Injectable and NIR-Responsive DNA-Inorganic Hybrid Hydrogels with Outstanding Photothermal Therapy.

Surgical excision is one of the main treatments for malignant tumors. However, high risk of tumour recurrence is a major challenge. Near-infrared (NIR)-light-induced tumor photothermal therapy has been studied, while its clinical applications are still restricted due to the limited therapeutic effects. To address this, here, a novel NIR-light-responsive and injectable DNA-mediated upconversion and Au nanoparticle hybrid (DNA-UCNP-Au) hydrogel is developed. Due to the confined and concentrated environment induced by the interaction between adjacent DNA strands and UCNP-Au NPs, an ultrastrong photothermal effect is observed. A photothermal efficiency as high as 42.7% is realized in the hydrogel, which is superior to pristine inorganic particles. Upon direct peritumoral injection of the hydrogel and with the treatment of 808 nm laser irradiation, tumors are eradicated and no recurrence is observed. Meanwhile, there are no side effects on normal tissues due to the local treatment. Taking advantage of the high phototherapeutic effect, biocompatibility, and flexible operability in this system, a novel approach for malignant tumor therapy is demonstrated.