Gene Expression Modulation by Ultrasound-Responsive Biocatalytic 3D Scaffolds for Controlled Osteosarcoma Cell Elimination and Rat Cranial Bone Regeneration

Sonodynamic therapy (SDT) offers high efficiency and controllable precision in tumor eradication, while smart enzyme-mimetic materials enable pH-dependent switching between ROS generation and scavenging. Herein, we present HS-ICTO, a 3D-printed scaffold with ultrasound-triggered activation and microenvironment-responsive enzyme-mimetic properties, designed for spatiotemporally controlled therapeutic applications. The HS-ICTO scaffold synergistically enhances tumor elimination via TME-responsive ROS generation coupled with SDT effects, while switching to ROS scavenging in physiological conditions to protect stem cells. We conducted RNA sequencing on human osteosarcoma 143B cells treated with conventional scaffold (HS), HS-ICTO, and HS-ICTO + ultrasound (US), and performed comparative transcriptomic analysis of tissue cells in rat calvarial defect repair models implanted with HS versus HS-ICTO scaffolds. Overall design: To investigate the synergistic capacity of SDT and enzyme-mimetic ROS generation for tumor cell eradication, we seeded 143b cells on HS and HS-ICTO scaffolds and applied US irradiation for HS-ICTO + US group. After treatment, the RNA-seq was conducted. To investigate the ROS-scavenging capacity of HS-ICTO in safeguarding bone repair processes, we established rat calvarial defect models implanted with HS and HS-ICTO scaffolds. Four weeks post-implantation, the scaffolds were harvested, and RNA from intra-scaffold tissue cells was extracted for RNA-seq analysis