Gadolinum Complex-Modified Polypyrrole Nanorods for Magnetic Resonance Imaging and Infrared Thermal Imaging-Guided Photothermal Therapy of Cancer

To improve the efficacy of therapies and reduce side effects, theranostics integrated imaging and therapy can achieve an optimized therapeutic outcome. Polypyrrole nanorods (PPy) were synthesized using a hydrothermal method and stabilized by both sodium oleate and 6-aminocaproic acid. Following modification with PEG and Gd-DTPA, the developed nanorods (PPy-PEG-Gd) were well dispersed in water and demonstrated excellent biocompatibility, high photothermal conversion efficiency (53.5%), and magnetic properties (r 1 = 4.56 mM–1 · s–1). T 1-weighted MR and photothermal imaging were integrated into the system to visualize the location of the cancer, or for real-time monitoring of photothermal therapy (PTT). Finally, PPy-PEG-Gd were successfully used as an efficient coupling agent for imaging-guided PTT in vitro and in vivo under NIR laser irradiation. Therefore, PPy-PEG-Gd has great potential for use in T 1-weighted MR and/or infrared thermal imaging-guided PTT of cancer.