Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.Yildiz, Ahu Arslan

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  • Article
    Citation - WoS: 4
    Citation - Scopus: 5
    Near-Infrared Emissive Super Penetrating Conjugated Polymer Dots for Intratumoral Imaging in 3d Tumor Spheroid Models
    (Wiley, 2024) Karabacak, Soner; Coban, Basak; Yildiz, Ahu Arslan; Yildiz, Umit Hakan
    This study describes the formation of single-chain polymer dots (Pdots) via ultrasonic emulsification of nonionic donor-acceptor-donor type (D-A-D) alkoxy thiophene-benzobisthiadiazole-based conjugated polymers (Poly BT) with amphiphilic cetyltrimethylammonium bromide (CTAB). The methodology yields Pdots with a high cationic surface charge (+56.5 mV +/- 9.5) and average hydrodynamic radius of 12 nm. Optical characterization reveals that these Pdots emit near-infrared (NIR) light at a maximum wavelength of 860 nm owing to their conjugated polymer backbone consisting of D-A-D monomers. Both colloidal and optical properties of these Pdots make them promising fluorescence emissive probes for bioimaging applications. The significant advantage of positively charged Pdots is demonstrated in diffusion-limited mediums such as tissues, utilizing human epithelial breast adenocarcinoma, ATCC HTB-22 (MCF-7), human bone marrow neuroblastoma, ATCC CRL-2266 (SH-SY5Y), and rat adrenal gland pheochromocytoma, CRL-1721 (PC-12) tumor spheroid models. Fluorescence microscopy analysis of tumor spheroids from MCF-7, SH-SY5Y, and PC-12 cell lines reveals the intensity profile of Pdots, confirming extensive penetration into the central regions of the models. Moreover, a comparison with mitochondria staining dye reveals an overlap between the regions stained by Pdots and the dye in all three tumor spheroid models. These results suggest that single-chain D-A-D type Pdots, cationized via CTAB, exhibit long-range mean free path of penetration (approximate to 1 mu m) in dense mediums and tumors. The single chain near infrared (NIR) emissive Pdots with high cationic surface charge enable penetration in dense medium such as tumor spheroids. Both colloidal and optical properties of Pdots make them promising fluorescent probe in bioimaging. image
  • Article
    Citation - WoS: 10
    Citation - Scopus: 9
    Exploring Neuronal Differentiation Profiles in Sh-Sy5y Cells Through Magnetic Levitation Analysis
    (Amer Chemical Soc, 2024) Kartal, Rumeysa Bilginer; Yildiz, Ahu Arslan
    Magnetic levitation (MagLev) is a powerful and versatile technique that can sort objects based on their density differences. This paper reports the sorting of SH-SY5Y cells for neuronal differentiation by the MagLev technique. Herein, SH-SY5Y cells were differentiated with retinoic acid (RA) and brain-derived neurotrophic factor (BDNF). Neuronal differentiation was confirmed by neurite extension measurement and the immunostaining assay. Neurites reached the maximum length on day 9 after sequential treatment with RA-BDNF. Neuronal marker expression of un-/differentiated cells was investigated by beta-III tubulin and neuronal nuclei (NeuN) and differentiated cells exhibited a higher fluorescence intensity compared to un-/differentiated cells. MagLev results revealed that the density of differentiated SH-SY5Y cells gradually increased from 1.04 to 1.06 g/mL, while it remained stable at 1.05 g/mL for un-/differentiated cells. These findings signified that cell density would be a potent indicator of neuronal differentiation. Overall, it was shown that MagLev methodology can provide rapid, label-free, and easy sorting to analyze the differentiation of cells at a single-cell level.
  • Conference Object
    Düşük Sükroz Derişimlerinin Görünür Bölge Spektroskopisi ve Yapay Sinir Aǧları ile Kestirimi
    (IEEE, 2017) Mezgil, Bahadir; Erdogan, Duygu; Alduran, Yesim; Yildiz, Umit Hakan; Yildiz, Ahu Arslan; Bastanlar, Yahn
    Low sucrose concentrations in solutions is estimated by means of localized surface plasmon resonance of immobilized gold nanoparticles. The ultraviolet-visible spectra (UV-Vis) of samples with different sucrose concentrations were prepared and used to train artificial neural networks. In our study, MATLAB Neural Networks Toolbox was used and effect of different input sizes and network structures on the estimation accuracy is investigated. It is observed that using complete spectrum instead of peak point results in higher accuracy.