Gd‐Labeled Microparticles in MRI: In vivo Imaging of Microparticles After Intraperitoneal Injection

To visualize the biodistribution of porous silica microparticles in vivo, known ligands are used to immobilize gadolinium in the pores for use as MRI contrast agents. MRI studies with rodents show that a fraction of the microparticles administered by intraperitoneal injection passed through the kidneys by an unknown mechanism and are, surprisingly, excreted via the urine. Analysis of the urine with SEM and energy dispersive spectroscopy corroborated the MRI results. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.