SpyCatcher-Engineered Ferritin Nanocages Enable Dual-Receptor Targeting for Enhanced Glioma Therapy

Human heavy-chain ferritin (FTn) that can bind to transferrin receptor 1 (TfR1) has emerged as a promising platform for brain tumor drug delivery. However, the broad expression of TfR1 in normal tissues fundamentally limits tumor selectivity and therapeutic precision. Herein, we engineered a dual-receptor-targeting FTn nanoplatform by site-specifically conjugating an epidermal growth factor receptor (EGFR) affibody to FTn using the SpyCatcher/SpyTag system, generating FTn-EGFRAfb nanoparticles. This modular strategy preserves FTn architecture and stability while enabling precise ligand conjugation. Doxorubicin (DOX) was efficiently encapsulated via temperature-controlled loading to obtain DOX@FTn-EGFRAfb with high protein recovery, pH-responsive drug release, and strong stability. In vitro, the nanoparticles showed enhanced uptake and cytotoxicity in TfR1/EGFR double-positive U87 glioma cells. In an orthotopic U87 glioma mouse model, DOX@FTn-EGFRAfb significantly inhibited tumor growth and prolonged survival without obvious systemic toxicity. This work presents a versatile protein-engineering strategy for dual-targeted glioblastoma drug delivery.