The ultrahigh concentration of glutathione (GSH) inside tumors destroys reactive oxygen species (ROS)‐based therapy, improving the outcome of chemodynamic therapy (CDT)‐enhanced sonodynamic therapy (SDT) by depleting GSH is full of great challenge. Herein, PtCu3 nanocages are first reported as acting as a sonosensitizer with highly efficient ROS generation under ultrasound irradiation. In addition, PtCu3 nanocages can act as horseradish peroxidase‐like nanozymes, catalyzing the decomposition of H2O2 into •OH under acidic conditions for CDT. Surprisingly, PtCu3 nanocages can act as another kind of nanozyme, mimicking glutathione peroxidase (GSH‐Px), which plays an important role in accelerating GSH depletion by oxidizing molecules, further weakening the capacity of tumor cells scavenging ROS by GSH. Both in vitro and in vivo studies demonstrate that PtCu3 nanocages perform well in reducing GSH level for CDT‐enhanced SDT. Moreover, utilizing the high absorption in the near‐infrared region and strong X‐ray attenuation ability, the PtCu3 nanocages are able to conduct photoacoustic/computed tomography dual‐modal imaging‐guided combined cancer therapy. It is worth mentioning that PtCu3 nanocages cause minimal toxicity to normal tissues at therapeutic doses. This work highlights the use of PtCu3 nanocages for effective CDT‐enhanced SDT via GSH depletion.

Materials that exhibit X-ray excited luminescence have great potential in radiation detection, security inspection, biomedical applications, and X-ray astronomy [1][2][3][4] . However, such materials are almost exclusively limited to inorganic crystals, which are typically prepared under high temperatures 5 . Herein, we report a design principle of purely organic phosphors to boost X-ray excited luminescence with sufficient utilization of triplet excitons. Our experimental data reveal that proportion of emission from bright triplet excitons is significantly improved upon X-ray irradiation, compared with UV excitation. These organic phosphors have a detection limit of 33 nGy/s, which is 167 times lower than the standard dosage for X-ray medical examinations. We further demonstrated their potential application in X-ray radiography, which can be conveniently recorded using a digital camera. These findings illustrate a fundamental principle to design efficient X-ray excited purely organic phosphors, propelling the development of radioluminescence related applications.X-ray-responsive materials generally display large X-ray attenuation coefficients because of high atomic number elements, which have aroused intense research interest owing to their wide applications in bioimaging, radiotherapy, and non-destructive defect detection of industrial products [6][7][8][9][10] . Such X-ray-responsive materials include non-emissive radiocontrast agents (e.g., iohexol and iopromide) and scintillators that can convert high energy X-ray beam into low-energy visible photons 2,11,12 . To date, almost all reported X-ray-sensitive materials are limited to inorganic phosphors or organometallic materials containing heavy metals 13 . Purely organic materials, also termed as metal-free organic phosphors, have congenital advantages as scintillator candidates, including abundant resources, flexibility, mild preparation conditions, and environmental friendliness. However, weak X-ray absorption and low exciton utilization hinder the development of purely organic scintillators 12 , leaving it a formidable challenge. Purely organic phosphors are mainly made up of light atoms, such as C, H, N, etc., resulting in weak absorbance of X-ray (attenuation coefficient μ ∝Z , Equation S1). Besides, there only exists fluorescence from singlet excitons upon irradiation owing to weak spin-orbit coupling (SOC). In principle, almost all triplet excitons,

AgS nanoparticles are increasingly important in biomedicine, such as in cancer imaging. However, there has been only limited success in the exploration of theranostic AgS nanoparticles for photoinduced cancer imaging and simultaneous therapy. Here we report size-dependent AgS nanodots (NDs) with well-defined nanostructure as a theranostic agent for multimodal imaging and simultaneous photothermal therapy. The NDs are precisely synthesized through carefully controlled growth of AgS in hollow human serum albumin nanocages. These NDs produce effective fluorescence in second near-infrared (NIR-II) region, distinct photoacoustic intensity, and good photothermal conversion in a size-dependent manner under light irradiation, thereby generating sufficient in vivo fluorescence and photoacoustic signals as well as potent hyperthermia at tumors. Moreover, AgS NDs possess ideal resistance to photobleaching, effective cellular uptake, preferable tumor accumulation, and in vivo elimination, thus facilitating NIR-II fluorescence/photoacoustics imaging with both ultrasensitivity and microscopic spatial resolution and simultaneous photothermal tumor ablation. These findings provide insight into the clinical potential of AgS nanodots for cancer theranostics.

Photodynamic therapy (PDT), as an emerging clinically approved modality, has been used for treatment of various cancer diseases. Conventional PDT strategies are mainly focused on superficial lesions because the wavelength of illumination light of most clinically approved photosensitizers (PSs) is located in the UV/VIS range that possesses limited tissue penetration ability, leading to ineffective therapeutic response for deep-seated tumors. The combination of PDT and nanotechnology is becoming a promising approach to fight against deep tumors. Here, the rapid development of new PDT modalities based on various smartly designed nanocomposites integrating with conventionally used PSs for deep tumor treatments is introduced. Until now many types of multifunctional nanoparticles have been studied, and according to the source of excitation energy they can be classified into three major groups: near infrared (NIR) light excited nanomaterials, X-ray excited scintillating/afterglow nanoparticles, and internal light emission excited nanocarriers. The in vitro and in vivo applications of these newly developed PDT modalities are further summarized here, which highlights their potential use as promising nano-agents for deep tumor therapy.

Synergistic phototherapy has the potential to conquer the extreme heterogeneity and complexity of difficult tumors and result in better cancer treatment outcomes than monomodal photodynamic therapy (PDT) or photothermal therapy (PTT). However, the previous approaches to combining PDT and PTT are mainly focused on primary tumor obliteration while neglecting tumor metastasis, which is responsible for about 90% of cancer deaths. It is shown that a combined PDT/PTT approach, based on upconversion‐polymer hybrid nanoparticles with surface‐loaded chlorin e6 photosensitizer, can enhance primary tumor elimination and elicit antitumor immunity against disseminated tumors. The specifical arrangement of an external upconversion coating over the polymer core ensures adequate photoabsorption by the upconversion nanoparticles for the generation of reactive oxygen species upon single near‐infrared light irradiation. Furthermore, it is found that synergistic phototherapy can elicit robust systemic and humoral antitumor immune responses. When combined with immune checkpoint blockades, it can inhibit tumor relapse and metastasis as well as prolong the survival of tumor‐bearing mice in two types of tumor metastasis models. This study may establish a new modality for enhancing immunogenic cell death through a synergistic phototherapeutic nanoplatform and extend this strategy to overcome tumor metastasis with an augmented antitumor immune response.