title: Biophysical interactions of polyamidoamine dendrimer coordinated Fe3O4 nanoparticles with insulin.
abstract: Advanced delivery systems, such as nano/micro carriers have not been studied significantly for their molecular interactions with serum proteins and other biologically relevant macromolecules. Here, we investigated the effect of surface chemistry of iron oxide (Fe3O4) nanoparticles on molecular interactions with human insulin by fluorescence, XRD and FTIR spectroscopy. Nanoparticles of Fe3O4 were chemically modified as Fe3O4-glutathione (GSH) and Fe3O4-GSH-polyamidoamine generation 4 (PAMAM G4) dendrimer. Our results demonstrate that, Fe3O4 and its conjugates such as Fe3O4-GSH, Fe3O4-GSH-G4 quenched insulin fluorescence, indicating strong interactions between insulin protein molecule and Fe3O4. The fluorescence quenching constants Ksv were obtained as 0.0367 x 10(3), 0.0303 x 10(3) and 0.0131 x 10(3) M and the binding constant K were found to be 27.095, 8.404 and 6.026 mM for Fe3O4, Fe3O4-GSH and Fe3O4-GSH-PAMAM G4, respectively. Both the Ksv and K (binding constant) values revealed that the interaction of Fe3O4 with insulin to be stronger over to dendrimer conjugates. In addition, the FTIR spectra suggested that the presence of nanoparticles results in secondary structure alteration in the insulin conformation. The study implies the critical evaluation of new delivery systems in establishing the biocompatibility, especially when delivered by systemic route.
authors.forename: Mayuri
authors.initials: M
authors.lastname: Samant
authors.forename: Shashwat S
authors.initials: SS
authors.lastname: Banerjee
authors.forename: Neetika
authors.initials: N
authors.lastname: Taneja
authors.forename: Khushbu
authors.initials: K
authors.lastname: Zope
authors.forename: Preetam
authors.initials: P
authors.lastname: Ghogale
authors.forename: Jayant J
authors.initials: JJ
authors.lastname: Khandare
mesh_terms: D055592:Biophysical Phenomena; D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry*; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D005978:Glutathione / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009757:Nylons / Q000138:chemical synthesis / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D050091:Dendrimers; D005290:Ferric Compounds; D007328:Insulin; D009757:Nylons; C520550:PAMAM-G4; C000499:ferric oxide; D005978:Glutathione