title: Functionalized SPIONs: the surfactant nature modulates the self-assembly and cluster formation.
abstract: SuperParamagnetic Iron Oxide Nanoparticles (SPIONs) represent a suitable system for several applications especially in nanomedicine. Great efforts have been made to design stable and biocompatible functionalized SPIONs suitable for diagnostics and drug delivery. In particular, zwitterionic-surfactant functionalized SPIONs, obtained through a coating strategy based on hydrophobic interaction, are promising systems for biomedical applications. The size of functionalized SPIONs has emerged as a crucial parameter determining their fate in living organisms. However, not all the proposed functionalization strategies lead to monodispersed systems and SPION clustering often occurs. In this study, we report a systematic investigation on different surfactant-functionalized SPIONs in order to explore the possibility of tuning the particle size by choosing an appropriate amphiphilic molecule. By combining Small-Angle Neutron Scattering (SANS) and Dynamic Light Scattering (DLS) analysis, we have provided a detailed description of the functionalized SPION structure. Furthermore, we have also related the surfactant aggregation properties, i.e. the Critical Micelle Concentration (CMC), to their efficiency in coating the SPION surface. A lack in the formation of a compact shell leads to a clusters formation. On this basis, the present study contributes to furnishing decisive information to define synthetic strategies able to tune functionalized-SPION design.
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario di Monte S. Angelo, via Cintia 4, 80126 Naples, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Luchini
authors.forename: Richard K
authors.initials: RK
authors.lastname: Heenan
authors.forename: Luigi
authors.initials: L
authors.lastname: Paduano
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vitiello
mesh_terms: D016503:Drug Delivery Systems; D000067493:Dynamic Light Scattering; D005290:Ferric Compounds / Q000737:chemistry*; D008823:Micelles; D050997:Nanomedicine; D010316:Particle Size; D011663:Pulmonary Surfactants / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D008823:Micelles; D011663:Pulmonary Surfactants; D013501:Surface-Active Agents; C000499:ferric oxide