NIR-Induced Disintegration of CuS-Loaded Nanogels for Improved Tumor Penetration and Enhanced Anticancer Therapy

Nanocarrier-based cancer therapy suffers from poor tumor penetration and unsatisfied therapeutical efficacy, as its vascular extravasation efficiency is often compromised by the intrinsic physiological heterogeneity in tumor tissues. In this work, novel near infrared (NIR)-responsive CuS-loaded nanogels are prepared to deliver anticarcinogen into the tumor. These hybrid polymeric nanogels possess high photothermal conversion efficiency, and are able to load a large amount of antitumor drug (e.g., doxorubicin [DOX]). More importantly, the thermal heat could induce self-destruction of the big-size framework of hybrid nanogels into small nanoparticles, which greatly facilitates tumor penetration to release DOX deep inside the tumor, as validated by photoacoustic (PA) imaging which exhibits 26.3 times enhancement at the interior region compared to signals of groups without laser irradiation. Such structural alteration, combined with strong photothermal and chemotherapy effects, leads to remarkable inhibition of tumor growth in mice. As a result, this NIR-induced disintegration of CuS-loaded nanogels provides a novel drug delivery strategy and might open a new window for clinical cancer treatment.