Noninvasive imaging of tumor hypoxia after nanoparticle-mediated tumor vascular disruption

Area of Science:

• Biomedical Engineering
• Oncology
• Nanotechnology

Background:

• Endothelial targeting of gold nanoparticles with external beam irradiation disrupts tumor vasculature.
• Tumor vascular disruption can induce physiological changes like hypoxia, potentially hindering therapy.
• Understanding these dynamic changes is crucial for optimizing cancer treatment strategies.

Purpose of the Study:

• To investigate the dynamic changes in tumor hypoxia following vascular-targeted gold nanoparticles and radiation therapy (RT).
• To assess the physiological response and recovery of tumor hypoxia after combined therapy.
• To evaluate the impact of this combined approach on tumor growth suppression.

Main Methods:

• Utilized a human non-small cell lung cancer athymic Foxn1nu mouse model.
• Administered vascular-targeted gold nanoparticles followed by clinical radiation therapy.
• Employed noninvasive whole-body fluorescence imaging to measure tumor hypoxia at baseline, day 2, and day 13 post-treatment.

Main Results:

• A 2.5-fold increase in tumor hypoxia was observed two days after the combined therapy (P<0.05).
• Tumor hypoxia levels returned towards baseline by day 13, indicating a recovery phase.
• The combination therapy significantly suppressed tumor growth (P<0.05).

Conclusions:

• This study is the first to demonstrate the dynamic hypoxic physiological response and recovery after vascular-targeted gold nanoparticles and RT.
• Targeted gold nanoparticles combined with RT effectively disrupt tumor vasculature and suppress tumor growth.
• The findings provide insights into the temporal effects of this combined modality on tumor microenvironment and growth.