Targeted near-IR hybrid magnetic nanoparticles for in vivo cancer therapy and imaging

We report the use of immuno-targeted gold–iron oxide hybrid nanoparticles for laser-assisted therapy and for MRI-based imaging as demonstrated in xenograft colorectal cancer tumor model. Immuno-targeted gold–iron oxide nanoparticles selectively accumulate in SW1222 xenograft tumors as compared to the accumulation in non-antigen-expressing tumor xenografts. Effective photothermal treatment using near-IR laser irradiation (808 nm, 5 W cm− 2) application is shown where > 65% of the antigen-expressing tumor cells presented corrupt extracellular matrix and cytoplasmic acidophilia suggesting effectiveness of nanoparticle-assisted thermal therapy. Cell killing was confirmed by hematoxylin and eosin (H&E) histological staining where scar-like structure containing collagen bundles was observed in the treatment group. Further, systemically injected HNPs were shown to be effective T2 magnetic resonance (MR) imaging contrast agents, localized and detected at the antigen-expressing xenograft tumors. These findings suggest that the new class of bio-conjugated HNPs exhibits great potential for dual-therapy and diagnostics (theranostics) applications.From the Clinical EditorThis team reports the successful use of immuno-targeted gold-iron oxide hybrid nanoparticles for both laser-assisted therapy and MRI-based imaging in a xenograft colorectal cancer tumor model, demonstrating strong potentials for dual applications in cancer diagnosis and therapy.

Graphical AbstractGold hybrid nanoparticles (HNPs) targeted with A33 single-chain antibody showed efficacious photothermal therapy ablative capability after tumor trophic accumulation. Histological assessment of treated tumor showed over 65% necrosis on positive controls after a 14-day photothermal therapy with less < 5% necrosis resulting from non-specific ablation (negative control). Further magnetic-based imaging of fixed-tumor sample showed T2 contrast enhancement (> 50%) resulting from the accumulation of these HNPs. The use of HNPs for in vivo therapy and diagnosis (theranostics) applications is demonstrated.Figure optionsDownload high-quality image (311 K)Download as PowerPoint slide