title: Silica-encapsulated magnetic nanoparticles: enzyme immobilization and cytotoxic study.
abstract: Silica-encapsulated magnetic nanoparticles (MNPs) were prepared via microemulsion method. The products were characterized by high resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectrum (EDS). MNPs with no observed cytotoxic activity against human lung carcinoma cell and brine shrimp lethality were used as suitable support for glucose oxidase (GOD) immobilization. Binding of GOD onto the support was confirmed by the FTIR spectra. The amount of immobilized GODs was 95 mg/g. Storage stability study showed that the immobilized GOD retained 98% of its initial activity after 45 days and 90% of the activity was also remained after 12 repeated uses. Considerable enhancements in thermal stabilities were observed for the immobilized GOD at elevated temperatures up to 80°C and the activity of immobilized enzyme was less sensitive to pH changes in solution.
authors.affiliation: Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran.
authors.forename: Khadijeh
authors.initials: K
authors.lastname: Ashtari
authors.forename: Khosro
authors.initials: K
authors.lastname: Khajeh
authors.forename: Javad
authors.initials: J
authors.lastname: Fasihi
authors.forename: Parviz
authors.initials: P
authors.lastname: Ashtari
authors.forename: Ali
authors.initials: A
authors.lastname: Ramazani
authors.forename: Hojatollah
authors.initials: H
authors.lastname: Vali
mesh_terms: D000818:Animals; D002214:Capsules; D002417:Cattle; D045744:Cell Line, Tumor; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D059346:Magnets / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D002214:Capsules; D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D005949:Glucose Oxidase