Piezoelectric Nanoparticles for Ultrasound-Based Wireless Therapies

Piezoelectric materials can convert ultrasound-based mechanical energy into electrical energy and associated electrochemical reactions, and they have attracted a wide range of applications in energy harvesting, wastewater treatment, and catalysis. In biomedical science, these piezoelectric materials have been used in ultrasound-based therapy and sonodynamic therapy. In particular, the noninvasive nature and high tissue-penetrating ability of ultrasound offer various wireless therapies at remote areas that include generation of reactive oxygen species at the intra/extracellular space, electrical stimulation of cell/brain/tissue, tumor ablation, and antibacterial activity. The most challenging aspects of these biomedical applications include the design of the nanoparticle form of piezoelectric materials, optimization of the piezocatalytic condition, and understanding of triggered bioeffects. This Spotlight on Applications will focus on recent advances on piezoelectric nanomaterial-based wireless therapy. At first we discuss the piezoelectric materials and nanoparticles, the principle of ultrasound-based piezoelectric response, and piezocatalytic reactions at their surface. Next, we discuss the approaches in constructing different piezoelectric nanoplatforms for wireless therapies. Finally, we summarize the reported wireless therapeutic approaches toward neuronal cell stimulation, combating neurodegenerative disease, antibacterial effect and fouling treatment, cancer cell and tumor therapy, regenerative medicine and tissue engineering, and health monitoring. Current challenges and future directions are discussed for further expansion of the field.