Ultrasmall bimodal nanomolecules enhanced tumor angiogenesis contrast with endothelial cell targeting and molecular pharmacokinetics.

Nonintrusive and precise imaging for tumor angiogenesis is critical in accurate assessment of cancer diagnosis and prognosis. However, reticulo-endothelial system (RES) capture and inadequate accumulation remain major bottlenecks for current nanoparticle to retain at tumor angiogenesis site. Herein, we report the ultrasmall contrast agent (cNGR-Au:Gd@GSH NMs) could accumulate at tumor vasculature site and enhance the tumor angiogenesis-contrast. It is demonstrated that by loading Au and Gd atom into the naturally-occurring glutathione (GSH) shell with cNGR peptide modification, cNGR-Au:Gd@GSH NMs exhibit the high X-ray photon absorption, longer rotational correlation time and efficient tumor vascular endothelia cell targeting. In vivo studies further indicate the cNGR-Au:Gd@GSH NMs prominently enhance tumor angiogenesis-contrast both on the computed tomography (CT) and magnetic resonance imaging (MRI) modalities by escaping the RES capture and target delivering. Our data imply that the cNGR-Au:Gd@GSH NMs may serve as the high-efficiency contrast agent to assess tumor angiogenesis in a nonintrusive technique.