title: Tuning the non-covalent confinement of Gd(III) complexes in silica nanoparticles for high T1-weighted MR imaging capability.
abstract: The present work introduces deliberate synthesis of Gd(III)-doped silica nanoparticles with high relaxivity at magnetic field strengths below 1.5T. Modified microemulsion water-in-oil procedure was used in order to achieve superficial localization of Gd(III) complexes within 40-55nm sized silica spheres. The relaxivities of the prepared nanoparticles were measured at 0.47, 1.41 and 1.5T with the use of both NMR analyzer and whole body NMR scanner. Longitudinal relaxivities of the obtained silica nanoparticles reveal significant dependence on the confinement mode, changing from 4.1 to 49.6mM-1s-1at 0.47T when the localization of Gd(III) complexes changes from core to superficial zones of the silica spheres. The results highlight predominant contribution of the complexes located close to silica/water interface to the relaxivity of the nanoparticles. Low effect of blood proteins on the relaxivity in the aqueous colloids of the nanoparticles was exemplified by serum bovine albumin. T1- weighted MRI data indicate that the nanoparticles provide strong positive contrast at 1.5T, which along with low cytotoxicity effect make a good basis for their application as contrast agents.
authors: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia.
authors: Svetlana V
authors: SV
authors: Fedorenko
authors: Kazan (Volga region) Federal university, Kremlyovskaya str., 18, 420008, Kazan, Russia.
authors: Svetlana L
authors: SL
authors: Grechkina
authors: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia.
authors: Asiya R
authors: AR
authors: Mustafina
authors: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia.
authors: Kirill V
authors: KV
authors: Kholin
authors: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia; Kazan (Volga region) Federal university, Kremlyovskaya str., 18, 420008, Kazan, Russia. Electronic address: aleksestepanov@yandex.ru.
authors: Alexey S
authors: AS
authors: Stepanov
authors: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia; Kazan National Research Technological University, Kazan 420015, Russia.
authors: Irek R
authors: IR
authors: Nizameev
authors: A.N. Tupolev Kazan National Research Technical University, 10, K. Marx St., Kazan, 420111, Russia.
authors: Ildus E
authors: IE
authors: Ismaev
authors: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia.
authors: Marsil K
authors: MK
authors: Kadirov
authors: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia; Kazan (Volga region) Federal university, Kremlyovskaya str., 18, 420008, Kazan, Russia.
authors: Rustem R
authors: RR
authors: Zairov
authors: Kazan (Volga region) Federal university, Kremlyovskaya str., 18, 420008, Kazan, Russia.
authors: Alfia N
authors: AN
authors: Fattakhova
authors: Kazan (Volga region) Federal university, Kremlyovskaya str., 18, 420008, Kazan, Russia.
authors: Rustem R
authors: RR
authors: Amirov
authors: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia.
authors: Svetlana E
authors: SE
authors: Soloveva
mesh_terms: D000818:Animals; D047250:Calixarenes / Q000737:chemistry*; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D003287:Contrast Media / Q000138:chemical synthesis* / Q000494:pharmacology; D005682:Gadolinium / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D053758:Nanoparticles / Q000737:chemistry; D061251:Primary Cell Culture; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D012821:Silanes; D047250:Calixarenes; D012710:Serum Albumin, Bovine; C040733:tetraethoxysilane; D012822:Silicon Dioxide; D005682:Gadolinium
keywords: Cytotoxicity; Gd(III) complexes; Interfaces; MRI; Positive contrast agents; Silica nanoparticles