Facile synthesis of a metal–organic framework nanocarrier for NIR imaging-guided photothermal therapy

The NIR dye cyanine (Cy) is one of the most significant phototherapy agents (PTAs) due to its strong NIR absorbance, high thermal conversion capacity and good safety. However, its clinic application is seriously limited owing to its inherent properties as an organic dye, including low solubility, poor selectivity, and fast clearance. Thus, herein, we embed Cy into the zeolitic imidazolate framework-8 (Cy@ZIF-8) for antitumor photothermal therapy (PTT). The obtained Cy@ZIF-8 NPs not only have good water solubility and excellent photostability, but also exhibit strong NIR absorbance and great photothermal conversion efficiency. Especially, the Cy@ZIF-8 NPs efficaciously inhibit tumor growth and possess outstanding NIR imaging capacity both in vitro and in vivo. This work demonstrates the theranostic value of Cy@ZIF-8 NPs for imaging-guided PTT therapy, and also encourages the further study of other PTAs@ZIF-8 composites for better anticancer PTT.