Self-Assembled Metal-Organic Nanoparticles For Multimodal Imaging-Guided Photothermal Therapy Of Hepatocellular Carcinoma

Liver cancer is one of the most common malignant tumors in the world,especially hepatocellular carcinoma(HCC)which account for about 70～90%.According to cancer statistics,there are annually more than 780 thousand of patients diagnosed with liver cancer over the world,meanwhile 740 thousand patients died of liver cancer.The latest statistics show that the annual incidence of liver cancer in China is 466 thousand,of which 422 thousand patients are dead.Liver cancer has occupied the fourth of the cancer incidence and the third of cancer-associated mortality in China.Therefore,liver cancer has become one of the diseases that threaten our national health.At present,the treatment of liver cancer includes hepatectomy,liver transplantation,lobcal ablation,interventional therapy,radiotherapy,chemotherapy and targeted therapy.Although these therapies have improved the prognosis of some patients with liver cancer,the long-term survival rate is still low,and the cost of treatment is expensive.Therefore,early precise diagnosis,improvement of treatment effect,alleviating patient’s pain and reducing medical expenses have become difficult problems for the diagnosis and treatment of liver cancer.Photothermal therapy(PTT)is a novel minimally invasive treatment of tumors,irradiating the tumor site which is enriched of nanomaterials with photothermal property by using near infrared laser,employing its thermal property to generate local hyperthermia(over 42℃),and killing the tumor cells.Because of its advantages such as high efficiency,minimal invasion,less side effect and low cost,it has become a research hotspot in the field of tumor therapy.Multimodal imaging employs various imaging methods to present the lesion and overcomes the limitations of single imaging mode.Therefore,the combination of multimodal imaging and PTT could achieve accurate theranostics for tumor.In this study,we have synthesized a novel inorganic-organic self-assembled nanoparticle which combines the indocyanine green(ICG),a photosensitizer,and the manganese ion(Mn2+)under the protection of polyvinylpyrrolidone(PVP).The synthesized nanoparticles,possessing the virtues of strong near-infrared absorptivity,high photothermal conversion efficiency and multimodal imaging,are used for imaging and PTT of liver cancer.Experimental results show that the nanoparticle could significantly enrich at the tumor site via enhanced high permeability and retention(EPR)effect,and also could be monitored by fluorescence(FL),photoacoustic(PA)and magnetic resonance(MR)imaging,then guide the PTT of hepatocellular carcinoma.