Magnetic graphene-based nanotheranostic agent for dual-modality mapping guided photothermal therapy in regional lymph nodal metastasis of pancreatic cancer.

Although regional lymph nodes (RLN) dissection remains the only way to cure pancreatic cancer metastasis, it is unavoidably associated with sizable trauma, multiple complications, and low surgical resection rates. Thus, exploring a treatment approach for the ablation of drug-resistant pancreatic cancer is always of great concern. Moreover, reoperative and intraoperative mapping of RLN is also important during treatment, because only a few lymph nodes can be detected by the naked eye. In our study, graphene oxides modified with iron oxide nanoparticles (GO-IONP) as a nanotheranostic agent is firstly developed to diagnose and treat RLN metastasis of pancreatic cancer. The approach was designed based on clinical practice, the GO-IONP agent directly injected into the tumor was transported to RLN via lymphatic vessels. Compared to commercial carbon nanoparticles currently used in the clinic operation, the GO-IONP showed powerful ability of dual-modality mapping of regional lymphatic system by magnetic resonance imaging (MRI), as well as dark color of the agent providing valuable information that was instrumental for surgeon in making the preoperative plan before operation and intraoperatively distinguish RLN from surrounding tissue. Under the guidance of dual-modality mapping, we further demonstrated that metastatic lymph nodes including abdominal nodes could be effectively ablated by near-infrared (NIR) irradiation with an incision operation. The lower systematic toxicity of GO-IONP and satisfying safety of photothermal therapy (PTT) to neighbor tissues have also been clearly illustrated in our animal experiments. Using GO-IONP as a nanotheranostic agent presents an approach for mapping and photothermal ablation of RLN, the later may serve as an alternative to lymph node dissection by invasive surgery.