Nanoscale metal-organic frameworks for mitochondria-targeted radiotherapy-radiodynamic therapy

Unlocking the in vivo therapeutic potential of radiation-activated photodynamic therapy for locally advanced rectal cancer with lymph node involvement

BACKGROUND

Rectal cancer is a leading cause of cancer-related mortality worldwide. The recurrence of locally advanced rectal cancer (LARC), particularly in cases involving lymph node-positive tumours, remains a critical challenge in rectal cancer management. In this study, a therapeutic strategy, radiation-activated photodynamic therapy (RA-PDT), for the treatment of LARC with lymph node-positive tumours was developed and evaluated.

METHODS

RA-PDT was achieved by using a lipid-polymer hybrid nanoplatform loaded with verteporfin (VP) and functionalised with folic acid (FA) as a targeting molecule. Upon receiving a single 4 Gy fraction of radiation, VP was effectively activated, generating sufficient reactive oxygen species (ROS) to induce cancer cell death-however surrounding tissue was less affected and was spared. The efficacy of this strategy was assessed through in vitro cytotoxicity studies in HCT116 cells, as well as in orthotopic and subcutaneous mouse models. In vivo lymph node tumour progression was also evaluated.

FINDINGS

RA-PDT effectively generated ROS following 4 Gy irradiation and exhibited significant cytotoxicity in HCT116 cells. In vivo, this strategy largely inhibited primary tumour growth in both orthotopic and subcutaneous mouse models while also suppressing lymph node tumour progression. Surrounding tissues were minimally affected, highlighting the precision and safety of this approach.

INTERPRETATION

RA-PDT demonstrates potential as a safe therapeutic strategy for LARC, paving the way for its clinical translation.

FUNDING

This study was supported by the Australian National Health and Medical Research Council (GNT1181889), fellowship award (2019/CDF1013) from Cancer Institute NSW, Australia, the Australian Research Council Centre of Excellence for Nanoscale Biophotonics (CE140100003), UNSW SHARP funding, project grant from National Foundation for Medical Research and Innovation, Australia, International Research Training Program Scholarship (IRTP) from Australian Government, PhD Research Scholar Award from Sydney Vital Translational Cancer Research, and Translational Cancer Research Network PhD Scholarship Top-up award.

Hafnium Metal-Organic Framework-Based Glutamine Metabolism Disruptor For Potentiating Radio-Immunotherapy in MYC-Amplified Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) with MYC oncogene amplification remains a serious challenge in clinical practice. Recent advances in comprehensive treatment strategies, particularly the combination of radiotherapy and immunotherapy, offer new hope. To further improve efficacy while lowering radiation doses, nanopharmaceuticals based on high-Z elements have been extensively studied in radio-immunotherapy. In this work, a hafnium-based metal-organic framework (Hf-MOF), UiO-66-Hf(2OH)-CB-839/BSO@HA (UiO-66-Hf(2OH)-C/B@HA), was designed to codeliver telaglenastat (CB-839) and buthionine sulfoximine (BSO), which synergistically inhibited glutamine metabolism and alleviated tumor hypoxia. Further modification with hyaluronic acid (HA) enhanced tumor targeting, ultimately strengthening the efficacy of radiotherapy in MYC-amplified HCC. Beyond increasing reactive oxygen species (ROS) generation, promoting DNA damage, and inducing tumor apoptosis, more importantly, UiO66-Hf(2OH)-C/B@HA triggered immunogenic cell death (ICD), driving the antitumor immune response. Combination with immune checkpoint blockade (ICB) further enhanced the efficacy, accompanied by increased infiltration of T cells with high granzyme B expression (GZMB+ T cells) within the tumor microenvironment (TME). In the orthotopic HCC model, established with MYC-amplified tumor cells, intravenous administration of UiO66-Hf(2OH)-C/B@HA significantly potentiated the efficacy of radio-immunotherapy, resulting in superior tumor regression. In summary, our study provides insights into the design of Hf-MOF for radio-immunotherapy and proposes a promising therapeutic approach for MYC-amplified HCC.

Emerging magic bullet: subcellular organelle-targeted cancer therapy

The therapeutic efficacy of anticancer drugs heavily relies on their concentration and retention at the corresponding target site. Hence, merely increasing the cellular concentration of drugs is insufficient to achieve satisfactory therapeutic outcomes, especially for the drugs that target specific intracellular sites. This necessitates the implementation of more precise targeting strategies to overcome the limitations posed by diffusion distribution and nonspecific interactions within cells. Consequently, subcellular organelle-targeted cancer therapy, characterized by its exceptional precision, have emerged as a promising approach to eradicate cancer cells through the specific disruption of subcellular organelles. Owing to several advantages including minimized dosage and side effect, optimized efficacy, and reversal of multidrug resistance, subcellular organelle-targeted therapies have garnered significant research interest in recent years. In this review, we comprehensively summarize the distribution of drug targets, targeted delivery strategies at various levels, and sophisticated strategies for targeting specific subcellular organelles. Additionally, we highlight the significance of subcellular targeting in cancer therapy and present essential considerations for its clinical translation.

A rhodamine-coordinated iridium complex to overcome cisplatin-resistant cancer via regulating mitochondrial function triggered apoptosis and ferroptosis

Modulating mitochondrial activity to regulate cancer cell homeostatic recycling presents a promising approach to overcome tumor resistance. Consequently, there is an urgent need for novel mitochondria-targeting agents and innovative strategies. We have developed [((η5-Cp∗)Ir(rhod)]2+2PF6- (Ir-rhod), a new mitochondria-targeted iridium complex that exhibits greater cytotoxicity towards A549R (cisplatin-resistant human lung cancer) cells compared to the ligand rhod. Ir-rhod's mitochondrial targeting ability stems from both rhodamine's inherent mitochondrial affinity and the complex's positive bivalent nature. The positively charged Ir-rhod enters cells and is drawn to mitochondria due to the high transmembrane potential in tumor cells. Notably, rhodamine enables real-time observation of Ir-rhod's dynamic distribution in vivo. Ir-rhod influences mitochondrial function, triggering tumor cell ferroptosis and apoptosis by modulating ACSL4 and GPX4. The targeting effect of Ir-rhod reduces its systemic toxicity in vivo, enhancing its biosafety profile. To our knowledge, Ir-rhod is an effective mitochondria-targeted Ir complex capable of inducing tumor cell death by disrupting mitochondrial function, offering a potent strategy to suppress cisplatin resistance in non-small cell lung cancer.

Defect-Rich BiO₂₋x-BP Composite Nanoplatform: A Synergistic Approach for X-Ray and Near-Infrared-Enhanced Cancer Radiodynamic Therapy

Cancer treatment faces significant challenges, including hypoxia within the tumor microenvironment, which limits the efficacy of conventional therapies. This study introduces a multifunctional nanoplatform comprising defect-rich BiO₂₋x and black phosphorus (BP) nanosheets to address this issue. BiO₂₋x effectively catalyzes the decomposition of tumor-overexpressed H₂O₂ into oxygen, mitigating hypoxia. Its high atomic number enhances X-ray absorption, increasing local radiation doses. When combined with BP, BiO₂₋x forms a heterojunction that produces secondary electrons, generating reactive oxygen species (ROS) like ·OH under X-ray irradiation. Additionally, under 808 nm near-infrared (NIR) light, the platform exhibits strong photothermal effects, further enhancing cancer cell apoptosis. In vitro and in vivo experiments demonstrate the nanoplatform's remarkable ability to synergize radiotherapy, photothermal therapy, and radiodynamic therapy, resulting in significant tumor suppression without adverse effects on major organs. This innovative approach highlights the potential of BiO₂₋x-BP composites for addressing hypoxia and achieving multimodal cancer therapy.

Hafnium-Doped Prussian Blue Nanoparticles with Homologous Tumor Targeting and Magnetic Resonance Imaging Ability for Enhanced Tumor Radiotherapy via Photothermal Therapy and Hypoxia Relief

Radiotherapy (RT) continues to encounter significant obstacles such as formidable resistance, potential harm to adjacent healthy cells, and restricted effectiveness against tumors, resulting in a notable recurrence rate. Therefore, combining imaging, other treatments, and suitable enzyme activity in one nanoplatform can enhance the RT effect and reduce the damage to normal tissue. In this study, integrating hafnium in Prussian blue (PB) nanoparticles (PB NPs) provided innovative hafnium-doped PB (HPB) NPs as multifunctional radiosensitizers. The HPB NPs were enveloped by the cancer cell membrane, resulting in cancer cell membrane-camouflaged HPB (CMHPB) NPs that can specifically target homologous tumors. Moreover, owing to the inherent ability of photothermal therapy (PTT), magnetic resonance imaging (MRI), and catalase (CAT)-like activity of PB NPs, CMHPB NPs effectively overcome tumor hypoxia and realize the MRI-guided combined RT and PTT. The prepared HPB NPs possessed uniform and cubic morphology with a monodisperse size of approximately 80 nm and T1 MRI capability (r1 = 0.9309 mM-1 S-1). The HPB NPs showed reliable PTT efficiency and CAT-like activity in vitro and in vivo. Guided by MRI, the CMHPB NPs can be precisely delivered to the tumor region for combined RT and PTT for targeted destruction of tumor cells, significantly inhibiting tumor growth. The innovative multifunctional CMHPB NPs can be used for MRI-guided RT and PTT, which address the key challenges of RT and provide a viable strategy for enhancing tumor treatment.

Recent Progress in Radiosensitive Nanomaterials for Radiotherapy-Triggered Drug Release

Benefiting from the unique properties of ionizing radiation, such as high tissue penetration, spatiotemporal resolution, and clinical relevance compared with other external stimuli, radiotherapy-induced drug release strategies are showing great promise in developing effective and personalized cancer treatments. However, the requirement of high doses of X-ray irradiation to break chemical bonds for drug release limits the application of radiotherapy-induced prodrug activation in clinics. Recent advances in nanomaterials offer a promising approach for radiotherapy sensitization as well as integrating multiple modalities for improved therapy outcomes. In particular, the catalytic radiosensitization that utilizes electrons and energy generated by nanomaterials upon X-ray irradiation has demonstrated excellent potential for enhanced radiotherapy. In this Review, we summarize the design principles of X-ray-responsive chemical bonds for controlled drug release, strategies for catalytic radiosensitization, and recent progress of X-ray-responsive nanoradiosensitizers for enhanced radiotherapy by integration with chemotherapy, chemodynamic therapy, photodynamic therapy, photothermal therapy, gas therapy, and immunotherapy. Finally, we discuss the challenges of X-ray-responsive nanoradiosensitizers heading toward possible clinical translation. We expect that emerging strategies based on radiotherapy-triggered drug release will facilitate a frontier in accurate and effective cancer therapy in the near future.

Biomimetic polymeric nanoreactors with photooxidation-initiated therapies and reinvigoration of antigen-dependent and antigen-free immunity

Immune cell-mediated anticancer modalities usually suffer from immune cell exhaustion and limited efficacy in solid tumors. Herein, the oxygen-carrying biomimetic nanoreactors (BNR2(O2)) have been developed with photooxidation-driven therapies and antigen-dependent/antigen-free immune reinvigoration against xenograft tumors. The BNR2(O2) composes polymeric nanoreactors camouflaged with cancer cell membranes can efficiently target homotypic tumors. It continuously releases O2 to boost intracellular reactive oxygen species (ROS) to oxide diselenide bonds, which controllably releases seleninic acids and anti-folate Pemetrexed compared to hydrogen peroxide and glutathione incubation. The O2-rich microenvironment sensitizes Pemetrexed and blocks programmed cell-death ligand 1 (PD-L1) to reverse T cell immunosuppression. The ROS and Pemetrexed upregulate pro-apoptosis proteins and inhibit folate-related enzymes, which cause significant apoptosis and immunogenic cell death to stimulate dendritic cell maturation for improved secretion of cytokines, expanding antigen-dependent T cell immunity. Furthermore, by regulating the release of seleninic acids, the checkpoint receptor human leukocyte antigen E of tumor cells can be blocked to reinvigorate antigen-free natural killer cell immunity. This work offers an advanced antitumor strategy by bridging biomimetic nanoreactors and modulation of multiple immune cells.

Recent advances and design strategies for organic afterglow agents to enhance autofluorescence-free imaging performance

Long-lasting afterglow luminescence imaging that detects photons slowly being released from chemical defects has emerged, eliminating the need for real-time photoexcitation and enabling autofluorescence-free in vivo imaging with high signal-to-background ratios (SBRs). Organic afterglow nano-systems are notable for their tunability and design versatility. However, challenges such as unsatisfactory afterglow intensity, short emission wavelengths, limited activatable strategies, and shallow tissue penetration depth hinder their widespread biomedical applications and clinical translation. Such contradiction between promising prospects and insufficient properties has spurred researchers' efforts to improve afterglow performance. In this review, we briefly outline the general composition and mechanisms of organic afterglow luminescence, with a focus on design strategies and an in-depth understanding of the structure-property relationship to advance afterglow luminescence imaging. Furthermore, pending issues and future perspectives are discussed.

KMO-driven metabolic reconfiguration and its impact on immune cell infiltration in nasopharyngeal carcinoma: a new avenue for immunotherapy

BACKGROUND

Nasopharyngeal carcinoma (NPC), a malignant epithelial tumor, is characterized by a complex tumor microenvironment (TME) and closely associated with metabolic dysfunction. Mitochondrial metabolism plays a crucial role in supporting the rapid proliferation of tumor cells. However, the specific response of mitochondria to the NPC microenvironment and their role in regulating the metabolic heterogeneity of the tumor remain poorly understood.

METHODS

Tissue samples and corresponding clinicopathological data were collected from 72 primary NPC patients and 36 non-tumor controls. Histological analysis, coupled with public transcriptomic database interrogation, was utilized to investigate mitochondrial dynamics and metabolism across different cell types. Characterizing the interactions within the tumor-immune microenvironment (TME), we identified mitochondrial genes associated with prognosis in NPC. Additionally, we explored the relationship between key mitochondrial genes, the TME, and the response to immunotherapy.

RESULTS

Malignant epithelial cells in NPC exhibited altered mitochondrial metabolism, including dysregulation of amino acid and glucose metabolism, when compared to non-malignant cells. The mitochondrial-related hub gene KMO was significantly downregulated in NPC tissues relative to normal controls. Low expression of KMO was associated with poorer survival outcomes in patients. Furthermore, KMO expression was negatively correlated with DNA repair mechanisms and hypoxia. In addition, KMO levels were inversely associated with the upregulation of both oxidative phosphorylation (OXPHOS) and glycolysis pathways within the NPC tumor microenvironment (TME). Single-cell transcriptomic analysis revealed that KMO was primarily expressed in B cells, with some contribution from myeloid cells. Importantly, KMO levels positively correlated with the infiltration of various immune cell populations, including B cells, T cells, and macrophages, as well as inflammatory signatures. Further investigation indicated that individuals with elevated KMO expression may exhibit heightened sensitivity to immune checkpoint blockade (ICB) therapy compared to those with lower KMO expression.

CONCLUSION

The mitochondrial hub gene KMO plays a pivotal role in regulating mitochondrial metabolism and modulating the immune microenvironment in NPC. As a potential prognostic biomarker, KMO may offer valuable predictive insights, and targeting KMO could represent a promising therapeutic strategy for NPC, potentially enhancing the efficacy of immunotherapies.

Ru-Ph Nanozyme-Based Hydrogels for Tumor Chemodynamic Therapy by Enhancing Enzyme Catalytic Efficiency Through Multiple Pathways

The discovery of nanozymes has opened new possibilities for tumor therapy. However, their reliance on the tumor microenvironment and limited catalytic efficiency hinder broader applications. In this study, ruthenium-phenanthroline nanoparticles (Ru-Phs) are synthesized by combining ruthenium with phenanthroline and subsequently coloaded with the proton pump inhibitor (PPI) pantoprazole into sodium alginate (ALG) to form a Ru-Phs-PPI-ALG hydrogel for in situ tumor therapy. This hydrogel demonstrates excellent chemodynamic properties, forming a gel within tumor tissues and gradually releasing Ru-Phs, which generates highly toxic reactive oxygen species (ROS) via peroxidase-like (POD-like) activity. The inclusion of PPI reduced the intracellular pH of tumor cells, accelerating the Fenton reaction and ROS accumulation. Additionally, the high photothermal conversion efficiency of Ru-Phs-PPI-ALG enables heat generation under near-infrared (NIR) irradiation, which not only disrupts tumor cell structures but also further enhances the POD-like catalytic activity of Ru-Phs. The hydrogel effectively killed 4T1 cells in vitro, and transcriptomic analysis confirms its potent chemodynamic efficacy. In vivo experiments demonstrate significant tumor ablation and excellent biocompatibility. This multipathway strategy to increase enzyme activity and improve chemodynamic effects provides a promising approach for advancing nanozyme applications in tumor therapy.

Trojan-horse inspired nanoblaster: X-ray triggered spot attack on radio-resistant cancer through radiodynamic therapy

Radiotherapy as a mainstay of in-depth cervical cancer (CC) treatment suffers from its radioresistance. Radiodynamic therapy (RDT) effectively reverses radio-resistance by generating reactive oxygen species (ROS) with deep tissue penetration. However, the photosensitizers stimulated by X-ray have high toxicity and energy attenuation. Therefore, X-ray responsive diselenide-bridged mesoporous silica nanoparticles (DMSNs) are designed, loading X-ray-activated photosensitizer acridine orange (AO) for spot blasting RDT like Trojan-horse against radio-resistance cervical cancer (R-CC). DMSNs can encapsulate a large amount of AO, in the tumor microenvironment (TME), which has a high concentration of hydrogen peroxide, X-ray radiation triggers the cleavage of diselenide bonds, leading to the degradation of DMSNs and the consequent release of AO directly at the tumor site. On the one hand, it solves the problems of rapid drug clearance, adverse distribution, and side effects caused by simple AO treatment. On the other hand, it fully utilizes the advantages of highly penetrating X-ray responsive RDT to enhance radiotherapy sensitivity. This approach results in ROS-induced mitochondria damage, inhibition of DNA damage repair, cell cycle arrest and promotion of cancer cell apoptosis in R-CC. The X-ray responsive DMSNs@AO hold considerable potential in overcoming obstacles for advanced RDT in the treatment of R-CC.

The Road Ahead for Metal-Organic Frameworks: Current Landscape, Challenges and Future Prospects

This perspective highlights the transformative potential of Metal-Organic Frameworks (MOFs) in environmental and healthcare sectors. It discusses work that has advanced beyond technology readiness levels of >4 including applications in capture, storage, and conversion of gases to value added products. This work showcases efforts in the most salient applications of MOFs which have been performed at a great cadence, enabled by the federal government, large companies, and startups to commercialize these technologies despite facing significant challenges. This article also forecasts the role of nanoscale MOFs in healthcare, including strides toward personalized medicine, advocating for their use in custom-tailored drug delivery systems. Finally we underscore the potential acceleration in MOF research and development through the integration of machine learning and AI, positioning MOFs as versatile tools poised to address global sustainability and health challenges.

Recent Updates on the Efficacy of Mitocans in Photo/Radio-therapy for Targeting Metabolism in Chemo/Radio-resistant Cancers: Nanotherapeutics

Conventional therapeutic modalities against the cancers such as surgery, chemotherapy (CT) and radiotherapy (RT) have limited efficacy due to drug resistance, and adverse effects. Recent developments in nanoscience emphasized novel approaches to overcome the aforementioned limitations and subsequently improve overall clinical outcomes in cancer patients. Photodynamic therapy (PDT), photothermal therapy (PTT), and radiodynamic therapy (RDT) can be used as cancer treatments due to their high selectivity, low drug resistance, and low toxicity. Mitocans are the therapeutic molecules that can produce anti-cancer effects by modulating mitochondria functions and they have significant implications in cancer therapy. Mitochondria- targeted therapy is a promising strategy in cancer treatment as these organelles play a crucial function in the regulation of apoptosis and metabolism in tumor cells and are more vulnerable to hyperthermia and oxidative damage. The aim of this review is used to explore the targeting efficacy of mitocans in the nanotherapeutic formulation when combined with therapies like PDT, PTT, RDT. We searched several databases include Pubmed, relemed, scopus, google scholar, Embase and collected the related information to the efficacy of mitocans in nanotherapeutics when combined with photo-radiotherapy to target chemo/radio-resisant tumor cells. In this review, we vividly described research reports pertinent to the selective delivery of chemotherapy molecules into specific sub-organelles which can significantly improve the efficiency of cancer treatment by targeting tumor cell metabolism. Furthermore, the rational design, functionalization and application of various mitochondrial targeting units, including organic phosphine/sulfur salts, quaternary ammonium salts, transition metal complexes, and mitochondria-targeted cancer therapy such as PDT, PTT, RDT, and others were summarized. Mainly, the efficacy of these modalities against mtDNA and additional nanotherapeutic strategies with photosensitizers, or radiotherapy to target mitochondrial metabolism in tumor cells with chemo/radio-resistance were delineated. This review can benefit nanotechnologists, oncologists, and radiation oncologists to develop rational designs and application of novel mitochondrial targeting drugs mainly to target metabolism in chemo/radio-resistant cancer cells in cancer therapy.

Amplifying Radiotherapy by Evoking Mitochondrial Oxidative Stress using a High-performance Aggregation-induced Emission Sonosensitizer

INTRODUCTION

Developing effective methods to enhance tumor radiosensitivity is crucial for improving the therapeutic efficacy of radiotherapy (RT). Due to its deep tissue penetration, excellent safety profile, and precise controllability, sonosensitizer-based sonodynamic therapy (SDT) has recently garnered significant attention as a promising combined approach with RT.

METHODS

However, the limited reactive oxygen species (ROS) generation ability in the aggregated state and the absence of specific organelle targeting in sonosensitizers hinder their potential to augment RT. This study introduces a fundamental principle guiding the design of high-performance sonosensitizers employed in the aggregated state. Building upon these principles, we develop a mitochondria-targeted sonosensitizer molecule (TCSVP) with aggregation- induced emission (AIE) characteristics by organic synthesis. Then, we demonstrate the abilities of TCSVP to target mitochondria and produce ROS under ultrasound in H460 cancer cells using confocal laser scanning microscopy (CLSM) and fluorescence microscopy. Subsequently, we examine the effectiveness of enhancing tumor radiosensitivity by utilizing TCSVP and ultrasound in both H460 cells and H460 and 4T1 tumor-bearing mice.

RESULTS

The results indicate that evoking non-lethal mitochondrial oxidative stress in tumors by TCSVP under ultrasound stimulation can significantly improve tumor radiosensitivity (p <0.05). Additionally, the in vivo safety profile of TCSVP is thoroughly confirmed by histopathological analysis.

CONCLUSION

This work proposes strategies for designing efficient sonosensitizers and underscores that evoking non-lethal mitochondrial oxidative stress is an effective method to enhance tumor radiosensitivity.

Intelligent Pyroptosis Inducer for Precise and Augmented Tumor Therapy Through Specific Activation Pyroptosis in Tumor

Pyroptosis inducer, a powerful anti-tumor agent that causes obvious programmed cell death and immune stimulation, has been challenged to trigger specific pyroptotic tumor cell death while keeping pyroptosis silence in normal cells. Here, an intelligent inducer is reported that acts as a reactive oxygen species (ROS) scavenger in normal cells to keep pyroptosis silence, while serving as ROS generator to induce obvious pyroptotic tumor cells death dependent on high hydrogen peroxide levels and near-infrared laser irradiation. This switchable activity ensures this inducer to precisely kill the tumor cells with augmented immunogenicity while causing minimal damage to normal cells. Moreover, the catalase-like activity endows this inducer to overcome limitation of tumor hypoxia on ROS generation and show significant pyroptosis activation, further initiating the immune response to inhibit the tumor metastases in vivo. This study provides valuable insights into design new pyroptosis inducer with controllable pyroptosis activity to specifically induce programmed tumor cell pyroptosis for precise and augmented tumor therapy with minimal side effects.

Nanomaterial-based regulation of redox metabolism for enhancing cancer therapy

Altered redox metabolism is one of the hallmarks of tumor cells, which not only contributes to tumor proliferation, metastasis, and immune evasion, but also has great relevance to therapeutic resistance. Therefore, regulation of redox metabolism of tumor cells has been proposed as an attractive therapeutic strategy to inhibit tumor growth and reverse therapeutic resistance. In this respect, nanomedicines have exhibited significant therapeutic advantages as intensively reported in recent studies. In this review, we would like to summarize the latest advances in nanomaterial-assisted strategies for redox metabolic regulation therapy, with a focus on the regulation of redox metabolism-related metabolite levels, enzyme activity, and signaling pathways. In the end, future expectations and challenges of such emerging strategies have been discussed, hoping to enlighten and promote their further development for meeting the various demands of advanced cancer therapies. It is highly expected that these therapeutic strategies based on redox metabolism regulation will play a more important role in the field of nanomedicine.

Multimodal Photodynamic Therapy by Inhibiting the Nrf2/ARE Signaling Pathway in Tumors

Photodynamic therapy (PDT) has been widely used in the clinical therapy of various tumors, especially superficial tumors. However, the tumor microenvironment presents hypoxia, as well as the inherent antioxidant system (e.g., Nrf2) of tumor cells limits the therapeutic outcomes. Herein, a cascade-responsive "oxidative stress amplifier" (named EZ@TD) is designed by encapsulating manganese-doped carbon dots acting as a photosensitizer and catalase (CAT)-like nanozyme within pH-sensitive ZIF-8 and Zn2+-activated DNAzyme for relieving hypoxia and efficient Nrf2 gene disruption to enhance PDT. It is demonstrated that EZ@TD synergistically inhibited tumor growth and activated the antitumor immune response by inhibiting the Nrf2/ARE signaling pathway in tumors. We provide a new paradigm for amplifying intracellular oxidative stress by interfering with various signaling pathways.

Achieving Efficient X-ray Scintillation of Purely Organic Phosphorescent Materials by Chromophore Confinement

Scintillators have attracted significant attention due to their wide-ranging applications in both industrial and medical fields. However, one of the ongoing challenges is the efficient utilization of triplet excitons to achieve high radioluminescence efficiency. Here, a series of purely organic phosphors is presented for X-ray scintillation, employing a combined rigid and flexible host-guest doping strategy. The doped crystals exhibit a remarkable maximum phosphorescence efficiency of 99.4% under UV excitation. Furthermore, upon X-ray irradiation, the radioluminescence intensities of the doped phosphors are markedly higher compared to their single-component crystal counterparts. Through systematic investigations, it is demonstrated the crucial role of confining isolated chromophores in enhancing scintillation efficiency. Additionally, a transparent scintillator screen fabricated with the doped phosphor exhibits excellent X-ray imaging performance, achieving a high spatial resolution of 18.0 lp mm-1. This work not only offers valuable insights into suppressing non-radiative transitions of triplet excitons during scintillation but also opens a new avenue for designing highly efficient purely organic phosphorescent scintillators.

Applications of Metal-Organic Frameworks (MOFs) in Drug Delivery, Biosensing, and Therapy: A Comprehensive Review

The porous materials known as metal-organic frameworks (MOFs) stand out for their enormous surface area, adaptable pore size and shape, and structural variety. These characteristics make them well-suited for various applications, especially in healthcare. This review thoroughly summarizes recent studies on the use of MOFs in drug delivery, biosensing, and therapeutics. MOFs may encapsulate medications, target certain cells or tissues, and regulate their release over time. Additionally, MOFs have the potential to be used in biosensing applications, allowing for the selective detection of chemical and biological substances. MOFs' optical or electrical characteristics may be modified to make biosensors that track physiological data. MOFs show potential for targeted drug delivery and the regulated release of therapeutic substances in cancer treatment. In addition, they may work as potent antibacterial agents, providing a less dangerous option than traditional antibiotics that increase antibiotic resistance. For practical applications, further research is required as well as more consideration for the problems with toxicity and biocompatibility. In addition to addressing the difficulties and promising possibilities in this area, this study intends to provide insights into the potential of MOFs in healthcare for drug delivery, biosensing, and treatment. Despite several essential reviews in this area, it was necessary to look into the most recent research on drug delivery, biosensing, and therapy as a combined concept.

Mitochondria-Targeted Gold Biometallization for Photoacoustically Visualized Photothermal Cancer Therapy

Subcellular biomineralization systems with cellular intervention functions have shown great potential in cancer theranostic applications. However, the lack of subcellular specificity, high ion concentrations, and long incubation time required for biomineralization still limit its in vivo therapeutic efficacy. Herein, we report a mitochondria-targeted polymer-gold complex (TPPM-Au) to realize mitochondrial biometallization, which involves analogous mechanisms during biomineralization, for cancer treatment in vivo. The TPP-containing TPPM-Au delivered more Au3+ selectively into the mitochondria of cancer cells than normal cells, rapidly mineralizing to gold nanoparticles (GNPs) and consuming a large amount of the antioxidant glutathione (GSH). The formed GNPs can further continue consuming GSH with the atomic economy by forming Au-S with GSH, which further results in the accumulation of reactive oxygen species (ROS), thereby impairing mitochondrial function and inducing cell apoptosis. More importantly, TPPM-Au is capable of having superior tumor-penetrating, excellent photothermal and photoacoustic properties, endowing it with the ability to inhibit tumor growth through spatiotemporally monitorable mitochondria-targeted biometallization and photothermal therapy. The mitochondria-targeted gold biometallization theranostic platform provides insight into the application of subcellularly targeted biometallization or biomineralization in cancer therapy.

Targeted mitochondrial nanomaterials in biomedicine: Advances in therapeutic strategies and imaging modalities

Mitochondria, pivotal organelles crucial for energy generation, apoptosis regulation, and cellular metabolism, have spurred remarkable advancements in targeted material development. This review surveys recent breakthroughs in targeted mitochondrial nanomaterials, illuminating their potential in drug delivery, disease management, and biomedical imaging. This review approaches from various application perspectives, introducing the specific applications of mitochondria-targeted materials in cancer treatment, probes and imaging, and diseases treated with mitochondria as a therapeutic target. Addressing extant challenges and elucidating potential therapeutic mechanisms, it also outlines future development trajectories and obstacles. By comprehensively exploring the diverse applications of targeted mitochondrial nanomaterials, this review aims to catalyze innovative treatment modalities and diagnostic approaches in medical research. STATEMENT OF SIGNIFICANCE: This review presents the latest advancements in mitochondria-targeted nanomaterials for biomedical applications, covering diverse fields such as cancer therapy, bioprobes, imaging, and the treatment of various systemic diseases. The novelty and significance of this work lie in its systematic analysis of the intricate relationship between mitochondria and different diseases, as well as the ingenious design strategies employed to harness the therapeutic potential of nanomaterials. By providing crucial insights into the development of mitochondria-targeted nanomaterials and their applications, this review offers a valuable resource for researchers working on innovative treatment modalities and diagnostic approaches. The scientific impact and interest to the readership lie in the identification of promising avenues for future research and the potential for clinical translation of these cutting-edge technologies.

Oxygen-Evolving Radiotherapy-Radiodynamic Therapy Synergized with NO Gas Therapy by Cerium-Based Rare-Earth Metal-Porphyrin Framework

The efficacy of traditional radiotherapy (RT) has been severely limited by its significant side effects, as well as tumor hypoxia. Here, the nanoscale cerium (Ce)-based metaloxo clusters (Ce(IV)6)-porphyrin (meso-tetra (4-carboxyphenyl) porphyrin, TCPP) framework loaded with L-arginine (LA) (denoted as LA@Ce(IV)6-TCPP) is developed to serve as a multifarious radio enhancer to heighten X-ray absorption and energy transfer accompanied by O2/NO generation for hypoxia-improved RT-radiodynamic therapy (RDT) and gas therapy. Within tumor cells, LA@Ce(IV)6-TCPP will first react with endogenous H2O2 and inducible NO synthase (iNOS) to produce O2 and NO to respectively increase the oxygen supply and reduce oxygen consumption, thus alleviating tumor hypoxia. Then upon X-ray irradiation, LA@Ce(IV)6-TCPP can significantly enhance hydroxyl radical (•OH) generation from Ce(IV)6 metaloxo clusters for RT and synchronously facilitate singlet oxygen (1O2) generation from adjacently-coordinated TCPP for RDT. Moreover, both the •OH and 1O2 can further react with NO to generate more toxic peroxynitrite anions (ONOO-) to inhibit tumor growth for gas therapy. Benefitting from the alleviation of tumor hypoxia and intensified RT-RDT synergized with gas therapy, LA@Ce(IV)6-TCPP elicited superior anticancer outcomes. This work provides an effective RT strategy by using low doses of X-rays to intensify tumor suppression yet reduce systemic toxicity.

Treating Deep-Seated Tumors with Radiodynamic Therapy: Progress and Perspectives

Radiodynamic therapy (RDT), as an emerging cancer treatment method, has attracted attention due to its remarkable therapeutic efficacy using low-dose, high-energy radiation (such as X-rays) and has shown significant potential in cancer treatment. The RDT system typically consists of scintillators and photosensitizers (PSs). Scintillators absorb X-rays and convert them to visible light, activating nearby PSs to generate cytotoxic reactive oxygen species (ROS). Challenges faced by the two-component strategy, including low loading capacity and inefficient energy transfer, hinder its final effectiveness. In addition, the tumor microenvironment (TME) with hypoxia and immunosuppression limits the efficacy of RDTs. Recent advances introduce one-component RDT systems based on nanomaterials with high-Z metal elements, which effectively inhibit deep-seated tumors. These novel RDT systems exhibit immune enhancement and immune memory, potentially eliminating both primary and metastatic tumors. This review comprehensively analyzes recent advances in the rational construction of RDTs, exploring their mechanisms and application in the treatment of deep-seated tumors. Aimed at providing a practical resource for oncology researchers and practitioners, the review offers new perspectives for potential future directions in RDT research.

Effective strategies to enhance the diagnosis and treatment of RCC: The application of biocompatible materials

Renal cell carcinoma (RCC) is recognized as one of the three primary malignant tumors affecting the urinary system, posing a significant risk to human health and life. Despite advancements in understanding RCC, challenges persist in its diagnosis and treatment, particularly in early detection and diagnosis due to issues of low specificity and sensitivity. Consequently, there is an urgent need for the development of effective strategies to enhance diagnostic accuracy and treatment outcomes for RCC. In recent years, with the extensive research on materials for applications in the biomedical field, some materials have been identified as promising for clinical applications, e.g., in the diagnosis and treatment of many tumors, including RCC. Herein, we summarize the latest materials that are being studied and have been applied in the early diagnosis and treatment of RCC. While focusing on their adjuvant effects, we also discuss their technical principles and safety, thus highlighting the value and potential of their application. In addition, we also discuss the limitations of the application of these materials and possible future directions, providing new insights for improving RCC diagnosis and treatment.

SLC25A19 is a novel prognostic biomarker related to immune invasion and ferroptosis in HCC

SLC25A19 is a mitochondrial thiamine pyrophosphate (TPP) carrier that mediates TPP entry into the mitochondria. SLC25A19 has been recognized to play a crucial role in many metabolic diseases, but its role in cancer has not been clearly reported. Based on clinical data from The Cancer Genome Atlas (TCGA), the following parameters were analyzed among HCC patients: SLC25A19 expression, enrichment analyses, immune infiltration, ferroptosis and prognosis analyses. In vitro, the SLC25A19 high expression was validated by qRT-PCR and Immunohistochemistry. Subsequently, a series of cell function experiments, including CCK8, EdU, clone formation, trans-well and scratch assays, were conducted to illustrate the effect of SLC25A19 on the growth and metastasis of cancer cells. Meanwhile, indicators related to ferroptosis were also detected. SCL25A19 is highly expressed in HCC and predicts a poor prognosis. Elevated SLC25A19 expression in HCC patients was markedly associated with T stage, pathological status (PS), tumor status (TS), histologic grade (HG), and AFP. Our results indicate that SLC25A19 has a generally good prognosis predictive and diagnostic ability. The results of gene enrichment analyses showed that SLC25A19 is significantly correlated with immune infiltration, fatty acid metabolism, and ferroptosis marker genes. In vitro experiments have confirmed that silencing SLC25A19 can significantly inhibit the proliferation and migration ability of cancer cells and induce ferroptosis in HCC. In conclusion, these findings indicate that SLC25A19 is novel prognostic biomarker related to immune invasion and ferroptosis in HCC, and it is an excellent candidate for therapeutic target against HCC.

Probing the optical properties and toxicological profile of zinc tungstate nanorods

Zinc tungstate is a semiconductor known for its favorable photocatalytic, photoluminescence, and scintillation properties, coupled with its relatively low cost, reduced toxicity, and high stability in biological and catalytic environments. In particular, zinc tungstate evinces scintillation properties, namely the ability to emit visible light upon absorption of energetic radiation such as x rays, which has led to applications not only as radiation detectors but also for biomedical applications involving the delivery of optical light to deep tissue, such as photodynamic therapy and optogenetics. Here, we report on the synthesis of zinc tungstate nanorods generated via an optimized but facile method, which allows for synthetic control over the aspect ratio of the as-synthesized anisotropic motifs via rational variation of the solution pH. We investigate the effect of aspect ratio on their resulting photoluminescent and radioluminescent properties. We further demonstrate the potential of these zinc tungstate nanorods for biomedical applications, such as photodynamic therapy for cancer treatment, by analyzing their toxicological profile within cell lines and neurons.

A Porphyrin-Based 3D Metal-Organic Framework Featuring [Cu8Cl6]10+ Cluster Secondary Building Units: Synthesis, Structure Elucidation, Anion Exchange, and Peroxidase-Like Activity

Herein, we report a rare example of cationic three-dimensional (3D) metal-organic framework (MOF) of [Cu5Cl3(TMPP)]Cl5 ⋅ xSol (denoted as Cu-TMPP; H2TMPP=meso-tetrakis (6-methylpyridin-3-yl) porphyrin; xSol=encapsulated solvates) supported by [Cu8Cl6]10+ cluster secondary building units (SBUs) wherein the eight faces of the Cl--based octahedron are capped by eight Cu2+. Surface-area analysis indicated that Cu-TMPP features a mesoporous structure and its solvate-like Cl- counterions can be exchanged by BF4 -, PF6 -, and NO3 -. The polyvinylpyrrolidone (PVP) coated Cu-TMPP (denoted as Cu-TMPP-PVP) demonstrated good ROS generating ability, producing ⋅OH in the absence of light (peroxidase-like activity) and 1O2 on light irradiation (650 nm; 25 mW cm-2). This work highlights the potential of Cu-TMPP as a functional carrier of anionic guests such as drugs, for the combination therapy of cancer and other diseases.

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.

Ligand Regulation Strategy to Modulate ROS Nature in a Rhodamine-Iridium(III) Hybrid System for Phototherapy

The efficacy of photodynamic therapy (PDT) is highly dependent on the photosensitizer features. The reactive oxygen species (ROS) generated by photosensitizers is proven to be associated with immunotherapy by triggering immunogenic cell death (ICD) as well. In this work, we establish a rhodamine-iridium(III) hybrid model functioning as a photosensitizer to comprehensively understand its performance and potential applications in photodynamic immunotherapy. Especially, the correlation between the ROS generation efficiency and the energy level of the Ir(III)-based excited state (T1'), modulated by the cyclometalating (C∧N) ligand, is systematically investigated and correlated. We prove that in addition to the direct population of the rhodamine triplet state (T1) formed through the intersystem crossing process with the assistance of a heavy Ir(III) metal center, the fine-tuned T1' state could act as a relay to provide an additional pathway for promoting the cascade energy transfer process that leads to enhanced ROS generation ability. Moreover, type I ROS can be effectively produced by introducing sulfur-containing thiophene units in C∧N ligands, providing a stronger M1 macrophage-activation efficiency under hypoxia to evoke in vivo antitumor immunity. Overall, our work provides a fundamental guideline for the molecular design and exploration of advanced transition-metal-based photosensitizers for biomedical applications.

Hypoxia-activated cascade nanovaccine for synergistic chemoembolization-immune therapy of hepatocellular carcinoma

In this work, a promising treatment strategy for triggering robust antitumor immune responses in transarterial chemoembolization of hepatocellular carcinoma (HCC) is presented. The zeolitic imidazolate framework nanoparticles loaded with hypoxia-activated prodrug tirapazamine and immune adjuvant resiquimod facilitated in situ generation of nanovaccine via a facile approach. The nanovaccine can strengthen the ability of killing the liver cancer cells under hypoxic environment, while was capable of improving immunogenic tumor microenvironment and triggering strong antitumor immune responses by increasing the primary and distant intratumoral infiltration of immune cells such as cytotoxic T cells. Moreover, a porous microcarrier, approved by FDA as pharmaceutical excipient, was designed to achieve safe and effective delivery of the nanovaccine via transarterial therapy in rabbit orthotopic VX2 liver cancer model. The microcarrier exhibited the characteristics of excellent drug loading and occlusion of peripheral artery. The collaborative delivery of the microcarrier and nanovaccine demonstrated an exciting inhibitory effect on solid tumors and tumor metastases, which provided a great potential as novel combination therapy for HCC interventional therapy.

Leveraging Radiation-triggered Metal Prodrug Activation Through Nanosurface Energy Transfer for Directed Radio-chemo-immunotherapy

Metal-based drugs currently dominate the field of chemotherapeutic agents; however, achieving the controlled activation of metal prodrugs remains a substantial challenge. Here, we propose a universal strategy for the radiation-triggered activation of metal prodrugs via nanosurface energy transfer (NSET). The core-shell nanoplatform (Ru-GNC) is composed of gold nanoclusters (GNC) and ruthenium (Ru)-containing organic-inorganic hybrid coatings. Upon X-ray irradiation, chemotherapeutic Ru (II) complexes were released in a controlled manner through a unique NSET process involving the transfer of photoelectron energy from the radiation-excited Ru-GNCs to the Ru-containing hybrid layer. In contrast to the traditional radiation-triggered activation of prodrugs, such an NSET-based system ensures that the reactive species in the tumor microenvironment are present in sufficient quantity and are not easily quenched. Additionally, ultrasmall Ru-GNCs preferably target mitochondria and profoundly disrupt the respiratory chain upon irradiation, leading to radiosensitization by generating abundant reactive oxygen species. Consequently, Ru-GNC-directed radiochemotherapy induces immunogenic cell death, resulting in significant therapeutic outcomes when combined with the programmed cell death-ligand 1 (PD-L1) checkpoint blockade. This NSET strategy represents a breakthrough in designing radiation-triggered nanoplatforms for metal-prodrug-mediated cancer treatment in an efficient and controllable manner.

Nanocatalysts for modulating antitumor immunity: fabrication, mechanisms and applications

Immunotherapy harnesses the inherent immune system in the body to generate systemic antitumor immunity, offering a promising modality for defending against cancer. However, tumor immunosuppression and evasion seriously restrict the immune response rates in clinical settings. Catalytic nanomedicines can transform tumoral substances/metabolites into therapeutic products in situ, offering unique advantages in antitumor immunotherapy. Through catalytic reactions, both tumor eradication and immune regulation can be simultaneously achieved, favoring the development of systemic antitumor immunity. In recent years, with advancements in catalytic chemistry and nanotechnology, catalytic nanomedicines based on nanozymes, photocatalysts, sonocatalysts, Fenton catalysts, electrocatalysts, piezocatalysts, thermocatalysts and radiocatalysts have been rapidly developed with vast applications in cancer immunotherapy. This review provides an introduction to the fabrication of catalytic nanomedicines with an emphasis on their structures and engineering strategies. Furthermore, the catalytic substrates and state-of-the-art applications of nanocatalysts in cancer immunotherapy have also been outlined and discussed. The relationships between nanostructures and immune regulating performance of catalytic nanomedicines are highlighted to provide a deep understanding of their working mechanisms in the tumor microenvironment. Finally, the challenges and development trends are revealed, aiming to provide new insights for the future development of nanocatalysts in catalytic immunotherapy.

Synergistic effect of cold gas plasma and experimental drug exposure exhibits skin cancer toxicity in vitro and in vivo

INTRODUCTION

Skin cancer is often fatal, which motivates new therapy avenues. Recent advances in cancer treatment are indicative of the importance of combination treatments in oncology. Previous studies have identified small molecule-based therapies and redox-based technologies, including photodynamic therapy or medical gas plasma, as promising candidates to target skin cancer.

OBJECTIVE

We aimed to identify effective combinations of experimental small molecules with cold gas plasma for therapy in dermato-oncology.

METHODS

Promising drug candidates were identified after screening an in-house 155-compound library using 3D skin cancer spheroids and high content imaging. Combination effects of selected drugs and cold gas plasma were investigated with respect to oxidative stress, invasion, and viability. Drugs that had combined well with cold gas plasma were further investigated in vascularized tumor organoids in ovo and a xenograft mouse melanoma model in vivo.

RESULTS

The two chromone derivatives Sm837 and IS112 enhanced cold gas plasma-induced oxidative stress, including histone 2A.X phosphorylation, and further reduced proliferation and skin cancer cell viability. Combination treatments of tumor organoids grown in ovo confirmed the principal anti-cancer effect of the selected drugs. While one of the two compounds exerted severe toxicity in vivo, the other (Sm837) resulted in a significant synergistic anti-tumor toxicity at good tolerability. Principal component analysis of protein phosphorylation profiles confirmed profound combination treatment effects in contrast to the monotherapies.

CONCLUSION

We identified a novel compound that, combined with topical cold gas plasma-induced oxidative stress, represents a novel and promising treatment approach to target skin cancer.

Mitochondrial topoisomerase 1 targeted anticancer therapy using irinotecan encapsulated mesoporous MIL-101(Fe) synthesized via a vapour assisted method

Mitochondrial topisomerase 1 (Top1mt) is critical for mtDNA replication, transcription, and energy production. Here, we investigate the carrier-mediated targeted delivery of the anticancer drug irinotecan into the mitochondria to selectively trap Top1mt covalent complexes (Top1mtcc) and its role in anticancer therapeutics. We have designed a biocompatible mesoporous metal-organic framework (MOF) material, namely MIL-101(Fe), as the drug delivery carrier that selectively localizes inside mitochondria. In contrast to the traditional way of synthesising MOFs, here we have employed a vapour-assisted solvothermal method for the synthesis of MIL-101(Fe) using terephthalic acid as the organic linker and Fe(III) as the metal source. The advantage of this method is that it recycles the excess solvent (DMF) and reduces the amount of washing solvent. We demonstrate that MIL-101(Fe)-encapsulated irinotecan (MIL-Iri) was selectively targeted towards the mitochondria to poison Top1mtcc in a dose-dependent manner and was achieved at a low nanomolar drug concentration. We provide evidence that Top1mtcc generated by MIL-Iri leads to mtDNA damage in human colon and breast cancer cells and plays a significant role in cellular toxicity. Altogether, this study provides evidence for a new and effective strategy in anticancer chemotherapy.

The Emerging Landscape for Combating Resistance Associated with Energy-Based Therapies via Nanomedicine

Cancer represents a serious disease with significant implications for public health, imposing substantial economic burden and negative societal consequences. Compared to conventional cancer treatments, such as surgery and chemotherapy, energy-based therapies (ET) based on athermal and thermal ablation provide distinct advantages, including minimally invasive procedures and rapid postoperative recovery. Nevertheless, due to the complex pathophysiology of many solid tumors, the therapeutic effectiveness of ET is often limited. Nanotechnology offers unique opportunities by enabling facile material designs, tunable physicochemical properties, and excellent biocompatibility, thereby further augmenting the outcomes of ET. Numerous nanomaterials have demonstrated the ability to overcome intrinsic therapeutic resistance associated with ET, leading to improved antitumor responses. This comprehensive review systematically summarizes the underlying mechanisms of ET-associated resistance (ETR) and highlights representative applications of nanoplatforms used to mitigate ETR. Overall, this review emphasizes the recent advances in the field and presents a detailed account of novel nanomaterial designs in combating ETR, along with efforts aimed at facilitating their clinical translation.

Intelligent responsive copper-diethyldithiocarbamate-based multifunctional nanomedicine for photothermal-augmented synergistic cancer therapy

The design of multifunctional nanomedicine through the combination of multimodal treatments to achieve the optimal antitumor effect is essential for cancer therapy. Herein, we design and develop a multifunctional theranostic nanoplatform using an iron ion-doxorubicin (DOX) nanoscale coordination polymer (Fe/DOX NCP) as a shell coating on the surface of polyvinyl pyrrolidone (PVP) stabilized copper-diethyldithiocarbamate nanoparticles (Cu(DDC)2 NPs) for combined tumor chemo-/photothermal/chemodynamic therapy. The obtained Cu(DDC)2@Fe/DOX NPs display pH/laser dual-responsive degradation behavior and also exhibit favorable photothermal performance. Under 808 nm laser irradiation, Cu(DDC)2@Fe/DOX NPs can convert light into heat, which not only kills tumor cells via hyperthermia in photothermal therapy (PTT), but also accelerates the degradation of Fe/DOX NCPs to release Fe3+ and DOX. The liberated Fe3+ can be used to catalyze hydrogen peroxide via the Fenton reaction to produce highly toxic hydroxyl radicals (˙OH) in chemodynamic therapy (CDT). The released DOX and the exposed Cu(DDC)2 can cause significant cell death in combined chemotherapy via a superimposed effect. In vitro and in vivo results prove that Cu(DDC)2@Fe/DOX NPs with laser irradiation present remarkable anticancer performances in hyperthermia-enhanced chemo-/CDT. Therefore, this study provides a new strategy for highly efficient synergistic cancer therapy.

Hafnium (Hf)-Chelating Porphyrin-Decorated Gold Nanosensitizers for Enhanced Radio-Radiodynamic Therapy of Colon Carcinoma

X-ray-induced radiodynamic therapy (RDT) that can significantly reduce radiation dose with an improved anticancer effect has emerged as an attractive and promising therapeutic modality for tumors. However, it is highly significant to develop safe and efficient radiosensitizing agents for tumor radiation therapy. Herein, we present a smart nanotheranostic system FA-Au-CH that consists of gold nanoradiosensitizers, photosensitizer chlorin e6 (Ce6), and folic acid (FA) as a folate-receptor-targeting ligand for improved tumor specificity. FA-Au-CH nanoparticles have been demonstrated to be able to simultaneously serve as radiosensitizers and RDT agents for enhanced computed tomography (CT) imaging-guided radiotherapy (RT) of colon carcinoma, owing to the strong X-ray attenuation capability of high-Z elements Au and Hf, as well as the characteristics of Hf that can transfer radiation energy to Ce6 to generate ROS from Ce6 under X-ray irradiation. The integration of RT and RDT in this study demonstrates great efficacy and offers a promising therapeutic modality for the treatment of malignant tumors.

Low-dose pleiotropic radiosensitive nanoformulations for three-pronged radiochemotherapy of hypoxic brain glioblastoma under BOLD/DWI monitoring

Background

Hypoxia-mediated radioresistance is the main obstacle to the successful treatment of glioblastoma (GBM). Enhancing hypoxic radiosensitivity and alleviating tumor hypoxia are both effective means to improve therapeutic efficacy, and the combination of the two is highly desirable and meaningful.

Results

Herein, we construct a low-dose pleiotropic radiosensitive nanoformulation consisting of a high-Z atomic nanocrystal core and mesoporous silica shell, surface-modified with angiopep-2 (ANG) peptide and loaded with nitric oxide (NO) donor and hypoxia-activated prodrug (AQ4N). Benefiting from ANG-mediated transcytosis, this nanoformulation can efficiently cross the BBB and accumulate preferentially in the brain. Low-dose radiation triggers this nanoformulation to exert a three-pronged synergistic therapeutic effect through high-Z-atom-dependent dose deposition enhancement, NO-mediated hypoxia relief, and AQ4N-induced hypoxia-selective killing, thereby significantly inhibiting GBM in situ growth while prolonging survival and maintaining stable body weight in the glioma-bearing mice. Meanwhile, the proposed in vivo 9.4 T BOLD/DWI can realize real-time dynamic assessment of local oxygen supply and radiosensitivity to monitor the therapeutic response of GBM.

Conclusions

This work provides a promising alternative for hypoxia-specific GBM-targeted comprehensive therapy, noninvasive monitoring, and precise prognosis.

Graphical Abstract

Advances of hafnium based nanomaterials for cancer theranostics

Hafnium-based nanomaterials (Hf-NMs) have attracted the interest of numerous biomedical researchers by their unique properties. Recent years have witnessed significant advancements in the field of Hafnium-based nanomaterials, particularly in the context of cancer diagnosis and treatment. However, research in this area, especially concerning the clinical application of Hafnium-based nanomaterials, has not been thoroughly reviewed. This review will cover: 1) Classification and synthesis of Hafnium-based nanomaterials including Hafnium oxide nanomaterials, Hafnium Metal-Organic Frameworks/nanoscale coordination polymers (MOFs/NCPs); 2) Hafnium-based nanomaterials act as contrast enhancement agent for cancer imaging, and hafnium-based nanomaterials used for diagnosis in cancer liquid biopsy; 3) hafnium-based nanomaterials for cancer therapy, including hafnium-based nanomaterials for radiotherapy, hafnium-based nanomaterials for photodynamic therapy, hafnium-based nanomaterials for various combined therapy; and 4) Translation, toxicity, and safety for Hf-NMs in human and preclinical animal models. More attention will be given to the clinical translation of Hf-NMs in cancer.

Nanomedicine Strategies in Conquering and Utilizing the Cancer Hypoxia Environment

Cancer with a complex pathological process is a major disease to human welfare. Due to the imbalance between oxygen (O2) supply and consumption, hypoxia is a natural characteristic of most solid tumors and an important obstacle for cancer therapy, which is closely related to tumor proliferation, metastasis, and invasion. Various strategies to exploit the feature of tumor hypoxia have been developed in the past decade, which can be used to alleviate tumor hypoxia, or utilize the hypoxia for targeted delivery and diagnostic imaging. The strategies to alleviate tumor hypoxia include delivering O2, in situ O2 generation, reprogramming the tumor vascular system, decreasing O2 consumption, and inhibiting HIF-1 related pathways. On the other side, hypoxia can also be utilized for hypoxia-responsive chemical construction and hypoxia-active prodrug-based strategies. Taking advantage of hypoxia in the tumor region, a number of methods have been applied to identify and keep track of changes in tumor hypoxia. Herein, we thoroughly review the recent progress of nanomedicine strategies in both conquering and utilizing hypoxia to combat cancer and put forward the prospect of emerging nanomaterials for future clinical transformation, which hopes to provide perspectives in nanomaterials design.

Prospects of nanoparticle-based radioenhancement for radiotherapy

Radiotherapy is a key pillar of solid cancer treatment. Despite a high level of conformal dose deposition, radiotherapy is limited due to co-irradiation of organs at risk and subsequent normal tissue toxicities. Nanotechnology offers an attractive opportunity for increasing the efficacy and safety of cancer radiotherapy. Leveraging the freedom of design and the growing synthetic capabilities of the nanomaterial-community, a variety of engineered nanomaterials have been designed and investigated as radiosensitizers or radioenhancers. While research so far has been primarily focused on gold nanoparticles and other high atomic number materials to increase the absorption cross section of tumor tissue, recent studies are challenging the traditional concept of high-Z nanoparticle radioenhancers and highlight the importance of catalytic activity. This review provides a concise overview on the knowledge of nanoparticle radioenhancement mechanisms and their quantification. It critically discusses potential radioenhancer candidate materials and general design criteria for different radiation therapy modalities, and concludes with research priorities in order to advance the development of nanomaterials, to enhance the efficacy of radiotherapy and to increase at the same time the therapeutic window.

Functional Materials for Subcellular Targeting Strategies in Cancer Therapy: Progress and Prospects

Neoadjuvant and adjuvant therapies have made significant progress in cancer treatment. However, tumor adjuvant therapy still faces challenges due to the intrinsic heterogeneity of cancer, genomic instability, and the formation of an immunosuppressive tumor microenvironment. Functional materials possess unique biological properties such as long circulation times, tumor-specific targeting, and immunomodulation. The combination of functional materials with natural substances and nanotechnology has led to the development of smart biomaterials with multiple functions, high biocompatibilities, and negligible immunogenicities, which can be used for precise cancer treatment. Recently, subcellular structure-targeting functional materials have received particular attention in various biomedical applications including the diagnosis, sensing, and imaging of tumors and drug delivery. Subcellular organelle-targeting materials can precisely accumulate therapeutic agents in organelles, considerably reduce the threshold dosages of therapeutic agents, and minimize drug-related side effects. This review provides a systematic and comprehensive overview of the research progress in subcellular organelle-targeted cancer therapy based on functional nanomaterials. Moreover, it explains the challenges and prospects of subcellular organelle-targeting functional materials in precision oncology. The review will serve as an excellent cutting-edge guide for researchers in the field of subcellular organelle-targeted cancer therapy.

Pure Organic AIE Nanoscintillator for X-ray Mediated Type I and Type II Photodynamic Therapy

X-ray induced photodynamic therapy (X-PDT) circumvents the poor penetration depth of conventional PDT with minimal radio-resistance generation. However, conventional X-PDT typically requires inorganic scintillators as energy transducers to excite neighboring photosensitizers (PSs) to generate reactive oxygen species (ROS). Herein, a pure organic aggregation-induced emission (AIE) nanoscintillator (TBDCR NPs) that can massively generate both type I and type II ROS under direct X-ray irradiation is reported for hypoxia-tolerant X-PDT. Heteroatoms are introduced to enhance X-ray harvesting and ROS generation ability, and AIE-active TBDCR exhibits aggregation-enhanced ROS especially less oxygen-dependent hydroxyl radical (HO•- , type I) generation ability. TBDCR NPs with a distinctive PEG crystalline shell to provide a rigid intraparticle microenvironment show further enhanced ROS generation. Intriguingly, TBDCR NPs show bright near-infrared fluorescence and massive singlet oxygen and HO•- generation under direct X-ray irradiation, which demonstrate excellent antitumor X-PDT performance both in vitro and in vivo. To the best of knowledge, this is the first pure organic PS capable of generating both 1 O2 and radicals (HO•- ) in response to direct X-ray irradiation, which shall provide new insights for designing organic scintillators with excellent X-ray harvesting and predominant free radical generation for efficient X-PDT.

Selective CO2 reduction to CH3OH over atomic dual-metal sites embedded in a metal-organic framework with high-energy radiation

The efficient use of renewable X/γ-rays or accelerated electrons for chemical transformation of CO2 and water to fuels holds promise for a carbon-neutral economy; however, such processes are challenging to implement and require the assistance of catalysts capable of sensitizing secondary electron scattering and providing active metal sites to bind intermediates. Here we show atomic Cu-Ni dual-metal sites embedded in a metal-organic framework enable efficient and selective CH3OH production (~98%) over multiple irradiated cycles. The usage of practical electron-beam irradiation (200 keV; 40 kGy min-1) with a cost-effective hydroxyl radical scavenger promotes CH3OH production rate to 0.27 mmol g-1 min-1. Moreover, time-resolved experiments with calculations reveal the direct generation of CO2•‒ radical anions via aqueous electrons attachment occurred on nanosecond timescale, and cascade hydrogenation steps. Our study highlights a radiolytic route to produce CH3OH with CO2 feedstock and introduces a desirable atomic structure to improve performance.

Harnessing Hafnium-Based Nanomaterials for Cancer Diagnosis and Therapy

With the rapid development of nanotechnology and nanomedicine, there are great interests in employing nanomaterials to improve the efficiency of disease diagnosis and treatment. The clinical translation of hafnium oxide (HfO2 ), commercially namedas NBTXR3, as a new kind of nanoradiosensitizer for radiotherapy (RT) of cancers has aroused extensive interest in researches on Hf-based nanomaterials for biomedical application. In the past 20 years, Hf-based nanomaterials have emerged as potential and important nanomedicine for computed tomography (CT)-involved bioimaging and RT-associated cancer treatment due to their excellent electronic structures and intrinsic physiochemical properties. In this review, a bibliometric analysis method is employed to summarize the progress on the synthesis technology of various Hf-based nanomaterials, including HfO2 , HfO2 -based compounds, and Hf-organic ligand coordination hybrids, such as metal-organic frameworks or nanoscaled coordination polymers. Moreover, current states in the application of Hf-based CT-involved contrasts for tissue imaging or cancer diagnosis are reviewed in detail. Importantly, the recent advances in Hf-based nanomaterials-mediated radiosensitization and synergistic RT with other current mainstream treatments are also generalized. Finally, current challenges and future perspectives of Hf-based nanomaterials with a view to maximize their great potential in the research of translational medicine are also discussed.

Cu-doped polypyrrole hydrogel with tumor catalyst activity for NIR-II thermo-radiotherapy

Introduction: Radiotherapy (RT) is one of the key methods for treating breast cancer. However, the effect of single RT is often poor because of insufficient deposition of X-rays in tumor sites and radiation resistance induced by the abnormal tumor microenvironment (overexpression of glutathione (GSH)). The development of multifunctional RT sensitizers and synergetic therapeutic strategies is, therefore, a promising area for enhancing the anticancer effect of RT. Methods: In this study, a multifunctional nanozyme hydrogel based on Cu-doped polypyrrole (CuP) was designed to work concertedly with a second near-infrared thermal RT. The CuP-based hydrogel (CH) reached the tumor site when injected in-situ and achieved long-term storage. Results: Once stimulated with 1064-nm laser irradiation, the heated and softened hydrogel system released CuP nanozyme to provide photothermal therapy, thereby inhibiting the repair of DNA damage caused by RT. In addition, CuP with dual nanozyme activity depleted the intracellular GSH to reduce the antioxidant capacity of the tumor. Moreover, CuP converted H₂O₂ to produce ·OH to directly kill the tumor cells, thus enhancing the capability of low-dose RT to inhibit tumor growth. In vivo experiments showed that the CH system used in combination with a low-power 1064-nm laser and low-dose RT (4 Gy) exhibited good synergistic anticancer effects and biological safety. Discussion: As a new light-responsive hydrogel system, CH holds immense potential for radio-sensitization.

Metal-organic coordination polymers for delivery of immunomodulatory agents, and infectious disease and cancer vaccines

Metal-organic coordination polymers (CPs) are a broad class of materials that include metal-organic frameworks (MOFs). CPs are highly ordered crystalline materials that are composed of metal ions (or metal ion clusters) and multidentate organic ligands that serve as linkers. One-, two-, and three-dimensional CPs can be formed, with 2D and 3D structures referred to as MOFs. CPs have gained a lot of attention due to attractive structural features like structure versatility and tunability, and well-defined pores that enable the encapsulation of cargo. Further, CPs show a lot of promise for drug delivery applications, but only a very limited number of CPs are currently being evaluated in clinical trials. In this review, we outlined features that are desired for CP-based drug delivery platform, and briefly described most relevant characterization techniques. We highlighted some of the recent efforts directed toward developing CP-based drug delivery platforms with the emphasis on vaccines against cancer, infectious diseases, and viruses. We hope this review will be a helpful guide for those interested in the design and evaluation of CP-based immunological drug delivery platforms. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Regulating electron transportation by tungsten oxide nanocapacitors for enhanced radiation therapy

In the process of radiation therapy (RT), the cytotoxic effects of excited electrons generated from water radiolysis tend to be underestimated due to multiple biochemical factors, particularly the recombination between electrons and hydroxyl radicals (·OH). To take better advantage of radiolytic electrons, we constructed WO₃ nanocapacitors that reversibly charge and discharge electrons to regulate electron transportation and utilization. During radiolysis, WO₃ nanocapacitors could contain the generated electrons that block electron-·OH recombination and contribute to the yield of ·OH at a high level. These contained electrons could be discharged from WO₃ nanocapacitors after radiolysis, resulting in the consumption of cytosolic NAD⁺ and impairment of NAD⁺-dependent DNA repair. Overall, this strategy of nanocapacitor-based radiosensitization improves the radiotherapeutic effects by increasing the utilization of radiolytic electrons and ·OH, warranting further validation in multiple tumour models and preclinical experiments.