Yazar "Gultekinoglu, Merve" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Assessment of electromechanically stimulated bone marrow stem cells seeded acellular cardiac patch in a rat myocardial infarct model
    (Iop Publishing Ltd, 2021) Ozturk, Sukru; Shahbazi, Reza; Zeybek, Naciye Dilara; Kurum, Baris; Gultekinoglu, Merve; Aksoy, Eda Ayse; Demircin, Metin
    In this study, we evaluated cardiomyogenic differentiation of electromechanically stimulated rat bone marrow-derived stem cells (rt-BMSCs) on an acellular bovine pericardium (aBP) and we looked at the functioning of this engineered patch in a rat myocardial infarct (MI) model. aBP was prepared using a detergent-based decellularization procedure followed by rt-BMSCs seeding, and electrical, mechanical, or electromechanical stimulations (3 millisecond pulses of 5 V cm(-1) at 1 Hz, 5% stretching) to enhance cardiomyogenic differentiation. Furthermore, the electromechanically stimulated patch was applied to the MI region over 3 weeks. After this period, the retrieved patch and infarct region were evaluated for the presence of calcification, inflammatory reaction (CD68), patch to host tissue cell migration, and structural sarcomere protein expressions. In conjunction with any sign of calcification, a higher number of BrdU-labelled cells, and a low level of CD68 positive cells were observed in the infarct region under electromechanically stimulated conditions compared with static conditions. More importantly, MHC, SAC, Troponin T, and N-cad positive cells were observed in both infarct region, and retrieved engineered patch after 3 weeks. In a clear alignment with other results, our developed acellular patch promoted the expression of cardiomyogenic differentiation factors under electromechanical stimulation. Our engineered patch showed a successful integration with the host tissue followed by the cell migration to the infarct region.
  • Küçük Resim
    Öğe
    Polyethyleneimine brushes effectively inhibit encrustation on polyurethane ureteral stents both in dynamic bioreactor and in vivo
    (Elsevier Science Bv, 2017) Gultekinoglu, Merve; Kurum, Baris; Karahan, Siyami; Kart, Didem; Sagiroglu, Meral; Ertas, Nusret; Ulubayram, Kezban
    Polyurethane (PU) ureteral stents have been widely used as biomedical devices to aid the flow of the urine. Due to the biofilm formation and encrustation complications it has been hindered their long term clinical usage. To overcome these complications, in this study, cationic polyethyleneimine (PEI) brushes grafted on PU stents and their performances were tested both in a dynamic biofilm reactor system (in vitro) and in a rat model (in vivo). Thus, we hypothesized that PEI brushes inhibit bacterial adhesion owing to the dynamic motion of brushes in liquid environment. In addition, cationic structure of PEI disrupts the membrane and so kills the bacteria on time of contact. Cationic PEI brushes decreased the biofilm formation up to 2 orders of magnitude and approximately 50% of encrustation amount in respect to unmodified PU, in vitro. In addition, according to Atomic Absorption Spectroscopy (AAS) results, approximately 90% of encrustation was inhibited on in vivo animal models. Decrease in encrustation was clearly observed on the stents obtained from rat model, by Scanning Electron Microscopy (SEM). Also, histological evaluations showed that; PEI brush grafting decreased host tissue inflammation in close relation to decrease in biofilm formation and encrustation. As a results; dual effect of anti adhesive and contact-killing antibacterial strategy showed high efficiency on PEI brushes grafted PU stents both in vitro and in vivo. (C) 2016 Elsevier B.V. All rights reserved.