Emerging Strategies of Nanomaterial-Mediated Tumor Radiosensitization

Current status of nanoparticle-mediated immunogenic cell death in cancer immunotherapy

Immunogenic cell death (ICD) encompasses various forms of cell death modalities, including apoptosis, necroptosis, ferroptosis, and pyroptosis. It arises from a harmonious interplay of adjuvant (damage-associated molecular patterns-DAMPs and chemokines/cytokines) and antigenicity (tumor-associated antigens-TAA) to induce immune-reaction toward cancer cells. Inducing ICD stands out as a promising approach in cancer immunotherapy, capable of directly eliminating cancer cells and of eliciting enduring antitumor immune responses. Conventional tumor therapies like radiation therapy, photodynamic therapy, and chemotherapy can also induce ICD which could amplify their activities. The development of effective ICD inducers like nano-systems is crucial for ensuring safe and efficacious immunotherapy. Nanoparticles hold considerable promise in cancer therapy, offering enhanced therapeutic outcomes and mitigated side effects. They could be the capacity to adjust systemic biodistribution, augment the accumulation of therapeutic agents at the intended site and protect active agents from the complexity of human biofluid. This review aims to outline the role of nanoparticles in triggering ICD for cancer immunotherapy that potentially pave the way for cancer treatment.

Application progress of nanomaterials in the treatment of prostate cancer

Prostate cancer is one of the most common malignant tumors in men, which seriously threatens the survival and quality of life of patients. At present, there are serious limitations in the treatment of prostate cancer, such as drug tolerance, drug resistance and easy recurrence. Sonodynamic therapy and chemodynamic therapy are two emerging tumor treatment methods, which activate specific drugs or sonosensitizers through sound waves or chemicals to produce reactive oxygen species and kill tumor cells. Nanomaterials are a kind of nanoscale materials with many excellent physical properties such as high targeting, drug release regulation and therapeutic monitoring. Sonodynamic therapy and chemodynamic therapy combined with the application of nanomaterials can improve the therapeutic effect of prostate cancer, reduce side effects and enhance tumor immune response. This article reviews the application progress of nanomaterials in the treatment of prostate cancer, especially the mechanism, advantages and challenges of nanomaterials in sonodynamic therapy and chemodynamic therapy, which provides new ideas and prospects for research in this field.

Lipiodol emulsion as a dual chemoradiation-sensitizer for pancreatic cancer treatment

Pancreatic ductal adenocarcinoma (PDAC) has a low survival rate and limited treatment options. Concurrent chemoradiotherapy is considered beneficial to improve tumor control, but the low drug bioavailability at tumor site and the low radiation tolerance of surrounding healthy organs greatly limits its effectiveness. Lipiodol, a natural drug carrier used in clinical transarterial chemoembolization, has shown potential as a radiosensitizer due to its high Z element iodine composition. Thus, this study aims to repurpose lipiodol as a sensitizer to simultaneously enhance chemo- and radiotherapy for PDAC. To this end, a stable lipiodol emulsion (IOE) loaded with gemcitabine is designed using clinically approved surfactants. At in vivo level, IOE demonstrates better radiotherapeutic effect than existing nanoradiosensitizers and enhanced drug bioavailability over free drug, leading to significant tumor inhibition and improved survival rates under concurrent chemo-radiotherapy. This may due to the sustained drug release, homogenous spatial distribution, and long-term retention ability of IOE in solid PDAC tumor. Furthermore, to better understand the functioning mechanism of drug-loaded IOE, in vitro study is conducted to reveal the ROS- and DNA damage-related therapeutic pathways. Lastly, a comprehensive toxicity assessment also proves the good biocompatibility and safety of as-prepared IOE. This study offers a clinically feasible sensitizer for simultaneous chemoradiotherapy and holds potential for other types of cancer treatment in clinics.

Computed Tomography Imaging Guided Microenvironment-Responsive Ir@WO3-x Dual-Catalytic Nanoreactor for Selective Radiosensitization

Radiotherapy (RT) is often administered, either alone or in combination with other therapies, for most malignancies. However, the degree of tumor oxygenation, damage to adjacent healthy tissues, and inaccurate guidance remain issues that result in discontinuation or failure of RT. Here, a multifunctional therapeutic platform based on Ir@WO3-x is developed which simultaneously addresses these critical issues above for precision radiosensitization. Ir@WO3-x nanoreactors exhibit strong absorption of X-ray, acting as radiosensitizers. Moreover, ultrasmall Ir enzyme-mimic nanocrystals (NCs) are decorated onto the surface of the nanoreactor, where NCs have catalyst-like activity and are sensitive to H2O2 in the tumor microenvironment (TME) under near infrared-II (NIR-II) light stimulation. They efficiently catalyze the conversion of H2O2 to O2, thereby ameliorating hypoxia, inhibiting the expression of HIF-1α, and enhancing RT-induced DNA damage in cancerous tissue, further improving the efficiency of RT. Additionally, in response to high H2O2 levels in TME, the Ir@WO3-x nanoreactor also exerts peroxidase-like activity, boosting exogenous ROS, which increases oxidative damage and enhances ROS-dependent death signaling. Furthermore, Ir@WO3-x can serve as a high-quality computed tomography contrast agent due to its high X-ray attenuation coefficient and generation of pronounced tumor-tissue contrast. This report highlights the potential of advanced health materials to enhance precision therapeutic modalities.

Selenium-Doped Nanoheterojunctions for Highly Efficient Cancer Radiosensitization

Exploring efficient and low-toxicity radiosensitizers to break through the bottleneck of radiation tolerance, immunosuppression and poor prognosis remains one of the critical developmental challenges in radiotherapy. Nanoheterojunctions, due to their unique physicochemical properties, have demonstrated excellent radiosensitization effects in radiation energy deposition and in lifting tumor radiotherapy inhibition. Herein, they doped selenium (Se) into prussian blue (PB) to construct a nano-heterojunction (Se@PB), which could promote the increase of Fe2+/Fe3+ ratio and conversion of Se to a high valence state with Se introduction. The Fe2+-Se-Fe3+ electron transfer chain accelerates the rate of electron transfer on the surface of the nanoparticles, which in turn endows it with efficient X-ray energy transfer and electron transport capability, and enhances radiotherapy physical sensitivity. Furthermore, Se@PB induces glutathione (GSH) depletion and Fe2+ accumulation through pro-Fenton reaction, thereby disturbs the redox balance in tumor cells and enhances biochemical sensitivity of radiotherapy. As an excellent radiosensitizer, Se@PB effectively enhances X-ray induced mitochondrial dysfunction and DNA damage, thereby promotes cell apoptosis and synergistic cervical cancer radiotherapy. This study elucidates the radiosensitization mechanism of Se-doped nanoheterojunction from the perspective of the electron transfer chain and biochemistry reaction, which provides an efficient and low-toxic strategy in radiotherapy.

Magnetic-guided nanocarriers for ionizing/non-ionizing radiation synergistic treatment against triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with the worst prognosis. Radiotherapy (RT) is one of the core modalities for the disease; however, the ionizing radiation of RT has severe side effects. The consistent development direction of RT is to achieve better therapeutic effect with lower radiation dose. Studies have demonstrated that synergistic effects can be achieved by combining RT with non-ionizing radiation therapies such as light and magnetic therapy, thereby achieving the goal of dose reduction and efficacy enhancement.

METHODS

In this study, we applied FeCo NPs with magneto thermal function and phototherapeutic agent IR-780 to construct an ionizing and non-ionizing radiation synergistic nanoparticle (INS NPs). INS NPs are first subjected to morphology, size, colloidal stability, loading capacity, and photothermal conversion tests. Subsequently, the cell inhibitory and cellular internalization were evaluated using cell lines in vitro. Following comprehensive assessment of the NPs' in vivo biocompatibility, tumor-bearing mouse model was established to evaluate their distribution, targeted delivery, and anti-tumor effects in vivo.

RESULTS

INS NPs have a saturation magnetization exceeding 72 emu/g, a hydrodynamic particle size of approximately 40 nm, a negatively charged surface, and good colloidal stability and encapsulation properties. INS NPs maintain the spectral characteristics of IR-780 at 808 nm. Under laser irradiation, the maximum temperature was 92 °C, INS NPs also achieved the effective heat temperature in vivo. Both in vivo and in vitro tests have proven that INS NPs have good biocompatibility. INS NPs remained effective for more than a week after one injection in vivo, and can also be guided and accumulated in tumors through permanent magnets. Later, the results exhibited that under low-dose RT and laser irradiation, the combined intervention group showed significant synergetic effects, and the ROS production rate was much higher than that of the RT and phototherapy-treated groups. In the mice model, 60% of the tumors were completely eradicated.

CONCLUSIONS

INS NPs effectively overcome many shortcomings of RT for TNBC and provide experimental basis for the development of novel clinical treatment methods for TNBC.

Ultrasound-Based Micro-/Nanosystems for Biomedical Applications

Due to the intrinsic non-invasive nature, cost-effectiveness, high safety, and real-time capabilities, besides diagnostic imaging, ultrasound as a typical mechanical wave has been extensively developed as a physical tool for versatile biomedical applications. Especially, the prosperity of nanotechnology and nanomedicine invigorates the landscape of ultrasound-based medicine. The unprecedented surge in research enthusiasm and dedicated efforts have led to a mass of multifunctional micro-/nanosystems being applied in ultrasound biomedicine, facilitating precise diagnosis, effective treatment, and personalized theranostics. The effective deployment of versatile ultrasound-based micro-/nanosystems in biomedical applications is rooted in a profound understanding of the relationship among composition, structure, property, bioactivity, application, and performance. In this comprehensive review, we elaborate on the general principles regarding the design, synthesis, functionalization, and optimization of ultrasound-based micro-/nanosystems for abundant biomedical applications. In particular, recent advancements in ultrasound-based micro-/nanosystems for diagnostic imaging are meticulously summarized. Furthermore, we systematically elucidate state-of-the-art studies concerning recent progress in ultrasound-based micro-/nanosystems for therapeutic applications targeting various pathological abnormalities including cancer, bacterial infection, brain diseases, cardiovascular diseases, and metabolic diseases. Finally, we conclude and provide an outlook on this research field with an in-depth discussion of the challenges faced and future developments for further extensive clinical translation and application.

A narrow-bandgap RuI3 nanoplatform to synergize radiotherapy, photothermal therapy, and thermoelectric dynamic therapy for tumor eradication

Therapeutic resistance is an essential challenge for nanotherapeutics. Herein, a narrow bandgap RuI3 nanoplatform has been constructed firstly to synergize radiotherapy (RT), photothermal therapy (PTT), and thermoelectric dynamic therapy (TEDT) for tumor eradication. Specifically, the photothermal performance of RuI3 can ablate tumor cells while inducing TEDT. Noteworthy, the thermoelectric effect is found firstly in RuI3, which can spontaneously generate an electric field under the temperature gradient, prompting carrier separation and triggering massive ROS generation, thus aggravating oxidative stress level and effectively inhibiting HSP-90 expression. Moreover, RuI3 greatly enhances X-ray deposition owing to its high X-ray attenuation capacity, resulting in a pronounced computed tomography imaging contrast and DNA damage. In addition, RuI3 possesses both catalase-like and glutathione peroxidase-like properties, which alleviate tumor hypoxia and reduce antioxidant resistance, further exacerbating 1O2 production during RT and TEDT. This integrated therapy platform combining PTT, TEDT, and RT significantly inhibits tumor growth. STATEMENT OF SIGNIFICANCE: RuI3 nanoparticles were synthesized for the first time. RuI3 exhibited the highest photothermal properties among iodides, and the photothermal conversion efficiency was 53.38 %. RuI3 was found to have a thermoelectric effect, and the power factor could be comparable to that of most conventional thermoelectric materials. RuI3 possessed both catalase-like and glutathione peroxidase-like properties, which contributed to enhancing the effect of radiotherapy.

A Dual-Channel Ca2+ Nanomodulator Induces Intracellular Ca2+ Disorders via Endogenous Ca2+ Redistribution for Tumor Radiosensitization

Tumor cells harness Ca2+ to maintain cellular homeostasis and withstand external stresses from various treatments. Here, a dual-channel Ca2+ nanomodulator (CAP-P-NO) is constructed that can induce irreversible intracellular Ca2+ disorders via the redistribution of tumor-inherent Ca2+ for disrupting cellular homeostasis and thus improving tumor radiosensitivity. Stimulated by tumor-overexpressed acid and glutathione, capsaicin and nitric oxide are successively escaped from CAP-P-NO to activate the transient receptor potential cation channel subfamily V member 1 and the ryanodine receptor for the influx of extracellular Ca2+ and the release of Ca2+ in the endoplasmic reticulum, respectively. The overwhelming level of Ca2+ in tumor cells not only impairs the function of organelles but also induces widespread changes in the gene transcriptome, including the downregulation of a set of radioresistance-associated genes. Combining CAP-P-NO treatment with radiotherapy achieves a significant suppression against both pancreatic and patient-derived hepatic tumors with negligible side effects. Together, the study provides a feasible approach for inducing tumor-specific intracellular Ca2+ overload via endogenous Ca2+ redistribution and demonstrates the great potential of Ca2+ disorder therapy in enhancing the sensitivity for tumor radiotherapy.

Breakthrough of Hypoxia Limitation by Tumor-Targeting Photothermal Therapy-Enhanced Radiation Therapy

Purpose

To address the problem of suboptimal reactive oxygen species (ROS) production in Radiation therapy (RT) which was resulted from exacerbated tumor hypoxia and the heterogeneous distribution of radiation sensitizers.

Materials and Methods

In this work, a novel nanomedicine, designated as PLGA@IR780-Bi-DTPA (PIBD), was engineered by loading the radiation sensitizer Bi-DTPA and the photothermal agent IR780 onto poly(lactic-co-glycolic acid) (PLGA). This design leverages the tumor-targeting ability of IR780 to ensure selective accumulation of the nanoparticles in tumor cells, particularly within the mitochondria. The effect of the photothermal therapy-enhanced radiation therapy was also examined to assess the alleviation of hypoxia and the enhancement of radiation sensitivity.

Results

The PIBD nanoparticles exhibited strong capacity in mitochondrial targeting and selective tumor accumulation. Upon activation by 808 nm laser irradiation, the nanoparticles effectively alleviated local hypoxia by photothermal effect enhanced blood supplying to improve oxygen content, thereby enhancing the ROS production for effective RT. Comparative studies revealed that PIBD-induced RT significantly outperformed conventional RT in treating hypoxic tumors.

Conclusion

This design of tumor-targeting photothermal therapy-enhanced radiation therapy nanomedicine would advance the development of targeted drug delivery system for effective RT regardless of hypoxic microenvironment.

Recent Progress in Anti-Tumor Nanodrugs Based on Tumor Microenvironment Redox Regulation

The growth state of tumor cells is strictly affected by the specific abnormal redox status of the tumor microenvironment (TME). Moreover, redox reactions at the biological level are also central and fundamental to essential energy metabolism reactions in tumors. Accordingly, anti-tumor nanodrugs targeting the disruption of this abnormal redox homeostasis have become one of the hot spots in the field of nanodrugs research due to the effectiveness of TME modulation and anti-tumor efficiency mediated by redox interference. This review discusses the latest research results of nanodrugs in anti-tumor therapy, which regulate the levels of oxidants or reductants in TME through a variety of therapeutic strategies, ultimately breaking the original "stable" redox state of the TME and promoting tumor cell death. With the gradual deepening of study on the redox state of TME and the vigorous development of nanomaterials, it is expected that more anti-tumor nano drugs based on tumor redox microenvironment regulation will be designed and even applied clinically.

Quantifying gadolinium-based nanoparticle uptake distributions in brain metastases via magnetic resonance imaging

AGuIX, a novel gadolinium-based nanoparticle, has been deployed in a pioneering double-blinded Phase II clinical trial aiming to assess its efficacy in enhancing radiotherapy for tumor treatment. This paper moves towards this goal by analyzing AGuIX uptake patterns in 23 patients. A phantom was designed to establish the relationship between AGuIX concentration and longitudinal ( T 1 ) relaxation. A 3T MRI and MP2RAGE sequence were used to generate patient T 1 maps. AGuIX uptake in tumors was determined based on longitudinal relaxivity. AGuIX (or placebo) was administered to 23 patients intravenously at 100 mg/kg 1-5 hours pre-imaging. Each of 129 brain metastases across 23 patients were captured in T 1 maps and examined for AGuIX uptake and distribution. Inferred AGuIX recipients had average tumor uptakes between 0.012 and 0.17 mg/ml, with a mean of 0.055 mg/ml. Suspected placebo recipients appeared to have no appreciable uptake. Tumors presented with varying spatial AGuIX uptake distributions, suspected to be related to differences in accumulation time and patient-specific bioaccumulation factors. This research demonstrates AGuIX's ability to accumulate in brain metastases, with quantifiable uptake via T 1 mapping. Future analyses will extend these methods to complete clinical trial data (~ 134 patients) to evaluate the potential relationship between nanoparticle uptake and possible tumor response following radiotherapy.Clinical Trial Registration Number: NCT04899908.Clinical Trial Registration Date: 25/05/2021.

Transition-Metal-Based Nanozymes: Synthesis, Mechanisms of Therapeutic Action, and Applications in Cancer Treatment

Cancer, as one of the leading causes of death worldwide, drives the advancement of cutting-edge technologies for cancer treatment. Transition-metal-based nanozymes emerge as promising therapeutic nanodrugs that provide a reference for cancer therapy. In this review, we present recent breakthrough nanozymes for cancer treatment. First, we comprehensively outline the preparation strategies involved in creating transition-metal-based nanozymes, including hydrothermal method, solvothermal method, chemical reduction method, biomimetic mineralization method, and sol-gel method. Subsequently, we elucidate the catalytic mechanisms (catalase (CAT)-like activities), peroxidase (POD)-like activities), oxidase (OXD)-like activities) and superoxide dismutase (SOD)-like activities) of transition-metal-based nanozymes along with their activity regulation strategies such as morphology control, size manipulation, modulation, composition adjustment and surface modification under environmental stimulation. Furthermore, we elaborate on the diverse applications of transition-metal-based nanozymes in anticancer therapies encompassing radiotherapy (RT), chemodynamic therapy (CDT), photodynamic therapy (PDT), photothermal therapy (PTT), sonodynamic therapy (SDT), immunotherapy, and synergistic therapy. Finally, the challenges faced by transition-metal-based nanozymes are discussed alongside future research directions. The purpose of this review is to offer scientific guidance that will enhance the clinical applications of nanozymes based on transition metals.

Enhanced Chemoradiotherapy for MRSA-Infected Osteomyelitis Using Immunomodulatory Polymer-Reinforced Nanotherapeutics

The eradication of osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA) poses a significant challenge due to its development of biofilm-induced antibiotic resistance and impaired innate immunity, which often leads to frequent surgical failure. Here, the design, synthesis, and performance of X-ray-activated polymer-reinforced nanotherapeutics that modulate the immunological properties of infectious microenvironments to enhance chemoradiotherapy against multidrug-resistant bacterial deep-tissue infections are reported. Upon X-ray radiation, the proposed polymer-reinforced nanotherapeutic generates reactive oxygen species and reactive nitrogen species. To robustly eradicate MRSA biofilms at deep infection sites, these species can specifically bind to MRSA and penetrate biofilms for enhanced chemoradiotherapy treatment. X-ray-activated nanotherapeutics modulate the innate immunity of macrophages to prevent the recurrence of osteomyelitis. The remarkable anti-infection effects of these nanotherapeutics are validated using a rat osteomyelitis model. This study demonstrates the significant potential of a synergistic chemoradiotherapy and immunotherapy method for treating MRSA biofilm-infected osteomyelitis.

Dual-vacancies modulation of 1T/2H heterostructured MoS2-CdS nanoflowers via radiolytic radical chemistry for efficient photocatalytic H2 evolution

Precise defect engineering of photocatalysts is highly demanding but remains a challenge. Here, we developed a facile and controllable γ-ray radiation strategy to assemble dual-vacancies confined MoS2-CdS-γ nanocomposite photocatalyst. We showed the solvated electron induced homogeneous growth of defects-rich CdS nanoparticles, while the symbiotic •OH radicals etched flower-like 1T/2H MoS2 substrate surfaces. The optimal MoS2-CdS-γ exhibited a H2 evolution rate of up to 37.80 mmol/h/g under visible light irradiation, which was 36.7 times higher than that of bare CdS-γ, and far superior to those synthesized by hydrothermal method. The microscopic characterizations and theoretical calculations revealed the formation of such unprecedented dual-sulfur-vacancies ensured the tight interfacial contact for fast charge separation. Besides, the existence of 1T-MoS2 phase further improved the conductivity and strengthened the adsorption interaction with H+ intermediate. Therefore, the radiolytic radical chemistry offered a facile, ambient and effective synthetic strategy to improve the catalytic performances of photocatalytic materials.

Dual-Epigenetically Relieving the MYC-Correlated Immunosuppression via an Advanced Nano-Radiosensitizer Potentiates Cancer Immuno-Radiotherapy

Cancer cells can upregulate the MYC expression to repair the radiotherapy-triggered DNA damage, aggravating therapeutic resistance and tumor immunosuppression. Epigenetic treatment targeting the MYC-transcriptional abnormality may intensively solve this clinical problem. Herein, 5-Aza (a DNA methyltransferase inhibitor) and ITF-2357 (a histone deacetylase inhibitor) are engineered into a tungsten-based nano-radiosensitizer (PWAI), to suppress MYC rising and awaken robust radiotherapeutic antitumor immunity. Individual 5-Aza depletes MYC expression but cannot efficiently awaken radiotherapeutic immunity. This drawback can be overcome by the addition of ITF-2357, which triggers cancer cellular type I interferon (IFN-I) signaling. Coupling 5-Aza with ITF-2357 ensures that PWAI does not evoke the treated model with high MYC-related immune resistance while amplifying the radiotherapeutic tumor killing, and more importantly promotes the generation of IFN-I signal-related proteins involving IFN-α and IFN-β. Unlike the radiation treatment alone, PWAI-triggered immuno-radiotherapy remarkably enhances antitumor immune responses involving the tumor antigen presentation by dendritic cells, and improves intratumoral recruitment of cytotoxic T lymphocytes and their memory-phenotype formation in 4T1 tumor-bearing mice. Downgrading the radiotherapy-induced MYC overexpression via the dual-epigenetic reprogramming strategy may elicit a robust immuno-radiotherapy.

Cuproptosis: unveiling a new frontier in cancer biology and therapeutics

Copper plays vital roles in numerous cellular processes and its imbalance can lead to oxidative stress and dysfunction. Recent research has unveiled a unique form of copper-induced cell death, termed cuproptosis, which differs from known cell death mechanisms. This process involves the interaction of copper with lipoylated tricarboxylic acid cycle enzymes, causing protein aggregation and cell death. Recently, a growing number of studies have explored the link between cuproptosis and cancer development. This review comprehensively examines the systemic and cellular metabolism of copper, including tumor-related signaling pathways influenced by copper. It delves into the discovery and mechanisms of cuproptosis and its connection to various cancers. Additionally, the review suggests potential cancer treatments using copper ionophores that induce cuproptosis, in combination with small molecule drugs, for precision therapy in specific cancer types.

Nanomedomics

Nanomaterials have attractive physicochemical properties. A variety of nanomaterials such as inorganic, lipid, polymers, and protein nanoparticles have been widely developed for nanomedicine via chemical conjugation or physical encapsulation of bioactive molecules. Superior to traditional drugs, nanomedicines offer high biocompatibility, good water solubility, long blood circulation times, and tumor-targeting properties. Capitalizing on this, several nanoformulations have already been clinically approved and many others are currently being studied in clinical trials. Despite their undoubtful success, the molecular mechanism of action of the vast majority of nanomedicines remains poorly understood. To tackle this limitation, herein, this review critically discusses the strategy of applying multiomics analysis to study the mechanism of action of nanomedicines, named nanomedomics, including advantages, applications, and future directions. A comprehensive understanding of the molecular mechanism could provide valuable insight and therefore foster the development and clinical translation of nanomedicines.

Janus ACSP Nanoparticle for Synergistic Chemodynamic Therapy and Radiosensitization

Protective autophagy and DNA damage repair lead to tumor radio-resistance. Some hypoxic tumors exhibit a low radiation energy absorption coefficient in radiation therapy. High doses of X-rays may lead to side effects in the surrounding normal tissues. In order to overcome the radio-resistance and improve the efficacy of radiotherapy based on the characteristics of the tumor microenvironment, the development of radiosensitizers has attracted much attention. In this study, a Janus ACSP nanoparticle (NP) was developed for chemodynamic therapy and radiosensitization. The reactive oxygen species generated by the Fenton-like reaction regulated the distribution of cell cycles from a radioresistant phase to a radio-sensitive phase. The high-Z element, Au, enhanced the production of hydroxyl radicals (•OH) under X-ray radiation, promoting DNA damage and cell apoptosis. The NP delayed DNA damage repair by interfering with certain proteins involved in the DNA repair signaling pathway. In vivo experiments demonstrated that the combination of the copper-ion-based Fenton-like reaction and low-dose X-ray radiation enhanced the effectiveness of radiotherapy, providing a novel approach for synergistic chemodynamic and radiosensitization therapy. This study provides valuable insights and strategies for the development and application of NPs in cancer treatment.

Reactive Oxygen Species Amplifier for Apoptosis-Ferroptosis Mediated High-Efficiency Radiosensitization of Tumors

Insufficient reactive oxygen species (ROS) production and radioresistance have consistently contributed to the failure of radiotherapy (RT). The development of a biomaterial capable of activating ROS-induced apoptosis and ferroptosis is a potential strategy to enhance RT sensitivity. To achieve precision and high-efficiency RT, the theranostic nanoplatform Au/Cu nanodots (Au/CuNDs) were designed for dual-mode imaging, amplifying ROS generation, and inducing apoptosis-ferroptosis to sensitize RT. A large amount of ROS is derived from three aspects: (1) When exposed to ionizing radiation, Au/CuNDs effectively absorb photons and emit various electrons, which can interact with water to produce ROS. (2) Au/CuNDs act as a catalase-like to produce abundant ROS through Fenton reaction with hydrogen peroxide overexpressed of tumor cells. (3) Au/CuNDs deplete overexpressed glutathione, which causes the accumulation of ROS. Large amounts of ROS and ionizing radiation further lead to apoptosis by increasing DNA damage, and ferroptosis by enhancing lipid peroxidation, significantly improving the therapeutic efficiency of RT. Furthermore, Au/CuNDs serve as an excellent nanoprobe for high-resolution near-infrared fluorescence imaging and computed tomography of tumors. The promising dual-mode imaging performance shows their potential application in clinical cancer detection and imaging-guided precision RT, minimizing damage to adjacent normal tissues during RT. In summary, our developed theranostic nanoplatform integrates dual-mode imaging and sensitizes RT via ROS-activated apoptosis-ferroptosis, offering a promising prospect for clinical cancer diagnosis and treatment.

Targeting the organelle for radiosensitization in cancer radiotherapy

Radiotherapy is a well-established cytotoxic therapy for local solid cancers, utilizing high-energy ionizing radiation to destroy cancer cells. However, this method has several limitations, including low radiation energy deposition, severe damage to surrounding normal cells, and high tumor resistance to radiation. Among various radiotherapy methods, boron neutron capture therapy (BNCT) has emerged as a principal approach to improve the therapeutic ratio of malignancies and reduce lethality to surrounding normal tissue, but it remains deficient in terms of insufficient boron accumulation as well as short retention time, which limits the curative effect. Recently, a series of radiosensitizers that can selectively accumulate in specific organelles of cancer cells have been developed to precisely target radiotherapy, thereby reducing side effects of normal tissue damage, overcoming radioresistance, and improving radiosensitivity. In this review, we mainly focus on the field of nanomedicine-based cancer radiotherapy and discuss the organelle-targeted radiosensitizers, specifically including nucleus, mitochondria, endoplasmic reticulum and lysosomes. Furthermore, the organelle-targeted boron carriers used in BNCT are particularly presented. Through demonstrating recent developments in organelle-targeted radiosensitization, we hope to provide insight into the design of organelle-targeted radiosensitizers for clinical cancer treatment.

Ultrasmall Gold Nanoparticles Radiolabeled with Iodine-125 as Potential New Radiopharmaceutical

The relatively high linear energy transfer of Auger electrons, which can cause clustered DNA damage and hence efficient cell death, makes Auger emitters excellent candidates for attacking metastasized tumors. Moreover, gammas or positrons are usually emitted along with the Auger electrons, providing the possibility of theragnostic applications. Despite the promising properties of Auger electrons, only a few radiopharmaceuticals employing Auger emitters have been developed so far. This is most likely explained by the short ranges of these electrons, requiring the delivery of the Auger emitters to crucial cell parts such as the cell nucleus. In this work, we combined the Auger emitter 125I and ultrasmall gold nanoparticles to prepare a novel radiopharmaceutical. The 125I labeled gold nanoparticles were shown to accumulate at the cell nucleus, leading to a high tumor-killing efficiency in both 2D and 3D tumor cell models. The results from this work indicate that ultrasmall nanoparticles, which passively accumulate at the cell nucleus, have the potential to be applied in targeted radionuclide therapy. Even better tumor-killing efficiency can be expected if tumor-targeting moieties are conjugated to the nanoparticles.

Synergistic anticancer effect of Pistacia lentiscus essential oils and 5-Fluorouracil co-loaded onto biodegradable nanofibers against melanoma and breast cancer

Chemoresistance and severe toxicities represent major drawbacks of chemotherapy. Natural extracts, including the essential oils of Pistacia lentiscus (PLEO), exhibit substantial anticancer and anti-inflammatory activities where different cancers are reported to dramatically recess following targeting with PLEO. PLEO has promising antimicrobial, anticancer, and anti-inflammatory properties. However, the therapeutic properties of PLEO are restricted by limited stability, bioavailability, and targeting ability. PLEO nanoformulation can maximize their physicochemical and therapeutic properties, overcoming their shortcomings. Hence, PLEO was extracted and its chemical composition was determined by GC-MS. PLEO and 5-Fluorouracil (5FU) were electrospun into poly-ε-caprolactone nanofibers (PCL-NFs), of 290.71 nm to 680.95 nm diameter, to investigate their anticancer and potential synergistic activities against triple-negative breast cancer cells (MDA-MB-231), human adenocarcinoma breast cancer cells (MCF-7), and human skin melanoma cell line (A375). The prepared nanofibers (NFs) showed enhanced thermal stability and remarkable physical integrity and tensile strength. Biodegradability studies showed prolonged stability over 42 days, supporting the NFs use as a localized therapy of breast tissues (postmastectomy) or melanoma. Release studies revealed sustainable release behaviors over 168 h, with higher released amounts of 5FU and PLEO at pH 5.4, indicating higher targeting abilities towards cancer tissues. NFs loaded with PLEO showed strong antioxidant properties. Finally, NFs loaded with either PLEO or 5FU depicted greater anticancer activities compared to free compounds. The highest anticancer activities were observed with NFs co-loaded with PLEO and 5FU. The developed 5FU-PLEO-PCL-NFs hold potential as a local treatment of breast cancer tissues (post-mastectomy) and melanoma to minimize their  possible recurrence.

Two-dimensional multifunctional nanosheets as radiosensitizers for chemodynamic/radio-therapy

The hypoxia tumor microenvironment and low radiation attenuation coefficient of tumor tissue usually limit the efficiency of radiotherapy. In this study, a two-dimensional multifunctional nano-sensitizer, CuNS@Pt, was prepared to function as a radiosensitizer, enhancing radiotherapy through multiple mechanisms. Numerous active sites were provided for the deposition of X-ray radiation energy by the in-situ chemical reduction of Pt to create functional hybrids on Cu-based nanosheets. CuNS@Pt catalyzed high concentration of endogenous hydrogen peroxide to generate oxygen in tumor microenvironment, alleviating the physiological environment of hypoxic tumors. Additionally, CuNS could reduce the content of intrinsic glutathione (GSH) and catalyze hydrogen peroxide to form hydroxyl radicals (·OH). The generated ·OH could damage mitochondria and destroy redox homeostasis due to the functional inclusion of Cu species, thereby achieving chemodynamic therapy and further improving the radiation effect. Both in vivo and in vitro experiments showed that the nano sensitizer effectively improved the therapeutic efficiency of radiotherapy and had good biological safety. All in all, this study provides a pragmatic and doable platform for maximizing the efficacy of RT in cancer. This study also highlights the future research value of two-dimensional nanomaterials.

Photonic control of image-guided ferroptosis cancer nanomedicine

Photonic nanomaterials, characterized by their remarkable photonic tunability, empower a diverse range of applications, including cutting-edge advances in cancer nanomedicine. Recently, ferroptosis has emerged as a promising alternative strategy for effectively killing cancer cells with minimizing therapeutic resistance. Novel design of photonic nanomaterials that can integrate photoresponsive-ferroptosis inducers, -diagnostic imaging, and -synergistic components provide significant benefits to effectively trigger local ferroptosis. This review provides a comprehensive overview of recent advancements in photonic nanomaterials for image-guided ferroptosis cancer nanomedicine, offering insights into their strengths, constraints, and their potential as a future paradigm in cancer treatment.

A light-controlled single-atom nanozyme hydrogels for glutathione depletion mediated low-dose radiotherapy

Due to the unique ability to mimic natural enzymes, single-atom nanoenzymes (SAE) have garnered significant attention and research in tumor therapy. However, their efficacy often faces challenges in terms of drug delivery methods, and the research regarding their applications in radiotherapy is scarce. Herein, we introduce a light-controlled SAE hydrogel platform (SH) for glutathione-depletion-mediated low-dose radiotherapy. The SH incorporates a Cu single-atom enzyme (CuSA), and upon irradiation with 1064 nm near-infrared light, the CuSA can convert light energy into heat, which in turn degrades the hydrogel, enabling the release of CuSA into tumor cells or tissues. The diffused CuSA not only can facilitate the conversion of H2O2into hydroxyl radicals (•OH), but also can effectively depletes cellular glutathione. This leads to increased sensitivity of tumor cells to radiotherapy, resulting in enhanced cytotoxicity even at low doses. The animal study results further confirmed the good tumor-killing efficacy of this SH system. To the best of our knowledge, this stands as the pioneering report on leveraging a single-atom enzyme for GSH depletion-mediated low-dose radiotherapy.

Assembling Au8 clusters on surfaces of bifunctional nanoimmunomodulators for synergistically enhanced low dose radiotherapy of metastatic tumor

BACKGROUND

Radiotherapy is one of the mainstays of cancer therapy and has been used for treating 65-75% of patients with solid tumors. However, radiotherapy of tumors has two limitations: high-dose X-rays damage adjacent normal tissue and tumor metastases cannot be prevented.

RESULTS

Therefore, to overcome the two limitations of radiotherapy, a multifunctional core-shell R837/BMS@Au8 nanoparticles as a novel radiosensitizer were fabricated by assembling Au8NCs on the surface of a bifunctional nanoimmunomodulator R837/BMS nanocore using nanoprecipitation followed by electrostatic assembly. Formed R837/BMS@Au8 NP composed of R837, BMS-1, and Au8 clusters. Au8NC can enhance X-ray absorption at the tumor site to reduce X-ray dose and releases a large number of tumor-associated antigens under X-ray irradiation. With the help of immune adjuvant R837, dendritic cells can effectively process and present tumor-associated antigens to activate effector T cells, meanwhile, a small-molecule PD-L1 inhibitor BMS-1 can block PD-1/PD-L1 pathway to reactivate cytotoxic T lymphocyte, resulting in a strong systemic antitumor immune response that is beneficial for limiting tumor metastasis. According to in vivo and in vitro experiments, radioimmunotherapy based on R837/BMS@Au8 nanoparticles can increase calreticulin expression on of cancer cells, reactive oxygen species generation, and DNA breakage and decrease colony formation. The results revealed that distant tumors were 78.2% inhibited depending on radioimmunotherapy of primary tumors. Therefore, the use of a novel radiosensitizer R837/BMS@Au8 NPs realizes low-dose radiotherapy combined with immunotherapy against advanced cancer.

CONCLUSION

In conclusion, the multifunctional core-shell R837/BMS@Au8 nanoparticles as a novel radiosensitizer effectively limiting tumor metastasis and decrease X-ray dose to 1 Gy, providing an efective strategy for the construction of nanosystems with radiosensitizing function.

Combination of biodegradable hydrogel and antioxidant bioadhesive for treatment of breast cancer recurrence and radiation skin injury

Postoperative radiotherapy is the standard method for inhibition of breast cancer recurrence and metastasis, whereas radiation resistant and ineluctable skin radiation injury are still key problems encountered in the prognosis of breast cancer. Herein, we design an internally implantable biodegradable hydrogel and extracutaneously applicable antioxidant bioadhesive to concurrently prevent postoperative tumor recurrence and radioactive skin injury after adjuvant radiotherapy. The biodegradable silk fibroin/perfluorocarbon hydrogel loading doxorubicin (DOX) formed by consecutive ultrasonication-induced β-sheets-crosslinked amphiphilic silk fibroin/perfluorocarbon/DOX nanoemulsion, exhibits continuous release of oxygen in physiological environment to improve hypoxia and sensitivity of radiotherapy, as well as simultaneous release of DOX to finally achieve effective anti-cancer effect. A stretchable bioadhesive is fabricated by copolymerization of α-thioctic acid and N, N-diacryloyl-l-lysine, and gold nanorods and gallic acid are loaded into the bioadhesive to afford gentle photothermal therapy and antioxidant functions. The near-infrared light-induced controlled release of gallic acid and mild photothermal therapy can efficiently eliminate excess free radicals generated by radiotherapy and promote radioactive wound healing. Ultimately, in vivo animal studies substantiate the efficacy of our methodology, wherein the post-tumor resection administration of hydrogel and concomitant application of an antioxidant bioadhesive patch effectively inhibit tumor recurrence and attenuate the progression of skin radiation damage.

Nanointegrative In Situ Reprogramming of Tumor-Intrinsic Lipid Droplet Biogenesis for Low-Dose Radiation-Activated Ferroptosis Immunotherapy

Low-dose radiotherapy (LDR) has shown significant implications for inflaming the immunosuppressive tumor microenvironment (TME). Surprisingly, we identify that FABP-dependent lipid droplet biogenesis in tumor cells is a key determinant of LDR-evoked cytotoxic and immunostimulatory effects and developed a nanointegrated strategy to promote the antitumor efficacy of LDR through cooperative ferroptosis immunotherapy. Specifically, TCPP-TK-PEG-PAMAM-FA, a nanoscale multicomponent functional polymer with self-assembly capability, was synthesized for cooperatively entrapping hafnium ions (Hf4+) and HIF-1α-inhibiting siRNAs (siHIF-1α). The TCPP@Hf-TK-PEG-PAMAM-FA@siHIF-1α nanoassemblies are specifically taken in by folate receptor-overexpressing tumor cells and activated by the elevated cellular ROS stress. siHIF-1α could readily inhibit the FABP3/7 expression in tumor cells via HIF-1α-FABP3/7 signaling and abolish lipid droplet biogenesis for enhancing the peroxidation susceptibility of membrane lipids, which synergizes with the elevated ROS stress in the context of Hf4+-enhanced radiation exposure and evokes pronounced ferroptotic damage in vital membrane structures. Interestingly, TCPP@Hf-TK-PEG-PAMAM-FA@siHIF-1α-enhanced ferroptotic biomembrane damage also facilitates the exposure of tumor-associated antigens (TAAs) to promote post-LDR immunotherapeutic effects, leading to robust tumor regression in vivo. This study offers a nanointegrative approach to boost the antitumor effects of LDR through the utilization of tumor-intrinsic lipid metabolism.

Gold Nanocage-Based Multifunctional Nanosensitizers for Programmed Photothermal /Radiation/Chemical Coordinated Therapy Guided by FL/MR/PA Multimodal Imaging

Background

Radiotherapy is one of the main clinical methods for the treatment of malignant tumors at present. However, its application is limited by the radiation resistance of some tumor cells and the irradiation damage to the surrounding normal tissues, and the limitation of radiotherapy dose also affects the therapeutic effect. Therefore, developing diagnostic and therapeutic agents with imaging and radiosensitizing functions is urgently needed to improve the accuracy and efficacy of radiotherapy.

Materials and Strategy

Herein, we synthesized multifunctional nanotheranostic FRNPs nanoparticles based on gold nanocages (GNCs) and MnO2 for magnetic resonance (MR)/photoacoustic (PA) imaging and combined photothermal, radiosensitive and chemical therapy. A programmed therapy strategy based on FRNPs is proposed. First, photothermal therapy is applied to ablate large tumors and increase the sensitivity of the tumor tissue to radiotherapy, then X-ray radiation is performed to further reduce the tumor size, and finally chemotherapeutic agents are used to eliminate smaller residual tumors and distant metastases.

Results

As revealed by fluorescence, MR and PA imaging, FRNPs achieved efficient aggregation and retention at tumor sites of mice after intravenous injection. In vivo studies have shown that the programmed treatment of FRNPs-injected nude mice which were exposed to X-ray after 808 laser irradiation achieved the greatest inhibition of tumor growth compared with other treatment groups. Moreover, no obvious systemic toxicity was observed in all groups of mice, indicating the good biocompatibility of FRNPs and the safety of the treatment scheme.

Conclusion

To sum up, our work not only showed a new radiosensitizer, but also provided a promising theranostic strategy for cancer treatment.

Copper homeostasis and cuproptosis in mitochondria

Mitochondria serve as sites for energy production and are essential for regulating various forms of cell death induced by metal metabolism, targeted anticancer drugs, radiotherapy and immunotherapy. Cuproptosis is an autonomous form of cell death that depends on copper (Cu) and mitochondrial metabolism. Although the recent discovery of cuproptosis highlights the significance of Cu and mitochondria, there is still a lack of biological evidence and experimental verification for the underlying mechanism. We provide an overview of how Cu and cuproptosis affect mitochondrial morphology and function. Through comparison with ferroptosis, similarities and differences in mitochondrial metabolism between cuproptosis and ferroptosis have been identified. These findings provide implications for further exploration of cuproptotic mechanisms. Furthermore, we explore the correlation between cuproptosis and immunotherapy or radiosensitivity. Ultimately, we emphasize the therapeutic potential of targeting cuproptosis as a novel approach for disease treatment.

Macrocyclic-Albumin Conjugates for Precise Delivery of Radionuclides and Anticancer Drugs to Tumors

Precise delivery of radionuclides and anticancer drugs to tumor tissue is crucial to ensuring drug synergism and optimal therapeutic effects in radionuclide-based combination radio-chemotherapy. However, current codelivery vectors often rely on physical embedment/adsorption to load anticancer drugs, which lacks precise mechanisms for drug loading and release, resulting in unpredictable combination effects. Herein, a macrocyclic-albumin conjugate (MAC) that enables precise loading and controlled release of anticancer drugs is presented. By conjugating multiple macrocyclic hosts (sulfonate azocalix[4]arenes, SAC4A) to albumin molecules, the MAC facilitates the precise loading of anticancer drugs through host-guest interactions and site-specific labeling of radionuclides. Furthermore, the MAC degrades under hypoxic conditions, enabling the release of loaded drugs upon reaching tumor tissues. Through precise loading and targeted delivery of radionuclides and anticancer drugs, MAC achieves efficient cancer diagnosis and combined radio-chemotherapy in breast cancer cell (4T1)-bearing mice. Considering that SAC4A can load many anticancer drugs, MAC may provide a promising platform for effective combination radio-chemotherapy.

Photothermal therapy of copper incorporated nanomaterials for biomedicine

Studies have reported on the significance of copper incorporated nanomaterials (CINMs) in cancer theranostics and tissue regeneration. Given their unique physicochemical properties and tunable nanostructures, CINMs are used in photothermal therapy (PTT) and photothermal-derived combination therapies. They have the potential to overcome the challenges of unsatisfactory efficacy of conventional therapies in an efficient and non-invasive manner. This review summarizes the recent advances in CINMs-based PTT in biomedicine. First, the classification and structure of CINMs are introduced. CINMs-based PTT combination therapy in tumors and PTT guided by multiple imaging modalities are then reviewed. Various representative designs of CINMs-based PTT in bone, skin and other organs are presented. Furthermore, the biosafety of CINMs is discussed. Finally, this analysis delves into the current challenges that researchers face and offers an optimistic outlook on the prospects of clinical translational research in this field. This review aims at elucidating on the applications of CINMs-based PTT and derived combination therapies in biomedicine to encourage future design and clinical translation.

Deep Insight of Design, Mechanism, and Cancer Theranostic Strategy of Nanozymes

Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007, nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity, low cost, mild reaction conditions, good stability, and suitable for large-scale production. Recently, with the cross fusion of nanomedicine and nanocatalysis, nanozyme-based theranostic strategies attract great attention, since the enzymatic reactions can be triggered in the tumor microenvironment to achieve good curative effect with substrate specificity and low side effects. Thus, various nanozymes have been developed and used for tumor therapy. In this review, more than 270 research articles are discussed systematically to present progress in the past five years. First, the discovery and development of nanozymes are summarized. Second, classification and catalytic mechanism of nanozymes are discussed. Third, activity prediction and rational design of nanozymes are focused by highlighting the methods of density functional theory, machine learning, biomimetic and chemical design. Then, synergistic theranostic strategy of nanozymes are introduced. Finally, current challenges and future prospects of nanozymes used for tumor theranostic are outlined, including selectivity, biosafety, repeatability and stability, in-depth catalytic mechanism, predicting and evaluating activities.

The Refined Application and Evolution of Nanotechnology in Enhancing Radiosensitivity During Radiotherapy: Transitioning from Gold Nanoparticles to Multifunctional Nanomaterials

Radiotherapy is a pivotal method for treating malignant tumors, and enhancing the therapeutic gain ratio of radiotherapy through physical techniques is the direction of modern precision radiotherapy. Due to the inherent physical properties of high-energy radiation, enhancing the therapeutic gain ratio of radiotherapy through radiophysical techniques inevitably encounters challenges. The combination of hyperthermia and radiotherapy can enhance the radiosensitivity of tumor cells, reduce their radioresistance, and holds significant clinical utility in radiotherapy. Multifunctional nanomaterials with excellent biocompatibility and safety have garnered widespread attention in tumor hyperthermia research, demonstrating promising potential. Utilizing nanotechnology as a sensitizing carrier in conjunction with radiotherapy, and high atomic number nanomaterials can also serve independently as radiosensitizing carriers. This synergy between tumor hyperthermia and radiotherapy may overcome many challenges currently limiting tumor radiotherapy, offering new opportunities for its further advancement. In recent years, the continuous progress in the synthesis and design of novel nanomaterials will propel the future development of medical imaging and cancer treatment. This article summarizes the radiosensitizing mechanisms and effects based on gold nanotechnology and provides an overview of the advancements of other nanoparticles (such as bismuth-based nanomaterials, magnetic nanomaterials, selenium nanomaterials, etc.) in the process of radiation therapy.

Inorganic Nanoparticles as Radiosensitizers for Cancer Treatment

Nanotechnology has expanded what can be achieved in our approach to cancer treatment. The ability to produce and engineer functional nanoparticle formulations to elicit higher incidences of tumor cell radiolysis has resulted in substantial improvements in cancer cell eradication while also permitting multi-modal biomedical functionalities. These radiosensitive nanomaterials utilize material characteristics, such as radio-blocking/absorbing high-Z atomic number elements, to mediate localized effects from therapeutic irradiation. These materials thereby allow subsequent scattered or emitted radiation to produce direct (e.g., damage to genetic materials) or indirect (e.g., protein oxidation, reactive oxygen species formation) damage to tumor cells. Using nanomaterials that activate under certain physiologic conditions, such as the tumor microenvironment, can selectively target tumor cells. These characteristics, combined with biological interactions that can target the tumor environment, allow for localized radio-sensitization while mitigating damage to healthy cells. This review explores the various nanomaterial formulations utilized in cancer radiosensitivity research. Emphasis on inorganic nanomaterials showcases the specific material characteristics that enable higher incidences of radiation while ensuring localized cancer targeting based on tumor microenvironment activation. The aim of this review is to guide future research in cancer radiosensitization using nanomaterial formulations and to detail common approaches to its treatment, as well as their relations to commonly implemented radiotherapy techniques.

Biotin-decorated hollow gold nanoshells for dual-modal imaging-guided NIR-II photothermal and radiosensitizing therapy toward breast cancer

Radiotherapy (RT) is dominantly used in breast cancer therapy but is facing fierce side effects because of the limited difference between tumor and normal tissues in response to ionizing radiation. Herein, we construct a core-shell nanoparticle of UiO-66-NH2@AuNS. Then the solid gold shell was etched into hollow AuNS (HAuNS) and further modified with biotin-PEG-SH (PEG-bio) to obtain HAuNS@PEG-bio. HAuNS@PEG-bio demonstrates effective near infrared II (NIR-II) region photothermal therapy (PTT) performance, and the increase of temperature at the tumor site promotes the blood circulation to alleviate the hypoxia in the tumor microenvironment (TME). Meanwhile, HAuNS exhibits strong X-ray absorption and deposition ability due to the high atomic coefficient of elemental Au (Z = 79) and hollowed-out structure. Through the dual radiosensitization of the high atomic coefficient of Au and the hypoxia alleviation from PTT of HAuNS, the breast cancer cells could undergo immunogenic cell death (ICD) to activate the immune response. At the in vivo level, HAuNS@PEG-bio performs NIR-II photothermal, radiosensitization, and ICD therapies through cellular targeting, guided by infrared heat and CT imaging. This work highlights that the constructed biotin-decorated hollow gold nanoshell has a promising potential as a diagnostic and treatment integration reagents for the breast cancer.

One Stone, Three Birds: Multifunctional Nanodots as "Pilot Light" for Guiding Surgery, Enhanced Radiotherapy, and Brachytherapy of Tumors

Surgery, radiotherapy (RT), and brachytherapy are crucial treatments for localized deep tumors. However, imprecise tumor location often leads to issues such as positive surgical margins, extended radiotherapy target volumes, and radiation damage to healthy tissues. Reducing side effects in healthy tissue and enhancing RT efficacy are critical challenges. To address these issues, we developed a multifunctional theranostic platform using Au/Ag nanodots (Au/AgNDs) that act as a "pilot light" for real-time guided surgery, high-efficiency RT, and brachytherapy, achieving a strategy of killing three birds with one stone. First, dual-mode imaging of Au/AgNDs enabled precision RT, minimizing damage to adjacent normal tissue during X-ray irradiation. Au/AgNDs enhanced ionizing radiation energy deposition, increased intracellular reactive oxygen species (ROS) generation, regulated the cell cycle, promoted DNA damage formation, and inhibited DNA repair in tumor cells, significantly improving RT efficacy. Second, in brachytherapy, precise guidance provided by dual-mode imaging addressed challenges related to non-visualization of existing interstitial brachytherapy and multiple adjustments of insertion needle positions. Meanwhile, the effect of brachytherapy was improved. Third, the excellent fluorescence imaging of Au/AgNDs accurately distinguished tumors from normal tissue, facilitating their use as a powerful tool for assisting surgeons during tumor resection. Taken together, our multifunctional theranostic platform offers real-time guidance for surgery and high-efficiency RT, and improves brachytherapy precision, providing a novel strategy and vision for the clinical diagnosis and treatment of cancer.

A Multifunctional Covalent Organic Framework Nanozyme for Promoting Ferroptotic Radiotherapy against Esophageal Cancer

Radiotherapy is inevitably accompanied by some degree of radiation resistance, which leads to local recurrence and even therapeutic failure. To overcome this limitation, herein, we report the room-temperature synthesis of an iodine- and ferrocene-loaded covalent organic framework (COF) nanozyme, termed TADI-COF-Fc, for the enhancement of radiotherapeutic efficacy in the treatment of radioresistant esophageal cancer. The iodine atoms on the COF framework not only exerted a direct effect on radiotherapy, increasing its efficacy by increasing X-ray absorption, but also promoted the radiolysis of water, which increased the production of reactive oxygen species (ROS). In addition, the ferrocene surface decoration disrupted redox homeostasis by increasing the levels of hydroxyl and lipid peroxide radicals and depleting intracellular antioxidants. Both in vitro and in vivo experiments substantiated the excellent radiotherapeutic response of TADI-COF-Fc. This study demonstrates the potential of COF-based multinanozymes as radiosensitizers and suggests a possible treatment integration strategy for combination oncotherapy.

Cuproptosis: Harnessing Transition Metal for Cancer Therapy

Transition metal elements, such as copper, play diverse and pivotal roles in oncology. They act as constituents of metalloenzymes involved in cellular metabolism, function as signaling molecules to regulate the proliferation and metastasis of tumors, and are integral components of metal-based anticancer drugs. Notably, recent research reveals that excessive copper can also modulate the occurrence of programmed cell death (PCD), known as cuprotosis, in cancer cells. This modulation occurs through the disruption of tumor cell metabolism and the induction of proteotoxic stress. This discovery uncovers a mode of interaction between transition metals and proteins, emphasizing the intricate link between copper homeostasis and tumor metabolism. Moreover, they provide innovative therapeutic strategies for the precise diagnosis and treatment of malignant tumors. At the crossroads of chemistry and oncology, we undertake a comprehensive review of copper homeostasis in tumors, elucidating the molecular mechanisms underpinning cuproptosis. Additionally, we summarize current nanotherapeutic approaches that target cuproptosis and provide an overview of the available laboratory and clinical methods for monitoring this process. In the context of emerging concepts, challenges, and opportunities, we emphasize the significant potential of nanotechnology in the advancement of this field.

Glycerol-weighted chemical exchange saturation transfer nanoprobes allow 19F/1H dual-modality magnetic resonance imaging-guided cancer radiotherapy

Recently, radiotherapy (RT) has entered a new realm of precision cancer therapy with the introduction of magnetic resonance (MR) imaging guided radiotherapy systems into the clinic. Nonetheless, identifying an optimized radiotherapy time window (ORTW) is still critical for the best therapeutic efficacy of RT. Here we describe pH and O2 dual-sensitive, perfluorooctylbromide (PFOB)-based and glycerol-weighted chemical exchange saturation transfer (CEST) nano-molecular imaging probes (Gly-PFOBs) with dual fluorine and hydrogen proton based CEST MR imaging properties (19F/1H-CEST). Oxygenated Gly-PFOBs ameliorate tumor hypoxia and improve O2-dependent radiotherapy. Moreover, the pH and O2 dual-sensitive properties of Gly-PFOBs could be quantitatively, spatially, and temporally monitored by 19F/1H-CEST imaging to optimize ORTW. In this study, we describe the CEST signal characteristics exhibited by the glycerol components of Gly-PFOBs. The pH and O2 dual-sensitive Gly-PFOBs with19F/1H-CEST MR dual-modality imaging properties, with superior therapeutic efficacy and biosafety, are employed for sensitive imaging-guided lung cancer RT, illustrating the potential of multi-functional imaging to noninvasively monitor and enhance RT-integrated effectiveness.

Tumor microenvironment-responsive DNA-based nanomedicine triggers innate sensing for enhanced immunotherapy

Lack of proper innate sensing inside the tumor microenvironment could reduce both innate and adaptive immunity, which remains a critical cause of immunotherapy failure in various tumor treatments. Double-stranded DNA (dsDNA) has been evidenced to be a promising immunostimulatory agent to induce type I interferons (IFN-Is) production for innate immunity activation through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway, yet the unsatisfactory delivery and susceptibility to nuclease degradation hindered its feasibility for further clinical applications. Herein, we report on the constructed tumor microenvironment-responsive DNA-based nanomedicine loaded by dendritic mesoporous organosilica nanoparticles (DMONs), which provide efficient delivery of dsDNA to induce intratumoral IFN-Is production for triggering innate sensing for enhanced anti-tumor immunotherapy. Extensive in vitro and in vivo evaluations have demonstrated the dramatic IFN-Is production induced by dsDNA@DMONs in both immune cells and tumor cells, which facilitates dendritic cells (DCs) maturation and T cells activation for eliciting the potent innate immune and adaptive immune responses. Desirable biosafety and marked therapeutic efficacy with a tumor growth inhibition (TGI) of 51.0% on the murine B16-F10 melanoma model were achieved by the single agent dsDNA@DMONs. Moreover, dsDNA@DMONs combined with anti-PD-L1 antibody further enhanced the anti-tumor efficacy and led to almost complete tumor regression. Therefore, this work highlighted the immunostimulatory DNA-based nanomedicine as a promising strategy for overcoming the resistance to immunotherapy, by promoting the IFN-Is production for innate immunity activation and remodeling the tumor microenvironment.

Gold Nanoparticles Enhance the Ability of Radiotherapy to Induce Immunogenic Cell Death in Glioblastoma

Background

Radiation therapy (RT) is commonly used to treat glioblastoma, but its immunomodulatory effect on tumors, through mechanisms such as immunogenic cell death (ICD), is relatively weak. Gold nanoparticles (AuNPs) have been suggested as potential radio-sensitizers, but it is unclear if they can enhance radiation-induced ICD. This study aimed to investigate the potential of AuNPs to improve the effectiveness of radiation-induced ICD.

Methods

G422 cells were treated with a combination of AuNPs and RT to induce cell death. Various assays were conducted to assess cell death, surface expression of CRT, and release of HMGB1 and ATP. In vitro co-culture experiments with bone marrow-derived dendritic cells (BMDCs) were performed to analyze the immunogenicity of dying cancer cells. Flow cytometry was used to measure the maturation rate of BMDCs. An in vivo mouse tumor prophylactic vaccination model was employed to assess immunogenicity.

Results

The study findings presented here confirm that the combination of radiotherapy (RT) with AuNPs can induce a stronger ICD effect on glioblastoma cells compared to using RT alone. Specifically, treatment with AuNPs combined with RT resulted in the emission of crucial damage-associated molecular patterns (DAMPs) such as CRT, HMGB1 (479.41±165.34pg/mL vs 216.04±178.16 pg/mL, *P<0.05) and ATP (The release of ATP in the AuNPs + RT group was 1.2 times higher than in the RT group, *P<0.05). The proportion of BMDC maturation rate was higher in the group treated with AuNPs and RT compared to the group treated with RT alone. (32.53±0.52% vs 25.03±0.28%,***P < 0.001). In the tumor vaccine experiment, dying tumor cells treated with AuNPs and RT effectively inhibited tumor growth in mice when exposed to living tumor cells.

Conclusion

These results indicate that AuNPs have the ability to enhance RT-induced ICD.

Myoglobin-loaded gadolinium nanotexaphyrins for oxygen synergy and imaging-guided radiosensitization therapy

Gadolinium (Gd3+)-coordinated texaphyrin (Gd-Tex) is a promising radiosensitizer that entered clinical trials, but temporarily fails largely due to insufficient radiosensitization efficacy. Little attention has been given to using nanovesicles to improve its efficacy. Herein, Gd-Tex is transformed into building blocks "Gd-Tex-lipids" to self-assemble nanovesicles called Gd-nanotexaphyrins (Gd-NTs), realizing high density packing of Gd-Tex in a single nanovesicle and achieving high Gd-Tex accumulation in tumors. To elucidate the impact of O2 concentration on Gd-Tex radiosensitization, myoglobin (Mb) is loaded into Gd-NTs (Mb@Gd-NTs), resulting in efficient relief of tumor hypoxia and significant enhancement of Gd-Tex radiosensitization, eventually inducing the obvious long-term antitumor immune memory to inhibit tumor recurrence. In addition to Gd3+, the versatile Mb@Gd-NTs can also chelate 177Lu3+ (Mb@177Lu/Gd-NTs), enabling SPECT/MRI dual-modality imaging for accurately monitoring drug delivery in real-time. This "one-for-all" nanoplatform with the capability of chelating various trivalent metal ions exhibits broad clinical application prospects in imaging-guided radiosensitization therapy.

Multifunctional Au@AgBiS2 Nanoparticles as High-Efficiency Radiosensitizers to Induce Pyroptosis for Cancer Radioimmunotherapy

Radiotherapy (RT), a widely used clinical treatment modality for cancer, uses high-energy irradiation for reactive oxygen species (ROS) production and DNA damage. However, its therapeutic effect is primarily limited owing to insufficient DNA damage to tumors and harmful effects on normal tissues. Herein, a core-shell structure of metal-semiconductors (Au@AgBiS2 nanoparticles) that can function as pyroptosis inducers to both kill cancer cells directly and trigger a robust anti-tumor immune against 4T1 triple-negative murine breast cancer and metastasis is rationally designed. Metal-semiconductor composites can enhance the generation of considerable ROS and simultaneously DNA damage for RT sensitization. Moreover, Au@AgBiS2 , a pyroptosis inducer, induces caspase-3 protein activation, gasdermin E cleavage, and the release of damage-associated molecular patterns. In vivo studies in BALB/c mice reveal that Au@AgBiS2 nanoparticles combined with RT exhibit remarkable antitumor immune activity, preventing tumor growth, and lung metastasis. Therefore, this core-shell structure is an alternative for designing highly effective radiosensitizers for radioimmunotherapy.

Bismuth-based two-dimensional nanomaterials for cancer diagnosis and treatment

The intrinsic high X-ray attenuation and insignificant biological toxicity of Bi-based nanomaterials make them a category of advanced materials in oncology. Bi-based two-dimensional nanomaterials have gained rapid development in cancer diagnosis and treatment owing to their adjustable bandgap structure, high specific surface area and strong NIR absorption. In addition to the single functional cancer diagnosis and treatment modalities, Bi-based two-dimensional nanomaterials have been certified for accomplishing multi-imaging guided multifunctional synergistic cancer therapies. In this review, we summarize the recent progress including controllable synthesis, defect engineering and surface modifications of Bi-based two-dimensional nanomaterials for cancer diagnosis and treatment in the past ten years. Their medical applications in cancer imaging and therapies are also presented. Finally, we discuss the potential challenges and future research priorities of Bi-based two-dimensional nanomaterials.

A Cancer Cell Selective Replication Stress Nano Amplifier Promotes Replication Fork Catastrophe to Overcome Radioresistance

Replication stress (RS) induced by DNA damage plays a significant role in conferring the anticancer effects of radiotherapy and is tightly associated with radioresistance of cancer cells. Amplification of RS represents an effective approach to improving the efficacy of radiotherapy, although the development of selective RS amplifiers remains an unexplored frontier. We herein present an RS nano amplifier (RSNA) consisting of a catalytic FePt nanoparticle loaded with the chemotherapeutic doxorubicin (DOX), which selectively exacerbates RS in cancer cells by promoting replication fork (RF) catastrophe. RSNA converts the excessive reactive oxygen species (ROS) in cancer cells into oxygen, enhancing the DNA-damaging effects of radiotherapy to create more template lesions that impede RF progression in coalition with DOX. After radiation, ROS scavenging by RSNA accelerates RF progression through damaged template strands, increasing the frequency of RF collapse into double-strand breaks. Moreover, pretreatment with RSNA accumulates cancer cells in the S phase, exposing more RFs to radiation-induced RS. These effects of RSNA convergently maximize RS in cancer cells, effectively overcoming the radioresistance of cancer cells without affecting normal cells. Our study demonstrates the feasibility of selectively amplifying RS to boost radiotherapy.

Evaluation of a photodynamic therapy agent using a canine prostate cancer model

BACKGROUND

Male dogs can develop spontaneous prostate cancer, which is similar physiologically to human disease. Recently, Tweedle and coworkers have developed an orthotopic canine prostate model allowing implanted tumors and therapeutic agents to be tested in a more translational large animal model. We used the canine model to evaluate prostate-specific membrane antigen (PSMA)-targeted gold nanoparticles as a theranostic approach for fluorescence (FL) imaging and photodynamic therapy (PDT) of early stage prostate cancer.

METHODS

Dogs (four in total) were immunosuppressed with a cyclosporine-based immunosuppressant regimen and their prostate glands were injected with Ace-1-hPSMA cells using transabdominal ultrasound (US) guidance. Intraprostatic tumors grew in 4-5 weeks and were monitored by ultrasound (US). When tumors reached an appropriate size, dogs were injected intravenously (iv) with PSMA-targeted nano agents (AuNPs-Pc158) and underwent surgery 24 h later to expose the prostate tumors for FL imaging and PDT. Ex vivo FL imaging and histopathological studies were performed to confirm PDT efficacy.

RESULTS

All dogs had tumor growth in the prostate gland as revealed by US. Twenty-four hours after injection of PSMA-targeted nano agents (AuNPs-Pc158), the tumors were imaged using a Curadel FL imaging device. While normal prostate tissue had minimal fluorescent signal, the prostate tumors had significantly increased FL. PDT was activated by irradiating specific fluorescent tumor areas with laser light (672 nm). PDT bleached the FL signal, while fluorescent signals from the other unexposed tumor tissues were unaffected. Histological analysis of tumors and adjacent prostate revealed that PDT damaged the irradiated areas to a depth of 1-2 mms with the presence of necrosis, hemorrhage, secondary inflammation, and occasional focal thrombosis. The nonirradiated areas showed no visible damages by PDT.

CONCLUSION

We have successfully established a PSMA-expressing canine orthotopic prostate tumor model and used the model to evaluate the PSMA-targeted nano agents (AuNPs-Pc158) in the application of FL imaging and PDT. It was demonstrated that the nano agents allowed visualization of the cancer cells and enabled their destruction when they were irradiated with a specific wavelength of light.

Tellurium-driven maple leaf-shaped manganese nanotherapeutics reshape tumor microenvironment via chemical transition in situ to achieve highly efficient radioimmunotherapy of triple negative breast cancer

The therapeutic efficacy of radioimmunotherapy against triple negative breast cancer (TNBC) is largely limited by the complicated tumor microenvironment (TME) and its immunosuppressive state. Thus developing a strategy to reshape TME is expected to achieve highly efficient radioimmunotherapy. Therefore, we designed and synthesized a tellurium (Te)-driven maple leaf manganese carbonate nanotherapeutics (MnCO3@Te) by gas diffusion method, but also provided a chemical catalytic strategy in situ to augment ROS level and activate immune cells for improving cancer radioimmunotherapy. As expected, with the help of H2O2 in TEM, MnCO3@Te heterostructure with reversible Mn3+/Mn2+ transition could catalyze the intracellular ROS overproduction to amplify radiotherapy. In addition, by virtue of the ability to scavenge H+ in TME by carbonate group, MnCO3@Te directly promote the maturation of dendritic cells and macrophage M1 repolarization by stimulator of interferon genes (STING) pathway activation, resulting in remodeling immuno-microenvironment. As a result, MnCO3@Te synergized with radiotherapy and immune checkpoint blockade therapy effectively inhibited the breast cancer growth and lung metastasis in vivo. Collectively, these findings indicate that MnCO3@Te as an agonist, successfully overcome radioresistance and awaken immune systems, showing promising potential for solid tumor radioimmunotherapy.

Precise Engineering of a Se/Te Nanochaperone for Reinvigorating Cancer Radio-Immunotherapy

Facilely synthesized nanoradiosensitizers with well-controlled structure and multifunctionality are greatly desired to address the challenges of cancer radiotherapy. In this work, a universal method is developed for synthesizing chalcogen-based TeSe nano-heterojunctions (NHJs) with rod-, spindle-, or dumbbell-like morphologies by engineering the surfactant and added selenite. Interestingly, dumbbell-shaped TeSe NHJs (TeSe NDs) as chaperone exhibit better radio-sensitizing activities than the other two nanostructural shapes. Meanwhile, TeSe NDs can serve as cytotoxic chemodrugs that degrade to highly toxic metabolites in acidic environment and deplete GSH within tumor to facilitate radiotherapy. More importantly, the combination of TeSe NDs with radiotherapy significantly decreases regulatory T cells and M2-phenotype tumor-associated macrophage infiltrations within tumors to reshape the immunosuppressive microenvironment and induce robust T lymphocytes-mediated antitumor immunity, resulting in great abscopal effects on combating distant tumor progression. This study provides a universal method for preparing NHJ with well-controlled structure and developing nanoradiosensitizers to overcome the clinical challenges of cancer radiotherapy.