FA-NBs-IR780: Novel multifunctional nanobubbles as molecule-targeted ultrasound contrast agents for accurate diagnosis and photothermal therapy of cancer.

Early accurate diagnosis and targeted therapy for cancer are essential to improve the prognosis of patients. With the emergence of molecular imaging, molecule-targeted ultrasound imaging for the non-invasive and precise detection of cancer has attracted increased attention. The investigation of molecule-targeted ultrasound contrast agents (UCAs) with excellent performance is urgently needed. In this study, we synthetized folic acid and IR-780 on self-made nanobubbles and prepared novel UCAs, named FA-NBs-IR780. The results showed that the conjugates had a uniform size distribution (591 ± 52 nm). In vitro and in vivo experiments demonstrated that FA-NBs-IR780 can target tumour cells via dual molecular targeting, perform enhanced-contrast ultrasound imaging and near-infrared fluorescence (NIRF) imaging for the precise detection of tumours, and induce targeted photothermal therapy in lesions irradiated at 808 nm. Ex vivo experiments further confirmed that FA-NBs-IR780 efficiently induced tumour cell apoptosis and inhibited tumour growth. The newly fabricated FA-NBs-IR780 were observed to be molecule-targeted dual-mode UCAs and may have potential applications in early accurate diagnosis and targeted therapy of cancer in the future.