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: 1Citation - Scopus: 1Structural and Functional Tuning of ZIF-8 Nanoparticles Via Zinc Salt Variation and Ligand Ratio for Enhanced Drug Delivery(Springer, 2025) Mete, Derya; Şanlı Mohamed, Gülşah; 01. Izmir Institute of Technology; 04. Faculty of Science; 04.01. Department of ChemistryThe clinical application of doxorubicin (DOX), a widely used chemotherapeutic agent, is limited by systemic toxicity, rapid clearance, and the development of multidrug resistance. Metal-organic frameworks (MOFs), particularly zeolitic imidazolate frameworks (ZIFs), have emerged as promising nanocarriers to overcome these limitations due to their high drug-loading capacity, pH-responsive release profiles, and favorable biocompatibility. Among them, ZIF-8 is especially attractive for its ability to selectively release drugs in acidic tumor microenvironments. However, the physicochemical and biological properties of ZIF-8 are highly sensitive to synthesis parameters, particularly the choice of zinc salt precursor and the Zn2+:ligand molar ratio. In this study, we systematically investigated the effects of four zinc salts (zinc nitrate, zinc acetate, zinc chloride, and zinc bromide) and three Zn2+:2-methylimidazole molar ratios (1:35, 1:70, and 1:200) on the synthesis, drug-loading efficiency, release behavior, and anticancer activity of DOX-loaded ZIF-8 (DOX@ZIF-8) nanoparticles. The resulting nanocarriers were characterized using scanning electron microscopy (SEM), dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDX), inductively coupled plasma optical emission spectroscopy (ICP-OES), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) surface area analysis. pH-responsive DOX release was evaluated under physiological (pH 7.4) and acidic (pH 5.0) conditions. Cytotoxicity was assessed in A549 lung cancer cells via the MTT assay. Additionally, in vitro time-lapse live-cell imaging and wound healing assays were conducted to evaluate intracellular drug uptake and cellular responses. Our findings highlight the critical influence of zinc salt selection and ligand ratio on the structure-property-function relationships of ZIF-8, providing valuable insights for the rational design of MOF-based nanocarriers in targeted cancer therapy.Article Citation - WoS: 7Citation - Scopus: 8Thermoalkalophilic Recombinant Esterase Entrapment in Chitosan/Calcium Beads and Its Characterization(Wiley, 2021) Tercan, Cisem; Şanlı Mohamed, Gülşah; Sürmeli, Yusuf; Şanlı Mohamed, Gülşah; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyBACKGROUND Esterases (EC 3.1.1.1), a class of hydrolases, degrade the ester bonds of lipids into alcohol and carboxylic acids and synthesize carboxylic ester bonds. They are used in a variety of biotechnological, industrial, environmental, and pharmaceutical applications due to their many valuable properties. Particularly, extremophilic esterases with many superior properties are of great interest for various reactions. Immobilization of enzymes may provide some advantages over free enzymes not only to improve the properties of enzymes but also to increase the reusability of biocatalyst in industrial applications. Therefore, many different immobilization applications for enzymes have been reported in various studies. To our knowledge, a thermophilic esterase has not so far been immobilized by entrapment using chitosan/calcium/alginate-blended beads. Here, we reported the immobilization of thermoalkalophilic recombinant esterase by entrapment using chitosan/calcium/alginate-blended beads, and then the entrapped esterase was characterized biochemically in details. RESULTS In the present study, a thermophilic recombinant esterase was immobilized by entrapment in chitosan/calcium/alginate-blended beads for the first time. The 0.5 mg mL(-1) purified recombinant esterase was entrapped in 1% chitosan, 2% alginate, and 0.7 M CaCl2 blended beads. The results showed that immobilization yield and entrapment efficiency of the entrapped esterase were 69.5% and 80.4%, respectively. SEM micrograph showed that the surface of the beads resembled a mesh and very compact structures. Chitosan/calcium/alginate-blended beads exhibited an 18.8% swelling ratio and had a moderate porous structure. The entrapment technique highly enhanced the thermostability of the esterase and shifted its optimum temperature from 65 to 80 degrees C. The immobilized esterase was very stable in a wide range of pH (8.5-11) displaying maximum activity at pH 9. ZnCl2 slightly increased the activity of immobilized esterase whereas several metal ions reduced the enzyme activity. When the enzyme was immobilized in chitosan/calcium/alginate-blended beads, its K-m increased about 2 times and V-max value decreased almost 1.5 times. Immobilization allowed repeated uses of the esterase having good operational stability in a continuous process. CONCLUSION The results revealed that the immobilization of a thermophilic recombinant esterase by entrapment in chitosan/calcium/alginate-blended beads exhibited considerably better compared to other immobilization processes with various entrapment strategies. (c) 2021 Society of Chemical Industry (SCI).