High relaxivity Gd(III)-DNA gold nanostars

Investigation of shape effects on proton relaxation

Matthew W. Rotz, Kayla S B Culver, Giacomo Parigi, Keith W. Macrenaris, Claudio Luchinat, Teri W Odom, Thomas J. Meade

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Gadolinium(III) nanoconjugate contrast agents (CAs) have distinct advantages over their small-molecule counterparts in magnetic resonance imaging. In addition to increased Gd(III) payload, a significant improvement in proton relaxation efficiency, or relaxivity (r1), is often observed. In this work, we describe the synthesis and characterization of a nanoconjugate CA created by covalent attachment of Gd(III) to thiolated DNA (Gd(III)-DNA), followed by surface conjugation onto gold nanostars (DNA-Gd@stars). These conjugates exhibit remarkable r1 with values up to 98 mM-1 s-1. Additionally, DNA-Gd@stars show efficient Gd(III) delivery and biocompatibility in vitro and generate significant contrast enhancement when imaged at 7 T. Using nuclear magnetic relaxation dispersion analysis, we attribute the high performance of the DNA-Gd@stars to an increased contribution of second-sphere relaxivity compared to that of spherical CA equivalents (DNA-Gd@spheres). Importantly, the surface of the gold nanostar contains Gd(III)-DNA in regions of positive, negative, and neutral curvature. We hypothesize that the proton relaxation enhancement observed results from the presence of a unique hydrophilic environment produced by Gd(III)-DNA in these regions, which allows second-sphere water molecules to remain adjacent to Gd(III) ions for up to 10 times longer than diffusion. These results establish that particle shape and second-sphere relaxivity are important considerations in the design of Gd(III) nanoconjugate CAs.

Original languageEnglish
Pages (from-to)3385-3396
Number of pages12
JournalACS Nano
Volume9
Issue number3
DOIs
Publication statusPublished - Mar 24 2015

Fingerprint

Gold
Protons
DNA
deoxyribonucleic acid
Nanoconjugates
gold
protons
Contrast Media
Stars
stars
Magnetic relaxation
Molecules
augmentation
Gadolinium
magnetic relaxation
biocompatibility
Magnetic resonance
gadolinium
conjugation
Biocompatibility

Keywords

  • contrast agent
  • gadolinium
  • magnetic resonance
  • nanostar
  • nuclear magnetic resonance dispersion
  • relaxivity
  • second-sphere

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

Cite this

Rotz, M. W., Culver, K. S. B., Parigi, G., Macrenaris, K. W., Luchinat, C., Odom, T. W., & Meade, T. J. (2015). High relaxivity Gd(III)-DNA gold nanostars: Investigation of shape effects on proton relaxation. ACS Nano, 9(3), 3385-3396. https://doi.org/10.1021/nn5070953

High relaxivity Gd(III)-DNA gold nanostars : Investigation of shape effects on proton relaxation. / Rotz, Matthew W.; Culver, Kayla S B; Parigi, Giacomo; Macrenaris, Keith W.; Luchinat, Claudio; Odom, Teri W; Meade, Thomas J.

In: ACS Nano, Vol. 9, No. 3, 24.03.2015, p. 3385-3396.

Research output: Contribution to journalArticle

Rotz, MW, Culver, KSB, Parigi, G, Macrenaris, KW, Luchinat, C, Odom, TW & Meade, TJ 2015, 'High relaxivity Gd(III)-DNA gold nanostars: Investigation of shape effects on proton relaxation', ACS Nano, vol. 9, no. 3, pp. 3385-3396. https://doi.org/10.1021/nn5070953
Rotz, Matthew W. ; Culver, Kayla S B ; Parigi, Giacomo ; Macrenaris, Keith W. ; Luchinat, Claudio ; Odom, Teri W ; Meade, Thomas J. / High relaxivity Gd(III)-DNA gold nanostars : Investigation of shape effects on proton relaxation. In: ACS Nano. 2015 ; Vol. 9, No. 3. pp. 3385-3396.
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