Preparation of yttrium-90 resin microspheres based on SiO2-Fe3O4 nanomaterials and analysis of their biodistribution

Abstract

This study reports the development and evaluation of yttrium-90 (90Y) radiolabeled silica-coated iron oxide (SiO2-Fe3O4) resin microspheres for potential theranostic application in cancer radiation therapy. Iron oxide nanoparticles of average diameter 29.7 nm were synthesized via optimized co-precipitation and displayed superparamagnetic behavior ideal for MRI. Aminosilane surface functionalization enabled covalent conjugation of 1 mmol/g DTPA/DOTA chelators for labeling 2 mCi 90Y per 150 μg nanoparticles with 92 % efficiency when incubated for 45 mins at pH 5.5 and 50°C. In vitro stability assays in buffers and human serum showed excellent 90Y retention (>95 %) up to 48 hours. In vivo biodistribution in Wistar rats revealed extended nanoparticle circulation half-life of 5.2 hours and peak exposure of 22.4 %ID/g compared to rapid clearance of unconjugated 90Y chloride within 1 hour. Complete renal recovery by 72 hours and minimal bone accumulation (<2 %) proves in vivo stability and biocompatibility of the 90Y-radiolabeled theranostic platform.

Keywords

• Theranostics
• Radiotherapy
• Circulation
• Chelation
• Biocompatibility