Peptide-Functionalized Phase-Transformation Nanoparticles for Low Intensity Focused Ultrasound-Assisted Tumor Imaging and Therapy.

In this study, we successfully developed novel tumor homing-penetrating peptide-functionalized drug-loaded phase-transformation nanoparticles (tLyP-1-10-HCPT-PFP NPs) for low intensity focused ultrasound (LIFU)-assisted tumor ultrasound molecular imaging and precise therapy. With the nanoscale particle size, tLyP-1-10-HCPT-PFP NPs could pass through the tumor vascular endothelial cell gap. Induced by tLyP-1 peptide with targeting and penetrating efficiency, tLyP-1-10-HCPT-PFP NPs could increase tumor accumulation and penetrate deeply into the extravascular tumor tissue, penetrating through extracellular matrix and the cellular membrane to the cytoplasm. With LIFU assistance, tLyP-1-10-HCPT-PFP NPs could phase-transform into microbubbles and enhance tumor ultrasound molecular imaging for tumor diagnosis. Furthermore, after further irradiation by LIFU, an intracellular "explosion effect" caused by acoustic droplet vaporization, ultrasound targeted microbubble destruction, and release of 10-HCPT could realize physicochemical synergistic antitumor therapy.