Facile preparation of versatile gadolinium-chelated protein nanocomposite for T1 magnetic resonance imaging-guided photodynamic and photothermal synergetic therapy

Imaging-guided photodynamic/photothermal (PDT/PTT) synergetic therapy is important in more precise and efficient cancer treatment. Herein, gadolinium-chelated porphyrin-protein composite based on gold nanorods (GNRs@BPP-Gd) was synthesized through a straightforward and environmentally friendly method. Based on the high longitudinal relaxivity (9.544 mM(-1) s(-1)), GNRs@BPP-Gd can serve as a decent T-1-weighted magnetic resonance imaging (MRI) probe to steer treatment. A relevant cellular uptake assay showed that GNRs@BPP-Gd could be internalized into cancer cells effectively with negligible cytotoxicity. Furthermore, MRI-guided PDT/PTT studies in vivo indicated that GNRs@BPP-Gd could efficiently take effect after intravenous injection, leading to almost complete ablation at the tumor site. A single treatment was conducted for comparison with the combined treatment, indicating that synergetic therapy greatly enhanced the anti-tumor effect.