Surface-engineered carbon nanohorns as a theranostic nanodevice for photoacoustic imaging and effective radiochemotherapy of cancer

Abstract Multifunctional nanodevices have shown great promise as robust tools in cancer theranostics. Carbon nanohorns (CNHs) of large specific surface area, low toxicity and unique physicochemical properties are among one of ideal platforms to fabricate the nanodevices. Herein, we develop a water-dispersible carbon nanohorn−polyglycerol−gold (CNH-PG-Au) nanohybrid through surface engineering of CNHs, which is further loaded with chemotherapeutic drug doxorubicin (DOX) to afford DOX@CNH-PG-Au nanodevice. Benefiting from the excellent hydrophilicity of PG, as-prepared multifunctional DOX@CNH-PG-Au possesses good aqueous dispersibility and colloidal stability enabling biomedical applications. DOX@CNH-PG-Au nanoparticles are taken up by 4T1 mouse breast cancer cells and mainly disperse in the lysosomes, where the mild acidic condition promotes the release of DOX. DOX@CNH-PG-Au induces more cell apoptosis under X-ray irradiation than DOX@CNH-PG of the same DOX concentrations, which is attributed to increased DNA damage by synergistic effect of DNA intercalation of DOX and radiosensitization of Au nanoparticles. Upon intravenous administration, DOX@CNH-PG-Au nanoparticles steadily accumulate in 4T1 tumor through enhanced permeability and retention (EPR) effect, and the tumor can be clearly observed by photoacoustic imaging. In vivo tumor treatment using DOX@CNH-PG-Au together with X-ray irradiation effectively inhibits tumor growth through radiochemotherapy. Our work demonstrates the great potential of DOX@CNH-PG-Au nanodevice in cancer theranostics.