3
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      A new catechol-functionalized polyamidoamine as an effective SPION stabilizer.

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          A synthetic strategy was established for decorating and stabilizing superparamagnetic iron oxide nanoparticles (SPIONs) with a zwitterionic linear polyamidoamine (PAA). The strategy was successfully tested with a PAA coded ISA23 previously found endowed with interesting biological properties, such as biocompatibility, degradability in aqueous media and stealth-like properties when injected in test animals. A post-synthetic functionalization with catechol-bearing moieties of a preformed PAA was successfully carried out. ISA23 was obtained by polyaddition reactions of methyl-piperazine and 2,2-bis(acrylamidoacetic) acid. It was functionalized using nitrodopamine and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide as coupling agent, to randomly form amide bonds with 17% of ISA23 carboxylic groups (ISA23-ND). SPIONs were prepared by a thermal decomposition synthesis in 1-octadecene with oleic acid, and then transferred in water by two distinct ligand exchange procedures: i) the direct displacement of oleate molecules from SPION surface by ISA23 in a biphasic (n-hexane/water) environment; ii) the two-step method involving an intermediate small molecule, tetramethylammonium hydroxide, used as a transient transfer agent, which was in turn exchanged with ISA23-ND in a second exchange step occurring in water. The two-step procedure provided a SPION@PAA nanocomposite more stable than that obtained by the one-step procedure in the presence of an applied external magnetic field. ATR-FTIR spectroscopy, ζ-potential and thermogravimetric analysis (TGA) showed the presence of the ISA23 on the SPION surface. In particular, TGA showed that the ISA23-ND amount on the NPs accounted for 26% of the overall nanocomposite mass. The nanocomposite size was determined by both TEM (21.1±2.9 nm) and DLS measurements (hydrodynamic size 100±28 nm). SPION@ISA23-ND were re-suspended after lyophilization reverting to their pristine dimensions. The SPION@ISA23-ND adsorption of BSA in water, considered as the first stage of phagocytosis, was very low, suggesting that ISA23 could impart stealthiness to SPION@ISA23-ND. 1H-NMR relaxivity measurements showed an r2 value of 158 s-1 mmol-1 L (vs 100 s-1 mmol-1L for Endorem®) at relevant clinical fields for magnetic resonance imaging (from 0.2 to 1.5 T). SPION@ISA23-ND was tested on HeLa cells and their internalization was visualized by reflectance microscopy. Finally, with the aim of prepare a new dual magneto-optical system, a synthetic procedure to decorate SPION@ISA23-ND with a fluorescent dye was devised, even though the emission intensity of the resultant conjugate was lower than expected, possibly due to luminescence quenching caused by the closeness of emitting moieties to the SPION surface.

          Related collections

          Author and article information

          Journal
          Colloids Surf B Biointerfaces
          Colloids and surfaces. B, Biointerfaces
          Elsevier BV
          1873-4367
          0927-7765
          Feb 01 2019
          : 174
          Affiliations
          [1 ] Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy.
          [2 ] Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy; Consorzio INSTM, via G. Giusti 9, 50121, Firenze, Italy.
          [3 ] Laboratorio di Nanotecnologie, CNR-Istituto di Scienze e Tecnologie Molecolari, Via G. Fantoli 16/15 I, 20138 Milano, Italy.
          [4 ] Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy; Istituto per lo studio delle macromolecole, Consiglio Nazionale delle Ricerche (ISMAC-CNR), Via A. Corti 12, 20133 Milano, Italy.
          [5 ] Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy; Consorzio INSTM, via G. Giusti 9, 50121, Firenze, Italy.
          [6 ] Groningen Research Institute of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, the Netherlands.
          [7 ] Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy; Consorzio INSTM, via G. Giusti 9, 50121, Firenze, Italy. Electronic address: daniela.maggioni@unimi.it.
          Article
          S0927-7765(18)30783-5
          10.1016/j.colsurfb.2018.11.007
          30469047
          fcdaa1c7-c426-473f-a0b2-ce9ab07a9c62
          Copyright © 2018 Elsevier B.V. All rights reserved.
          History

          Ligand exchange,Polyamidoamine,Relaxivity,SPION
          Ligand exchange, Polyamidoamine, Relaxivity, SPION

          Comments

          Comment on this article