Magnetic Nanoclusters Coated with Albumin, Casein, and Gelatin: Size Tuning, Relaxivity, Stability, Protein Corona, and Application in Nuclear Magnetic Resonance Immunoassay
Pavel Khramtsov,
Irina Barkina,
Maria Kropaneva,
Maria Bochkova,
Valeria Timganova,
Anton Nechaev,
Il’ya Byzov,
Svetlana Zamorina,
Anatoly Yermakov,
Mikhail Rayev
Affiliations
Pavel Khramtsov
Laboratory of Ecological Immunology, Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Branch of PSRC UB RAS, 13 Golev str., 614081 Perm, Russia
Irina Barkina
Department of Microbiology and Immunology, Biology Faculty, Perm State National Research University, 15 Bukirev str., 614000 Perm, Russia
Maria Kropaneva
Laboratory of Ecological Immunology, Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Branch of PSRC UB RAS, 13 Golev str., 614081 Perm, Russia
Maria Bochkova
Laboratory of Ecological Immunology, Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Branch of PSRC UB RAS, 13 Golev str., 614081 Perm, Russia
Valeria Timganova
Laboratory of Ecological Immunology, Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Branch of PSRC UB RAS, 13 Golev str., 614081 Perm, Russia
Anton Nechaev
Institute of Technical Chemistry of Ural Branch of the RAS, 3 Academician Korolev str., 614013 Perm, Russia
Il’ya Byzov
Laboratory of Ecological Immunology, Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Branch of PSRC UB RAS, 13 Golev str., 614081 Perm, Russia
Svetlana Zamorina
Laboratory of Ecological Immunology, Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Branch of PSRC UB RAS, 13 Golev str., 614081 Perm, Russia
Anatoly Yermakov
Laboratory of Ecological Immunology, Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Branch of PSRC UB RAS, 13 Golev str., 614081 Perm, Russia
Mikhail Rayev
Laboratory of Ecological Immunology, Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Branch of PSRC UB RAS, 13 Golev str., 614081 Perm, Russia
The surface functionalization of magnetic nanoparticles improves their physicochemical properties and applicability in biomedicine. Natural polymers, including proteins, are prospective coatings capable of increasing the stability, biocompatibility, and transverse relaxivity (r2) of magnetic nanoparticles. In this work, we functionalized the nanoclusters of carbon-coated iron nanoparticles with four proteins: bovine serum albumin, casein, and gelatins A and B, and we conducted a comprehensive comparative study of their properties essential to applications in biosensing. First, we examined the influence of environmental parameters on the size of prepared nanoclusters and synthesized protein-coated nanoclusters with a tunable size. Second, we showed that protein coating does not significantly influence the r2 relaxivity of clustered nanoparticles; however, the uniform distribution of individual nanoparticles inside the protein coating facilitates increased relaxivity. Third, we demonstrated the applicability of the obtained nanoclusters in biosensing by the development of a nuclear-magnetic-resonance-based immunoassay for the quantification of antibodies against tetanus toxoid. Fourth, the protein coronas of nanoclusters were studied using SDS-PAGE and Bradford protein assay. Finally, we compared the colloidal stability at various pH values and ionic strengths and in relevant complex media (i.e., blood serum, plasma, milk, juice, beer, and red wine), as well as the heat stability, resistance to proteolytic digestion, and shelf-life of protein-coated nanoclusters.
