Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
Browse
3 results
Search Results
Article Citation - WoS: 31Citation - Scopus: 32Synthesis and Characterization of Chitosan-Vermiculite Composite Beads for Removal of Uranyl Ions: Isotherm, Kinetics and Thermodynamics Studies(Springer, 2020-11-19) Senol, Zeynep Mine; Simsek, Selcuk; Ozer, Ali; Senol Arslan, DilekIn this study, a new material containing Chitosan (Ch)-Vermiculite (V) composite beads was synthesized with epichlorohydrin cross-linking agent and used to remove uranyl ions from the aqueous solution. The prepared new material was characterized by SEM, XRD, FTIR analyses and PZC measurement. The effects of significant parameters on adsorption including temperature, pH, concentration and time were investigated. The obtained results indicated that the new composites of Ch-V was revealed in different structure. The zeta potential analyses showed that electrostatic attraction existed during the adsorption process between the uranyl ions and Ch-V. The maximum adsorption capacity of material was calculated as 0.665 mol kg(-1) by considering Langmuir equation. Adsorption kinetic was also explained with pseudo second order and intra particular diffusion models. Experimental studies clearly showed that the adsorption was endothermic and occurred spontaneously. The newly developed smart material has many advantages such as reusability, high adsorption capacity, selectivity and economics.Article Citation - WoS: 13Citation - Scopus: 15Prevention of Cisplatin-Induced Nephrotoxicity by Kidney-Targeted siRNA Delivery(Elsevier, 2022-11) Aydin, Erkin; Cebeci, Aysun; Lekesizcan, AycaCisplatin is a potent and widely used chemotherapy agent, however, nephrotoxicity limits its use. Many patients need to pause or withdraw from chemotherapy to prevent acute kidney injury. To prevent cisplatin damage, we designed chitosan/siRNA nanoparticleswhich are nontoxic and are readily taken up by HEK293 cells. The nanoparticles contained siRNA against cationic membrane transport (OCT1&2) and apoptosis related proteins (p53, PKC8, and gamma GT). In mice treated with cisplatin, serum creatinine levels increased from 15 to 88 mg/dL and blood urea nitrogen levels increased from 0.25 to 1.7 mg/dL, however, siRNA nanoparticles significantly limited these levels to 30 mg/dL and 0.55 mg/dL, respectively. Western and IHC analyses showed lower p53, PKC8, and gamma GT expressions in siRNA treated mice. Histomorphological evaluation revealed high-level protection of kidney proximal tubules from cisplatin damage. Protein expressions and extent of kidney protection were directly correlated with number of siRNA applications. Our results suggest that this novel approach for kidney -targeted delivery of select siRNAs may represent a promising therapy for preventing cisplatin-induced nephro-toxicity. Furthermore, this or other similarly sized nanocarriers could potentially be utilized to passively target kidneys for diagnostic, protective, or treatment purposes.Article Citation - WoS: 14Citation - Scopus: 14Isotherms, Kinetics and Thermodynamics of Pb(II) Adsorption by Crosslinked Chitosan/Sepiolite Composite(Springer, 2021-04-13) Senol-Arslan, DilekA novel composite adsorbent was prepared from chitosan (Ch) and sepiolite (S) for removal of Pb(II) from aqueous solution. The Ch-S composite beads were successfully synthesized by crosslinking epichlorohydrin (ECH) and tripolyphosphate (NaTPP). A number of physicochemical parameters such as, pH, initial Pb(II) concentration, temperature, contact time and desorption have been studied during the adsorption process. Experimental data acquired from batch adsorption tests have been analyzed by three isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich), and three kinetic models including the pseudo-first-order, the pseudo-second-order and intraparticle diffusion equations using nonlinear regression technique. Langmuir isotherm was the best to fit the experimental data (R-2 = 0.971). The maximum adsorption capacity was 0.158 mol kg(-1) from Langmuir isotherm model. Maximum removal efficiency was found approximately 66% for the initial Pb(II) concentration of 1000 mg/L, adsorbent dosage of 100 mg and agitation speed of 150 rpm at pH 4.5. The adsorption free energy was found as E-DR (15.8 kJ mol(-1)), which indicated that Pb(II) adsorption process onto Ch-S composite was chemically performed. The kinetic studies have shown that the best fitted kinetic model is the pseudo-first order (R-2 = 0.979). Adsorption enthalpy value was determined as 18.7 kJ mol(-1), adsorption entropy was found as 106 J mol(-1) K-1, and Gibbs free energy was found as 12.9 kJ mol(-1). The thermodynamic parameters showed that the adsorption of Pb(II) on Ch-S was endothermic, possible and spontaneous.