Enhanced MRI T 2 Relaxivity in Contrast-Probed Anchor-Free PEGylated Iron Oxide Nanoparticles

Autor: Bibek Thapa, Daysi Diaz-Diestra, Juan Beltran-Huarac, Brad R. Weiner, Gerardo Morell
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Nanoscale Research Letters, Vol 12, Iss 1, Pp 1-13 (2017)
Druh dokumentu: article
ISSN: 1931-7573
1556-276X
DOI: 10.1186/s11671-017-2084-y
Popis: Abstract Superparamagnetic iron oxide nanoparticles (SPIONs, ~11-nm cores) were PEGylated without anchoring groups and studied as efficient MRI T 2 contrast agents (CAs). The ether group of PEG is efficiently and directly linked to the positively charged surface of SPIONs, and mediated through a dipole-cation covalent interaction. Anchor-free PEG-SPIONs exhibit a spin-spin relaxivity of 123 ± 6 mM−1s−1, which is higher than those of PEG-SPIONs anchored with intermediate biomolecules, iron oxide nanoworms, or Feridex. They do not induce a toxic response for Fe concentrations below 2.5 mM, as tested on four different cell lines with and without an external magnetic field. Magnetic resonance phantom imaging studies show that anchor-free PEG-SPIONs produce a significant contrast in the range of 0.1–0.4 [Fe] mM. Our findings reveal that the PEG molecules attached to the cores immobilize water molecules in large regions of ~85 nm, which would lead to blood half-life of a few tens of minutes. This piece of research represents a step forward in the development of next-generation CAs for nascent-stage cancer detection. Graphical Abstract Contrast-probed anchor-free PEGylated iron oxide contrast agent
Databáze: Directory of Open Access Journals
Externí odkaz: