NIR-light emitting CDs (R-CDs) were prepared using spinach as a precursor by one-step solvothermal treatment. The R-CDs exhibited great optical properties, negligible toxicity, and superior labelling capability both in vitro and in vivo.

A photoacoustic imaging-guided anticancer strategy was developed based on poly-l-lysine functionalized melanin nanoparticles by integrating thermo-gene therapies.

Multi-modal imaging-guided photothermal therapy (PTT) has aroused extensive attention in biomedical research recently because it can provide more comprehensive information for accurate diagnosis and treatment. In this research, the manganese ion chelated endogenous biopolymer melanin nanoparticles were successfully prepared for magnetic resonance (MR)/photoacoustic (PA) dual-modal imaging-guided PTT. The obtained nanoparticles with an ultrasmall size of about 3.2 nm exhibited negligible cytotoxicity, high relaxivity for MRI, an excellent photothermal effect and PA activity. Moreover, in vivo MRI and PAI results all demonstrated that the nanoparticles began to diffuse in the blood after intratumoral injection into tumor-bearing mice and could spread throughout the whole tumor region at 3 h, indicating the optimal treatment time. The subsequent photothermal therapy of cancer cells in vivo was carried out and the result showed that tumor growth could be effectively inhibited without inducing any observed side effects. Besides, melanin as an endogenous biopolymer has native biocompatibility and biodegradability, and it can be excreted through both renal and hepatobiliary pathways after treatment. Therefore, the melanin-Mn nanoparticles may assist in better indicating the optimal treatment time, monitoring the therapeutic process and enhancing the therapeutic effect and showed great clinical translation potential for cancer diagnosis and therapy.

Regulating the level of reactive oxygen species (ROS) in a tumor is an efficient and innovative anticancer strategy. However, the therapeutic efficacy of ROSbased therapies, such as chemodynamic therapy (CDT) and photodynamic therapy (PDT), offers finite outcomes due to the oxygen dependence and limited concentration of hydrogen peroxide (H 2 O 2 ) and overexpression of glutathione (GSH) within the tumor microenvironment (TME), so a single therapeutic strategy is insufficient to completely eliminate tumors. Therefore, we demonstrated an omnipotent nanoplatform MnO 2 / Ag 3 SbS 3 (abbreviated as MA) with strong optical absorbance in the NIR-II biowindow and oxygen self-sufficient ROS-mediated ability, which not only relieves tumor hypoxia significantly but also enhances the photothermal therapy (PTT)/PDT/CDT efficacy. By 1064 nm laser irradiation, MnO 2 /Ag 3 SbS 3 nanoparticles (NPs) reveal a favorable photothermal conversion efficiency of 23.15% and achieve a single-laser-triggered NIR-II PTT/PDT effect, resulting in effective tumor elimination. Once internalized into the tumor, MnO 2 /Ag 3 SbS 3 NPs will be degraded to Mn 2+ and Ag 3 SbS 3 . The released Ag 3 SbS 3 NPs as a NIR-II phototherapy agent could be utilized for photoacoustic imaging-guided NIR-II PDT/PTT. Mn 2+ could be used as a Fenton-like catalyst to continuously catalyze endogenous H 2 O 2 for generating highly virulent hydroxyl radicals ( • OH) for CDT and O 2 for PDT, enhancing the efficiency of PDT and CDT, respectively. Meanwhile, Mn 2+ realizes magnetic resonance imaging-guided accurate tumor therapy. Moreover, the MnO 2 /Ag 3 SbS 3 NPs could deplete intracellular GSH in TME to promote oxidative stress of the tumor, further strengthening ROS-mediated antitumor treatment efficacy. Overall, this work presents a distinctive paradigm of TME-responsive PDT/CDT/PTT in the second near-infrared biowindow by depleting GSH and decomposing H 2 O 2 for efficient and precise cancer treatment.