Water-soluble gold nanoparticles (AuNP) functionalized with a gadolinium(iii) chelate via Michael addition for use as a MRI contrast agent

Abstract

A contrast agent suitable for magnetic resonance imaging based on small, water soluble gold nanoparticles (AuNP) conjugated to over 50 Gd³⁺ chelators has been prepared by using an interfacial Michael addition in aqueous media. The resultant chelator–AuNP conjugates have been successfully characterised by ¹H NMR spectroscopy, IR spectroscopy, ICP-OES, ζ-potential analysis, TEM and MRI. T₁-weighted in vivo images of mouse kidney were obtained using the agent at 9.4 T. A preliminary in vivo experiment produced no ill effects and the clearance profile of the agent suggests it is suitable for animal testing at clinically relevant concentrations.