Tumor Microenvironment-Responsive Zn(II)-Porphyrin Nanotheranostics for Targeted Sonodynamic Therapy.

As a novel noninvasive tumor therapy, sonodynamic therapy (SDT) attracts booming concerns. However, the limited water solubility, inadequate biocompatibility, and low targeting ability of conventional sonosensitizers significantly hinder their potential for clinical application. Herein, novel zinc(II)-porphyrin nanotheranostics (HA@Zn-TCPP) were fabricated in which the zinc(II)-porphyrin (TCPP) metal-organic framework was first constructed by a simple thermal reaction, followed by the addition of hyaluronic acid (HA) for modification. The specific targeting ability of HA facilitated the internalization of HA@Zn-TCPP within tumor cells, resulting in its preferential accumulation in tumor tissues that exhibit CD44 receptor overexpression. The acidic tumor microenvironment induced the rapid decomposition of HA@Zn-TCPP, releasing free TCPP for activating SDT. This controllable generation of reactive oxygen species (ROS) could effectively decrease damage to normal tissues. The HA@Zn-TCPP exhibited remarkable antitumor effects in experiments, achieving a tumor inhibition rate of up to 82.1% when under ultrasound. This finding provides an imperative strategy to develop novel sonosensitizers for enhanced SDT.