Targeting and destroying tumor vasculature with a near-infrared laser-activated "nanobomb" for efficient tumor ablation

Attacking the supportive vasculature network of a tumor offers an important new avenue for cancer therapy. Herein, a near-infrared (NIR) laser-activated "nanobomb" was developed as a noninvasive and targeted physical therapeutic strategy to effectively disrupt tumor neovasculature in an accurate and expeditious manner. This "nanobomb" was rationally fabricated via the encapsulation of vinyl azide (VA) into c(RGDfE) peptide-functionalized, hollow copper sulfide (HCuS) nanoparticles. The resulting RGD@HCuS(VA) was selectively internalized into integrin alpha(v)beta(3)-expressing tumor vasculature endothelial cells and dramatically increased the photoacoustic signals from the tumor neovasculature, achieving a maximum signal-to-noise ratio at 4 h post-injection. Upon NIR irradiation, the local temperature increase triggered VA to release N-2 bubbles rapidly. Subsequently, these N-2 bubbles could instantly explode to destroy the neovasculature and further induce necrosis of the surrounding tumor cells. A single-dose injection of RGD@HCuS(VA) led to complete tumor regression after laser irradiation, with no tumor regrowth for 30 days. More importantly, high-resolution photoacoustic angiography, combined with excellent biodegradability, facilitated the precise destruction of tumor neovasculature by RGD@HCuS(VA) without damaging normal tissues. These results demonstrate the great potential of this "nanobomb" for clinical translation to treat cancer patients with NIR laser-accessible orthotopic tumors. (C) 2017 Elsevier Ltd. All rights reserved.