Injectable Mechanophore Nanoparticles for Deep-Tissue Mechanochemical Dynamic Therapy

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Photodynamic therapy (PDT) and sonodynamic therapy (SDT) are promising cancer treatments but face limitations like poor tissue penetration (PDT) and potential tissue injury (SDT).
• Mechanochemical dynamic therapy (MDT) uses mechanophore-activated free radicals to generate reactive oxygen species (ROS), but in vivo applications are hindered by bulk materials and high ultrasound requirements.

Purpose of the Study:

• To develop injectable, nanoscale mechanophore particles with enhanced ultrasound sensitivity for cancer treatment.
• To overcome the limitations of existing MDT approaches for in vivo applications.

Main Methods:

• Engineered core-shell silica nanoparticles (NPs) functionalized with polymer brushes via azo mechanophore linkers.
• Utilized focused ultrasound (FUS) to activate the mechanophore moiety within the NPs.
• Evaluated ROS generation and therapeutic efficacy in vitro (4T1 cells) and in vivo (orthotopic breast cancer mouse model).

Main Results:

• The developed injectable NPs demonstrated enhanced ultrasound sensitivity.
• FUS treatment successfully triggered ROS generation from the nanoscale mechanophore particles.
• Promising anti-cancer effects were observed in both in vitro and in vivo models.

Conclusions:

• Injectable nanoscale mechanophore particles offer a viable platform for ultrasound-activated cancer therapy.
• This approach integrates force-responsive azo mechanophores and FUS under biocompatible conditions, presenting an alternative therapeutic strategy.
• The developed system shows potential for improved cancer treatment with localized ROS generation.