Ultrasound nanotheranostics: Toward precision medicine

Ultrasound (US) is a mechanical wave that can penetrate biological tissues and trigger complex bioeffects. The mechanisms of US in different diagnosis and treatment are different, and the functional application of com-mercial US is also expanding. In particular, recent developments in nanotechnology have led to a wider use of US in precision medicine. In this review, we focus on US in combination with versatile micro and nanoparticles (NPs)/nanovesicles for tumor theranostics. We first introduce US-assisted drug delivery as a stimulus-responsive approach that spatiotemporally regulates the deposit of nanomedicines in target tissues. Multiple functionalized NPs and their US-regulated drug-release curves are analyzed in detail. Moreover, as a typical representative of US therapy, sonodynamic antitumor strategy is attracting researchers' attention. The collaborative efficiency and mechanisms of US and various nano-sensitizers such as nano-porphyrins and organic/inorganic nanosized sen-sitizers are outlined in this paper. A series of physicochemical processes during ultrasonic cavitation and NPs activation are also discussed. Finally, the new applications of US and diagnostic NPs in tumor-monitoring and image-guided combined therapy are summarized. Diagnostic NPs contain substances with imaging properties that enhance US contrast and photoacoustic imaging. The development of such high-resolution, low-background US-based imaging methods has contributed to modern precision medicine. It is expected that the integration of non-invasive US and nanotechnology will lead to significant breakthroughs in future clinical applications.

Automated summary

Ultrasound (US) is a mechanical wave that can penetrate biological tissues and has diverse applications in diagnosis and treatment. With the advancements in nanotechnology, US has found wider applications in precision medicine, particularly in tumor theranostics. This review focuses on the combination of US with micro and nanoparticles for tumor theranostics, discussing topics such as US-assisted drug delivery and sonodynamic antitumor strategy. The collaborative efficiency and physicochemical processes of US and nano-sensitizers are also analyzed. Furthermore, the review highlights the new applications of US and diagnostic nanoparticles in tumor monitoring and image-guided combined therapy.