Synergistic enhancement of ultrasound therapy for tumors using hypoxia-activated 6-diazo-5-oxo-L-norleucine(DON)prodrug nanoparticles

Ultrasound(US)has been applied in clinical practice for its non-invasive and high selectivity.However,it is difficult to achieve a satisfactory anti-tumor effect with US alone.Meanwhile,the use of US therapy alone can exacerbate tumor hypoxia.In this study,we prepared hypoxia-activated 6-diazo-5-oxo-L-norleucine(DON)prodrug nanoparticles(HDON-NPs)to improve US therapeutic effects.In an H22 murine liver cancer model,US therapy selectively disrupted tumor blood vessels,leading to increased tumor hypoxia and a 1.67-fold increase in the expression of nitroreductase(NTR).The combination therapy of US and HDON-NPs demonstrated a synergistic effect,resulting in a tumor suppression rate(TSR)of 90.2%±6.4%,which was 5.93-fold higher than that of US therapy alone.The combined treatment selectively blocked the glutamine metabolism of the tumor cells while simultaneously activating the T cells in the tumor microenvironment,thereby exerting a robust anti-tumor effect.

Multifunctional magnetic nanoparticles for magnetic resonance image-guided photothermal therapy for cancer

Key advances in multifunctional magnetic nanoparticles （MNPs） for magnetic resonance （MR） image-guided pho- tothermal therapy of cancer are reviewed. We briefly outline the design and fabrication of such multifunctional MNPs. Bimodal image-guided photothermal therapies （MR/fluorescence and MR/ultrasound） are also discussed.