Emerging Strategies of Nanomaterial-Mediated Tumor Radiosensitization

Pursuing theranostics: a multimodal architecture approach

Theranostics is a field of nuclear medicine which uses the same targeting vector and chelating system for both a diagnostic and therapeutic radionuclide, allowing for uniformity in imaging and treatment. This growing field requires the development of more flexible chelate systems that permit novel targeting strategies. Toward this end, a multimodal architecture has been realized, making use of a phosphazene-based core and click chemistry to achieve a flexible and customizable scaffold. The six arm phosphazene-based core can scaffold six DTPA chelating motifs or a mixed set of 3 : 3 DTPA : DFO chelates resulting in two multimodal compounds, pDbDt and pDbDtDf, respectively. Terbium complexes displayed strong luminescence, supporting that the structures act as an organic antenna for luminescence. Metal displacement titration studies confirmed the desired structures as well as the capability for heterometallic labeling of the structures. These structures were found to have high thermal and biological stability in vitro. Radiolabeling of each compound resulted in high molar activity labeling of each compound: 169 MBq nmol-1: [161Tb]Tb-pDbDt, 170 MBq nmol-1: [89Zr]Zr-pDbDtDf, and the mixed radiolabeling illustrated chelation of both radionuclides in a 1 : 1 ratio. This multimodal architecture is promising as a heterometallic structure for coupling of both a diagnostic and a therapeutic radionuclide with a highly customizable core structure.

X-ray triggered bimetallic nanoassemblies as radiosensitizers and STING agonists for a CDT/radio-immunotherapy strategy

Radiotherapy (RT) is a cornerstone of cancer therapy, but its effectiveness is constrained by dose-limiting toxicity and inadequate systemic immune activation. To overcome these limitations, we have engineered an X-ray-responsive nanoassembly (sMnAu NAs) by cross-linking monodisperse MnAu nanoparticles (NPs) with radiation-responsive diselenide-containing linkers. MnAu alloy NPs not only provide Au NPs for radiosensitization, but also control Mn (0) release, which stimulates Fenton-like reaction for chemodynamic therapy and is transferred into Mn2+ to activate the STING pathway for immunotherapy. The responsive design not only improves tumor accumulation via EPR effect during circulation, but also achieves deep penetration of MnAu NPs following X-ray induced disassembly. The synergistic combination of chemodynamic therapy, radiotherapy and immunotherapy exhibits remarkable inhibition of tumor growth and metastasis. Overall, our sMnAu NAs represent a promising radiosensitizer for chemodynamic therapy and radiotherapy to enhance immunotherapy. STATEMENT OF SIGNIFICANCE: As a principal treatment modality in cancer management, RT is limited due to the co-irradiation of organs at risk and subsequent normal tissue toxicities. This study reported an X-ray responsive radiosensitizer prepared by cross-linking monodisperse MnAu NPs with diselenide-containing linkers. Upon X-ray irradiation, sMnAu NAs accumulate in tumors and disassemble into MnAu NPs, enabling deeper penetration. The increased surface area of MnAu NPs enhances the exposure of Mn(0), which reacts into Mn2+ and enhances ROS generation. The released Mn2+ activates the STING pathway, potentiating the X-ray-induced immune response. The synergistic integration of CDT, RT, and immunotherapy results in a potent suppression of tumor growth and metastasis. Collectively, this X-ray activatable CDT/radio-immunotherapy strategy holds great potential for effective cancer treatment.

X-ray-Triggered Activation of Polyprodrugs for Synergistic Radiochemotherapy

X-ray-induced photodynamic therapy (XPDT) can penetrate deeply into the tumor tissues to overcome the disadvantage of conventional PDT. However, the therapeutic efficacy of XPDT in cancer therapy is still restricted due to the insufficient reactive oxygen species (ROS) generation at a relatively low irradiation dosage. Herein, we present the tumor pH and ROS-responsive polyprodrug micelles to load the X-ray photosensitizer verteporfin (VP) as an ROS production enhancer. The block copolymer polyprodrug consisting of hydrophilic poly(ethylene glycol) (PEG) as well as the segments of thioketal-linked camptothecin (CPT) methacrylate (CPTKMA) and 2-(pentamethyleneimino)ethyl methacrylate (PEMA) (PEG-b-P(CPTKMA-co-PEMA)) can self-assemble into micelles in aqueous solution and encapsulate VP with a high loading efficiency of 67%. Inside tumor tissues, the zeta potential of the micelles can transform from neutral to positive for promoted cellular internalization under tumor acidity. Followed by X-ray irradiation at the dose of 4 Gy, efficient ROS generation in the presence of VP triggers CPT release. The VP-loaded polyprodrug micelles can finally ablate tumors efficiently via synergistic radiochemotherapy due to deep penetration of X-ray inside tumor tissues, ROS generation enhancement, and triggered CPT release. Consequently, this promising strategy represents a robust therapeutic modality for the enhanced radiochemotherapy of cancers.

Multifunctional Cu3BiS3-BP@PEI Radiosensitizer with Enhanced Reactive Oxygen Species Activity for Multimodal Synergistic Therapy

Development of radiosensitizers with high-energy deposition efficiency, electron transfer, and oxidative stress amplification will help to improve the efficiency of radiotherapy. To overcome the drawbacks of radiotherapy alone, it is also crucial to design a multifunctional radiosensitizer that simultaneously realizes multimodal treatment and tumor microenvironment modulation. Herein, a multifunctional radiosensitizer based on the Cu3BiS3-BP@PEI nanoheterostructure (NHS) for multimodal cancer treatment is designed. Cu3BiS3-BP@PEI NHS is able to deposit a high radiation dose into cancer cells, enhancing the radiotherapy effect. Due to the heterostructure and the synergistic effect of Cu3BiS3 and black phosphorus (BP), significantly boosted 1O2 and •OH generation is obtained under X-ray irradiation, which is promising for extremely efficient radiodynamic therapy. More importantly, the acidic tumor microenvironment (TME) can induce the cycle conversion of Cu2+ to Cu+, oxidizing glutathione (GSH) and catalyzing intracellular overproduction of H2O2 into highly toxic •OH, which thus further enhances reactive oxygen species (ROS) production and reduces GSH-associated radioresistance. Furthermore, Cu3BiS3-BP@PEI NHS has an excellent photothermal effect and can effectively transform light into heat. The outcomes of the in vitro and in vivo research confirm that the as-prepared Cu3BiS3-BP@PEI NHS has a high synergistic therapeutic efficacy at a low radiation dose. This work provides a viable approach to constructing a multifunctional radiosensitizer for deep tumor treatment with TME-triggered multiple synergistic therapies.

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.

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.

Advances in nanotechnology-based approaches for the treatment of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), one of the most common types of cancers occurring in the head and neck region, is often associated with high mortality rates due to its invasiveness and morbidity. The mainstream treatment methods in clinical settings, including surgery, chemotherapy, and radiotherapy, may cause poor overall survival rate and prognosis, with issues such as drug resistance, damage to adjacent healthy tissues, and potential recurrences. Other treatment approaches such as immunotherapy, photodynamic therapy (PDT), and photothermal therapy (PPT) also suffer from inefficient tumor targeting and suboptimal therapeutic outcomes. Early detection is vital for HNSCC patients, but it is always limited by insensitivity and confusing clinical manifestations. Hence, it is highly desirable to develop optimized therapeutic and diagnostic strategies. With the boom in nanomaterials, nanotechnology-conducted HNSCC therapy has attracted widespread attention. Nanoparticles (NPs) are distinguished by their unique morphology and superior physicochemical property, and some can exhibit direct antitumor activity, while others serve as promising candidates for drug delivery. In addition, NPs offer the potential for structural modification for drug delivery and tumor targeting, enabling specific delivery to tumor cells through conjugation with biomarker ligands and improving cargo biocompatibility. This work reviews current therapies and diagnosis methods for HNSCC, highlights the characteristics of the major NPs, surveys their uses and advantages in the treatment of HNSCC, and discusses the obstacles and prospects in clinical applications, aiming to enlighten future research directions for nanotechnology-based therapy for HNSCC.

Glutathione-Depleted Photodynamic Nanoadjuvant for Triggering Nonferrous Ferroptosis to Amplify Radiotherapy of Breast Cancer

Radiotherapy plays a crucial role in the treatment of advanced breast cancer, but the increased antioxidant system, especially the rise in glutathione (GSH), presents a significant obstacle to its effectiveness. To address this challenge, a versatile GSH-depleted photodynamic nanoadjuvant is developed to augment the efficacy of radiotherapy for breast cancer treatment. This nanoadjuvant operates within the tumor microenvironment to effectively deplete intracellular GSH through a sequence of cascaded processes, including GSH exhaustion, biosynthetic inhibition, and photodynamic oxidation. This leads to a notable accumulation of lipid peroxides (LPO) and subsequent suppression of glutathione peroxidase 4 (GPX4) activity. Consequently, the combined GSH depletion induced by the nanoadjuvant markedly promotes nonferrous ferroptosis, thereby contributing to the augmentation of antitumor efficiency during radiotherapy in breast cancer. This work presents an innovative approach to designing and synthesizing biocompatible nanoadjuvants with the goal of improving the efficacy of radiotherapy for breast cancer in prospective clinical scenarios.

Recent Advances in Silica-Based Nanomaterials for Enhanced Tumor Imaging and Therapy

Cancer remains a formidable challenge, inflicting profound physical, psychological, and financial burdens on patients. In this context, silica-based nanomaterials have garnered significant attention for their potential in tumor imaging and therapy owing to their exceptional properties, such as biocompatibility, customizable porosity, and versatile functionalization capabilities. This review meticulously examines the latest advancements in the application of silica-based nanomaterials for tumor imaging and therapy. It underscores their potential in enhancing various cancer imaging modalities, including fluorescence imaging, magnetic resonance imaging, computed tomography, positron emission tomography, ultrasound imaging, and multimodal imaging approaches. Moreover, the review delves into their therapeutic efficacy in chemotherapy, radiotherapy, phototherapy, immunotherapy, gas therapy, sonodynamic therapy, chemodynamic therapy, starvation therapy, and gene therapy. Critical evaluations of the biosafety profiles and degradation pathways of these nanomaterials within biological environments are also presented. By discussing the current challenges and prospects, this review aims to provide a nuanced perspective on the clinical translation of silica-based nanomaterials, thereby highlighting their promise in revolutionizing cancer diagnostics, enabling real-time monitoring of therapeutic responses, and advancing personalized medicine.

Nanotechnology in healthcare, and its safety and environmental risks

Nanotechnology holds immense promise in revolutionising healthcare, offering unprecedented opportunities in diagnostics, drug delivery, cancer therapy, and combating infectious diseases. This review explores the multifaceted landscape of nanotechnology in healthcare while addressing the critical aspects of safety and environmental risks associated with its widespread application. Beginning with an introduction to the integration of nanotechnology in healthcare, we first delved into its categorisation and various materials employed, setting the stage for a comprehensive understanding of its potential. We then proceeded to elucidate the diverse healthcare applications of nanotechnology, spanning medical diagnostics, tissue engineering, targeted drug delivery, gene delivery, cancer therapy, and the development of antimicrobial agents. The discussion extended to the current situation surrounding the clinical translation and commercialisation of these cutting-edge technologies, focusing on the nanotechnology-based healthcare products that have been approved globally to date. We also discussed the safety considerations of nanomaterials, both in terms of human health and environmental impact. We presented the in vivo health risks associated with nanomaterial exposure, in relation with transport mechanisms, oxidative stress, and physical interactions. Moreover, we highlighted the environmental risks, acknowledging the potential implications on ecosystems and biodiversity. Lastly, we strived to offer insights into the current regulatory landscape governing nanotechnology in healthcare across different regions globally. By synthesising these diverse perspectives, we underscore the imperative of balancing innovation with safety and environmental stewardship, while charting a path forward for the responsible integration of nanotechnology in healthcare.

Nanozymes as Glucose Scavengers and Oxygenerators for Enhancing Tumor Radiotherapy

Insufficient accumulation of reactive oxygen species (ROS) due to tumor hypoxia significantly contributes to increased radiation resistance and the failure of radiotherapy (RT). Therefore, developing methods to alleviate hypoxia and boost ROS levels represents a promising strategy for enhanced radiosensitivity. This study introduced a self-cascade catalytic Pt@Au nanozymes as a radiosensitizer, using glucose oxidase (GOx)-, catalase (CAT)-, and peroxidase (POD)-like activities to improve hypoxia and increase ROS accumulation, thereby affecting glucose metabolism and enhancing the effects of RT. Pt@Au nanozymes exhibit GOx-like activity, which not only depletes glucose to induce starvation therapy, but also generates hydrogen peroxide (H2O2) for cascade reactions. Moreover, Pt@Au nanozymes demonstrate CAT-like activity, catalyzing the conversion of H2O2 to O2. This conversion effectively alleviates hypoxia, stabilizes ROS, increases DNA damage, significantly enhancing RT efficacy and sustaining the effects of starvation therapy. As high-Z materials, Pt@Au nanozymes can deposit more X-ray energy. Furthermore, the POD-like activity catalyzes the conversion of H2O2 into highly reactive hydroxyl radicals (·OH), which increases ROS levels and enhances RT. Pt@Au nanozymes serve as X-ray computed tomography (CT) imaging agents, allowing for clear differentiation between tumor and normal tissue boundaries and enhancing the precision of RT. In summary, Pt@Au nanozymes serve as effective radiosensitizers by depleting glucose to induce starvation therapy, enhancing cascade reactions, and inhibiting tumor proliferation. Through their self-cascade reactions, these nanozymes dramatically increase oxygen levels within tumors, reduce hypoxia, and enhance ROS levels. This advancement addresses the radioresistance associated with hypoxic tumors, paving the way for innovative strategies in RT.

PU-H71 (NSC 750424): a molecular masterpiece that targets HSP90 in cancer and beyond

Heat shock protein 90 (HSP90) is a pivotal molecular chaperone with multifaceted roles in cellular health and disease. Herein, we explore how HSP90 orchestrates cellular stress responses, particularly through its partnership with heat shock factor 1 (HSF-1). PU-H71, a selective inhibitor of HSP90, demonstrates significant potential in cancer therapy by targeting a wide array of oncogenic pathways. By inducing the degradation of multiple client proteins, PU-H71 disrupts critical signaling pathways such as MAPK, PI3K/Akt, JAK/STAT, EGFR, and mTOR, which are essential for cancer cell survival, proliferation, and metastasis. We examined its impact on combating triple-negative breast cancer and enhancing the effectiveness of carbon-ion beam therapy, offering new avenues for cancer treatment. Furthermore, the dual inhibition of HSP90A and HSP90B1 by PU-H71 proves highly effective in the context of myeloma, providing fresh hope for patients with this challenging malignancy. We delve into its potential to induce apoptosis in B-cell lymphomas that rely on Bcl6 for survival, highlighting its relevance in the realm of hematologic cancers. Shifting our focus to hepatocellular carcinoma, we explore innovative approaches to chemotherapy. Moreover, the current review elucidates the potential capacity of PU-H71 to suppress glial cell activation paving the way for developing novel therapeutic strategies for neuroinflammatory disorders. Additionally, the present report also suggests the promising role of PU-H71 in JAK2-dependent myeloproliferative neoplasms. Eventually, our report sheds more light on the multiple functions of HSP90 protein as well as the potential therapeutic benefit of its selective inhibitor PU-H71 in the context of an array of diseases, laying the foundations for the development of novel therapeutic approaches that could achieve better treatment outcomes.

Nanomaterials for the Diagnosis and Treatment of Triple-Negative Breast Cancer

In recent years, the diagnosis and treatment at the early stages significantly raise the survival rate of breast cancer patients. Moreover, antibody drugs pave the way toward precision target therapy. However, the treatment and survival of triple-negative breast cancer (TNBC) patients is still worrying, which needs further understanding and study. During the last several years, nanomaterials attracted extensive research interests in TNBC diagnosis and therapy. In this review, we summarize recent advances of nanomaterial-based strategies for diagnosing and treating TNBC. Specifically, treatments for TNBC utilizing nanomaterials are classified into monotherapy, combined therapy, and multimodal therapy based on the complexity of the treatment. Nanomaterials also offer the opportunity to integrating diagnosis with treatment, which are introduced and summarized in this review. By summarizing the design principles in detail, some insights into the challenges and opportunities are provided to inspire further research and clinical translation in this field. The scope of this review is to summarize the development of nanomaterials for diagnosis and treatment of TNBC, and to discuss future directions to improve the clinical outcome of TNBC patients.

Intelligent Hydrogel-Assisted Hepatocellular Carcinoma Therapy

Given the high malignancy of liver cancer and the liver's unique role in immune and metabolic regulation, current treatments have limited efficacy, resulting in a poor prognosis. Hydrogels, soft 3-dimensional network materials comprising numerous hydrophilic monomers, have considerable potential as intelligent drug delivery systems for liver cancer treatment. The advantages of hydrogels include their versatile delivery modalities, precision targeting, intelligent stimulus response, controlled drug release, high drug loading capacity, excellent slow-release capabilities, and substantial potential as carriers of bioactive molecules. This review presents an in-depth examination of hydrogel-assisted advanced therapies for hepatocellular carcinoma, encompassing small-molecule drug therapy, immunotherapy, gene therapy, and the utilization of other biologics. Furthermore, it examines the integration of hydrogels with conventional liver cancer therapies, including radiation, interventional therapy, and ultrasound. This review provides a comprehensive overview of the numerous advantages of hydrogels and their potential to enhance therapeutic efficacy, targeting, and drug delivery safety. In conclusion, this review addresses the clinical implementation of hydrogels in liver cancer therapy and future challenges and design principles for hydrogel-based systems, and proposes novel research directions and strategies.

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.

pH-sensitive and redox-responsive poly(tetraethylene glycol) nanoparticle-based platform for cancer treatment

Effective drug delivery with precise tumour targeting is crucial for cancer treatment. To address the challenges posed by the specificity and complexity of the tumour microenvironment, we developed a poly(tetraethylene glycol)-based disulfide nanoparticle (NP) platform and explored its potential in cancer treatment, focusing on drug loading and controlled release performance. Poly(tetraethylene glycol) NPs were characterised using nuclear magnetic resonance spectroscopy, mass spectrometry, and ultraviolet-visible spectroscopy. Additionally, we evaluated physicochemical properties, including dynamic light scattering, zeta potential analysis, drug loading capacity (DLC), and drug loading efficiency (DLE). The impact of NPs on the mouse colorectal cancer cell line (CT26) and NIH3T3 cells was assessed using a cytotoxicity assay, live/dead staining assay, flow cytometry, and confocal fluorescence microscopy. The experimental results align with the expected chemical structure and physicochemical properties of poly(tetraethylene glycol) NPs. These NPs exhibit high DLE (78.7%) and DLC (12%), with minimal changes in particle size over time in different media.In vitroexperiments revealed that the NPs can induce significant cytotoxicity and apoptosis in CT26 cells. Cellular uptake notably increases with increasing concentration and exposure time. The confocal microscopic analysis confirmed the effective distribution and accumulation of NPs within cells. In conclusion, poly(tetraethylene glycol) NPs hold promise for improving drug-delivery efficiency, offering potential advancements in cancer treatment.

Beyond aromatherapy: can essential oil loaded nanocarriers revolutionize cancer treatment?

Cancer, a complex global health burden, necessitates the development of innovative therapeutic strategies. While chemotherapy remains the primary treatment approach, its severe side effects and chemoresistance drive the search for novel alternatives. Essential oils (EOs), consisting of diverse bioactive phytochemicals, offer promise as anticancer agents. However, their limitations, such as instability, limited bioavailability, and non-specific targeting, hinder their therapeutic potential. These challenges were circumvented by utilizing nanoparticles and nanosystems as efficient delivery platforms for EOs. This review highlights the accumulating evidence based on loading EOs into several nanocarriers, including polymeric nanoparticles, nanoemulsions, nanofibers, lipid-based nanocapsules and nanostructures, niosomes, and liposomes, as effective anticancer regimens. It covers extraction and chemical composition of EOs, their mechanisms of action, and targeting strategies to various tumors. Additionally, it delves into the diverse landscape of nanocarriers, including their advantages and considerations for cancer targeting and EO encapsulation. The effectiveness of EO-loaded nanocarriers in cancer targeting and treatment is examined, highlighting enhanced cellular uptake, controlled drug release, and improved therapeutic efficacy. Finally, the review addresses existing challenges and future perspectives, emphasizing the potential for clinical translation and personalized medicine approaches.

Nanoradiosensitizers in glioblastoma treatment: recent advances and future perspectives

Glioblastoma (GBM), a highly invasive type of brain tumor located within the central nervous system, manifests a median survival time of merely 14.6 months. Radiotherapy kills tumor cells through focused high-energy radiation and has become a crucial treatment strategy for GBM, especially in cases where surgical resection is not viable. However, the presence of radioresistant tumor cells limits its clinical effectiveness. Radioresistance is a key factor of treatment failure, prompting the development of various therapeutic strategies to overcome this challenge. With the rapid development of nanomedicine, nanoradiosensitizers provide a novel approach to enhancing the effectiveness of radiotherapy. In this review, we discuss the reasons behind GBM radio-resistance and the mechanisms of radiotherapy sensitization. Then we summarize the primary types of nanoradiosensitizers and recent progress in their application for the radiosensitization of GBM. Finally, we elucidate the factors influencing their practical implementation, along with the challenges and promising prospects associated with multifunctional nanoradiosensitizers.

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.

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.