Ultrasound-triggered lysosomal alkalinization to block autophagy in tumor therapy

Lysosomes play a crucial role in regulating cancer progression and drug resistance. However, there is a pressing need for the development of drugs that can safely and effectively modulate the pH of cancerous lysosomes in a controlled manner. In this study, we propose a novel strategy for lysosomal alkalinization triggered by piezoelectricity. Our findings indicate that the electrons generated by (BaTiO₃/Zr/Ca) BCZT under sonication effectively alkalinize the lysosomes. Molecular dynamics simulations further demonstrate that alterations in lysosomal pH lead to modifications in the conformation of V-ATPase (proton pump), enhancing its interaction with sodium ions while partially excluding hydrogen ions from entering the lysosomes. This mechanism helps maintain lysosomal alkalization, resulting in reduced hydrolase activity and preventing the degradation of proteins and damaged organelles. The accumulation of nanoparticles within the lysosomes causes swelling and gradual destruction of the lysosomal membrane. Consequently, this lysosomal dysfunction hampers the fusion with autophagosomes, inhibiting autophagy in tumor cells and promoting apoptosis in various tumor types. Our strategy significantly inhibited tumor volume growth in mice during animal studies. In conclusion, our piezoelectric-triggered lysosomal alkalinization strategy holds promise for innovative breakthroughs in the treatment of multiple cancers.