Multitheragnostic Multi-GNRs Crystal-Seeded Magnetic Nanoseaurchin for Enhanced In Vivo Mesenchymal-Stem-Cell Homing, Multimodal Imaging, and Stroke Therapy

A multifunctional nanoseaurchin probe in which mesoporous silica nanobeads with iron oxide nanoparticles embedded and multi‐gold nanorods crystal‐seeded are fabricated and labeled with umbilical cord mesenchymal stem cells through endocytosis. This nanoplatform enables efficient magnetic remote‐controlled guiding for stem cell homing, and provides dual modalities of photoacoustic imaging and magnetic resonance imaging for in situ tracking and long‐term monitoring to achieve therapeutic efficacy.