title: Design of a multi-dopamine-modified polymer ligand optimally suited for interfacing magnetic nanoparticles with biological systems.
abstract: We have designed a set of multifunctional and multicoordinating polymer ligands that are optimally suited for surface functionalizing iron oxide and potentially other magnetic nanoparticles (NPs) and promoting their integration into biological systems. The amphiphilic polymers are prepared by coupling (via nucleophilic addition) several amine-terminated dopamine anchoring groups, poly(ethylene glycol) moieties, and reactive groups onto a poly(isobutylene-alt-maleic anhydride) (PIMA) chain. This design greatly benefits from the highly efficient and reagent-free one-step reaction of maleic anhydride groups with amine-containing molecules. The availability of several dopamine groups in the same ligand greatly enhances the ligand affinity, via multiple coordination, to the magnetic NPs, while the hydrophilic and reactive groups promote colloidal stability in buffer media and allow subsequent conjugation with target biomolecules. Iron oxide nanoparticles ligand exchanged with these polymer ligands have a compact hydrodynamic size and exhibit enhanced long-term colloidal stability over the pH range of 4-12 and in the presence of excess electrolytes. Nanoparticles ligated with terminally reactive polymers have been easily coupled to target dyes and tested in live cell imaging with no measurable cytotoxicity. Finally, the resulting hydrophilic nanoparticles exhibit large and size-dependent r2 relaxivity values.
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University , 95 Chieftan Way, Tallahassee, Florida 32306, United States.
authors.forename: Wentao
authors.initials: W
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Ji
authors.forename: Hyon Bin
authors.initials: HB
authors.lastname: Na
authors.forename: Malak
authors.initials: M
authors.lastname: Safi
authors.forename: Alexandra
authors.initials: A
authors.lastname: Smith
authors.forename: Goutam
authors.initials: G
authors.lastname: Palui
authors.forename: J Manuel
authors.initials: JM
authors.lastname: Perez
authors.forename: Hedi
authors.initials: H
authors.lastname: Mattoussi
mesh_terms: D000577:Amides / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D002470:Cell Survival; D003102:Colloids / Q000737:chemistry*; D003287:Contrast Media / Q000737:chemistry; D004573:Electrolytes; D005290:Ferric Compounds / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D057446:Hydrodynamics; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D008027:Light; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D008299:Maleic Anhydrides / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011193:Potassium Iodide / Q000737:chemistry; D012542:Scattering, Radiation
chemical_list: D000577:Amides; D000588:Amines; D003102:Colloids; D003287:Contrast Media; D004573:Electrolytes; D005290:Ferric Compounds; D008024:Ligands; D008299:Maleic Anhydrides; D011108:Polymers; D011193:Potassium Iodide; C000499:ferric oxide