Clothing spiny nanoprobes against the mononuclear phagocyte system clearance in vivo: Photoacoustic diagnosis and photothermal treatment of early stage liver cancer with erythrocyte membrane-camouflaged gold nanostars

Nanoprobes have been increasingly applied in photoacoustic imaging to improve the diagnosis and treatment of diseases, especially the liver cancer, the fourth leading cause of cancer-related deaths worldwide. The mononuclear phagocytic system (MPS), however, exhibits a crucial impediment to the probe usage, preventing the accumulation of probes within the liver. This, in turn, paralyzes the effort of diagnosis enhancement. To overcome the MPS clearance, a biomimetic probe consisting of erythrocyte membrane-camouflaged gold nanostars was designed and synthesized in this study. The probe possesses broad absorption spectrum, photostability, and photothermal conversion efficiency. More importantly, it yields preeminent immune escape ability, thus being able to escape the MPS clearance and greatly boost the accumulation of probes at the tumor sites with prolonged blood circulation. Experimentally, we demonstrate that the probe can serve as an effective nanoprobe to enhance the in vivo photoacoustic imaging and photothermal treatment of in situ early stage liver tumors in mice.