Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 4Citation - Scopus: 5Near-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 HakanThis 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. imageArticle Citation - WoS: 1Citation - Scopus: 1Gadolinium and Polythiophene Functionalized Polyurea Polymer Dots as Fluoro-Magnetic Nanoprobes(MDPI, 2022) Karabacak, Soner; Palaniappan, Alagappan; Tony, Tsang Siu Hon; Edwin, Teo Hang Tong; Gulyás, Balázs; Padmanabhan, Parasuraman; Yıldız, Ümit HakanA rapid and one-pot synthesis of poly 3-thiopheneacetic acid (PTAA) functionalized pol-yurea polymer dots (Pdots) using polyethyleneimine and isophorone diisocyanate is reported. The one-pot mini-emulsion polymerization technique yielded Pdots with an average diameter of ~20 nm. The size, shape, and concentration of the surface functional groups could be controlled by al-tering the synthesis parameters such as ultrasonication time, concentration of the surfactant, and crosslinking agent, and the types of isocyanates utilized for the synthesis. Colloidal properties of Pdots were characterized using dynamic light scattering and zeta potential measurements. The spherical geometry of Pdots was confirmed by scanning electron microscopy. The Pdots were post-functionalized by 1,4,7,10 tetraazacyclododecane-1,4,7,10-tetraacetic acid for chelating gadolinium nanoparticles (Gd3+) that provide magnetic properties to the Pdots. Thus, the synthesized Pdots possess fluorescent and magnetic properties, imparted by PTAA and Gd3+, respectively. Fluorescence spectroscopy and microscopy revealed that the synthesized dual-functional Gd3+-Pdots ex-hibited detectable fluorescent signals even at lower concentrations. Magnetic levitation experiments indicated that the Gd3+-Pdots could be easily manipulated via an external magnetic field. These findings illustrate that the dua-functional Gd3+-Pdots could be potentially utilized as fluorescent reporters that can be magnetically manipulated for bioimaging applications.
