title: Bio-inspired, melanin-like nanoparticles as a highly efficient contrast agent for T1-weighted magnetic resonance imaging.
abstract: The development of nontoxic and biocompatible imaging agents will create new opportunities for potential applications in clinical MRI diagnosis. Synthetic melanin-like nanoparticles (MelNPs), analogous to natural sepia melanin (a major component of the cuttlefish ink), can be used as contrast agent for MRI. MelNPs complexed with paramagnetic Fe(3+) ions show much higher relaxivity values than existing MRI T1 contrast agents based on gadolinium (Gd) or manganese (Mn); MelNP values at 3T were r1 = 17 and r2 = 18 mM(-1) s(-1) (r2/r1 value of 1.1). With significant enhancement to MRI contrast, this biomimetic approach using MelNPs functionalized with paramagnetic Fe(3+) ions and surface-modified with biocompatible poly(ethylene glycol) units, could provide new insight into how melanin-based bioresponsive and therapeutic imaging probes integrate with their various biological functions.
authors.affiliation: Department of Chemistry and ∥Department of Biophysics and Chemical Biology and Bio-MAX Institute, Seoul National University , Seoul 151-747, Korea.
authors.forename: Kuk-Youn
authors.initials: KY
authors.lastname: Ju
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Geun Ho
authors.initials: GH
authors.lastname: Im
authors.forename: Sanghee
authors.initials: S
authors.lastname: Lee
authors.forename: Jung
authors.initials: J
authors.lastname: Pyo
authors.forename: Seung Bum
authors.initials: SB
authors.lastname: Park
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Lee
authors.forename: Jin-Kyu
authors.initials: JK
authors.lastname: Lee
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D003287:Contrast Media / Q000737:chemistry / Q000494:pharmacology; D049832:Decapodiformes; D004305:Dose-Response Relationship, Drug; D006367:HeLa Cells; D006801:Humans; D007281:Ink; D008279:Magnetic Resonance Imaging; D008543:Melanins / Q000737:chemistry*; D051379:Mice; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013499:Surface Properties; D014018:Tissue Distribution
chemical_list: D001672:Biocompatible Materials; D003287:Contrast Media; D008543:Melanins; D011092:Polyethylene Glycols