeoglu, Murat; Gunduz, Ufuk; Baran, Yusuf
Emergence of resistance to chemotherapy and radiotherapy is a major obstacle for the successful treatment of MM (multiple myeloma). Prednisone, vincristine and melphalan are commonly used chemotherapeutic agents for the treatment of MM. In the current study, we examined the presence of possible cross-resistance between these drugs and gamma (gamma) radiation. Prednisone, vincristine and melphalan resistant RPMI-8226 and U-266 MM cells were generated by stepwise increasing concentrations of the drugs. The sensitive and resistant cells were exposed to 200- and 800 cGy gamma radiation, and proliferation was examined by XTT {2,3-bis(2-methoxy-4-nitro-5-sulfopheny1)-5-Rphenylamino)carbonyl]-2H-tetrazolium hydroxide) assay. The results showed that Prednisone- and melphalan-resistant RPMI-8226 cells were also cross-resistant to 200 and 800 cGy gamma radiation application, while vincristine-resistant cells did not show resistance. On the other hand, Prednisone-, vincristine- and melphalan-resistant U-266 cells showed cross-resistance to 200- and 800 cGy gamma radiation application. These results demonstrated that MM cells resistant to anticancer agents respond to radiation in different levels. These findings may be important in the clinical applications of radiation therapy in the treatment of vincristine resistant MM.
Citation Count: 34
Effect of Molecular Architecture on Cell Interactions and Stealth Properties of PEG
(Amer Chemical Soc, 2017) Ozer, Imran; Tomak, Aysel; Zareie, Hadi M.; Baran, Yusuf; Bulmus, Volga; Baran, Yusuf
PEGylation, covalent attachment of PEG to therapeutic biomolecules, in which suboptimal pharmacokinetic profiles limiting their therapeutic utility are of concern, is a widely applied technology. However, this technology has been challenged by reduced bioactivity of biomolecules upon PEGylation and immunogenicity of PEG triggering immune response and abrogating clinical efficacy, which collectively necessitate development of stealth polymer alternatives. Here we demonstrate that comb-shape poly[oligo(ethylene glycol) methyl ether methacrylate](POEGMA); a stealth polymer alternative, has a more compact structure than PEG and self-organize into nanoparticles in a molecular weight dependent manner. Most notably, we show that comb shape POEGMA promotes significantly higher cellular uptake and exhibits less steric hindrance imposed on the conjugated biomolecule than PEG. Collectively, comb-shape POEGMA offers a versatile alternative to PEG for stealth polymer-biomolecule conjugation applications.

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