NaCeF4:Gd,Tb Scintillator as an X-ray Responsive Photosensitizer for Multimodal Imaging-Guided Synchronous Radio/Radiodynamic Therapy

A Lanthanide Nanoparticle-Aggregation-Induced Emission Photosensitizer Complex System Drives Coupled Triplet Energy Transfer for Enhanced Radio-Photodynamic Therapy

Cerenkov light (CL), utilized as an internal excitation source for photodynamic therapy (PDT), addresses the limitations of laser penetration and has substantial potential for seamlessly integrating clinical radiotheranostics with phototheranostics. Nevertheless, the effectiveness of CL-mediated PDT is significantly hindered by challenges, such as the low intensity of CL and inadequate energy transfer between the CL donor and photosensitizers (PSs). In this study, a novel approach is introduced for enhanced radionuclide-activated radio-photodynamic therapy utilizing a hybrid nanoparticle system composed of lanthanide nanoparticles and an aggregation-induced emission photosensitizer (AIE PS), designated LnNP-TQ NPs. This system enables lanthanide nanoparticles to optimize the decay energy of radionuclides, effectively sensitizing the AIE PS through triplet energy transfer (TET)-mediated processes with an efficiency approaching 100%. When activated by the clinical radionuclide 18F for positron emission tomography imaging, the LnNP-TQ NPs substantially inhibited tumor growth via effective singlet oxygen (1O2) generation. This strategy, which optimally harnesses radionuclide energy and achieves efficient energy transfer, offers a promising pathway for enhancing radiotherapy-phototherapy efficacy in 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.

Sustained Drug Release from Dual-Responsive Hydrogels for Local Cancer Chemo-Photothermal Therapy

As an exceptional carrier for localized drug delivery to tumors, hydrogels can achieve prolonged drug release through careful design and adjustments, effectively targeting cancer cells and minimizing side effects. This study investigates a novel dual-responsive hydrogel system designed for the delivery of nanomedicines, focusing on drug release and the local antitumor efficacy of SN-38-cholesterol nanoparticles (SN-38-chol NPs) and polydopamine NPs (PDA NPs)/poly(n-isopropylacrylamide) (pNIPAM) hydrogels. By combining the thermosensitive properties of pNIPAM with the near-infrared (NIR) responsiveness of PDA NPs, the hydrogel aims to enhance on-demand drug release. SN-38-chol NPs, known for their stability and small size, are incorporated into the hydrogel to improve drug release dynamics. The investigation reveals a drug release cycle of over three weeks, maintaining sensitivity to both temperature and NIR light for controlled drug release. In vivo studies demonstrate the high tumor growth inhibition performance of the system after photothermal treatment induced by 808 nm NIR light. These results suggest that the drug-carrying hydrogel system holds promise for diverse applications in chemical and physical therapies, including the treatment of malignant wounds, post-surgery wound healing, and direct tumor treatment. This study establishes the potential of SN-38-chol NPs and PDA NPs/pNIPAM hydrogels as effective platforms for chemo-phototherapy.

Advances in nanoparticle-based radiotherapy for cancer treatment

Radiotherapy has long been recognized as an effective conventional approach in both clinical and scientific research, primarily through mechanisms involving DNA destruction or the generation of reactive oxygen species to target tumors. However, significant challenges persist, including the unavoidable damage to normal tissues and the development of radiation resistance. As a result, nanotechnology-based radiotherapy has garnered considerable attention for its potential to enhance precision in irradiation, improve radiosensitization, and achieve therapeutic advancements. Importantly, radiotherapy alone frequently falls short of fully eradicating tumors. Consequently, to augment the efficacy of radiotherapy, it is often integrated with other therapeutic strategies. This review elucidates the mechanisms of radiotherapy sensitization based on diverse nanoparticles. Typically, radiotherapy is sensitized through augmenting reactive oxygen species production, targeted radiotherapy, hypoxia relief, enhancement of antitumor immune microenvironment, and G2/M cell cycle arrest. Moreover, the incorporation of nanoparticle-based anti-tumor strategies with radiotherapy markedly enhances the current state of radiotherapy. Additionally, a compilation of clinical trials utilizing nano-radioenhancers is presented. Finally, future prospects for clinical translation in this field are thoroughly examined.

A new era of cancer phototherapy: mechanisms and applications

The past decades have witnessed great strides in phototherapy as an experimental option or regulation-approved treatment in numerous cancer indications. Of particular interest is nanoscale photosensitizer-based phototherapy, which has been established as a prominent candidate for advanced tumor treatment by virtue of its high efficacy and safety. Despite considerable research progress on materials, methods and devices in nanoscale photosensitizing agent-based phototherapy, their mechanisms of action are not always clear, which impedes their practical application in cancer treatment. Hence, from a new perspective, this review elaborates the working mechanisms, involving impairment and moderation effects, of diverse phototherapies on cells, organelles, organs, and tissues. Furthermore, the most current available phototherapy modalities are categorized as photodynamic, photothermal, photo-immune, photo-gas, and radio therapies in this review. A comprehensive understanding of the inferiority and superiority of various phototherapies will facilitate the advent of a new era of cancer phototherapy.

Water-Vapor-Triggered Dual-Mode Optical Responses in Rare-Earth-Doped Hollow Nanospheres

Multimode responsive optical materials are garnering ever-increasing attention due to their diverse applications. This work showcases a film assembled with rare-earth-doped CaF2 hollow nanospheres that exhibit water-vapor-triggered dual-mode optical responses. Upon exposure to flowing water vapor, the film rapidly (less than 1.5 s for a 7.7 μm thickness) transitions to a transparent state and simultaneously undergoes a sharp decrease in the photoluminescence intensity. Both of these changes fully reverse upon water evaporation, demonstrating an impressive reversibility over at least 200 cycles. The water-vapor-induced dual-mode responses are attributed to the altered incident light propagation path stemming from the similar refractive indices between CaF2 and water, coupled with the water-induced energy loss of the rare-earth ions. The fabrication of encryption patterns displaying separate signals in multiple channels, as well as the demonstration of noncontact sensing for water vapor distribution, underscore the promising application potential of this dual-mode responsive system.

Nanoscale Mixed-Ligand Metal-Organic Framework for X-ray Stimulated Cancer Therapy

Concurrent localized radiotherapy and systemic chemotherapy are standards of care for many cancers, but these treatment regimens cause severe adverse effects in many patients. Herein, we report the design of a mixed-ligand nanoscale metal-organic framework (nMOF) with the ability to simultaneously enhance radiotherapeutic effects and trigger the release of a potent chemotherapeutic under X-ray irradiation. We synthesized a new functional quaterphenyl dicarboxylate ligand conjugated with SN38 (H2QP-SN) via a hydroxyl radical-responsive covalent linkage. Because of the similar length of QP-SN and bis(p-benzoato)porphyrin (DBP) ligands, QP-SN was incorporated into Hf-DBP nMOF to afford a novel multifunctional mixed-ligand Hf-DBP-QP-SN nMOF with good biocompatibility. Hf-DBP-QP-SN not only enhances radiation damage to tumors via a unique radiotherapy-radiodynamic therapy (RT-RDT) process but also increases ·OH generation from radiolysis with electron-dense Hf12 secondary building units (SBUs) to release SN38 from Hf-DBP-QP-SN for chemotherapy. Elevated levels of hydrogen peroxide in the tumor microenvironment further stimulate the release of SN38 by enhancing ·OH generation under X-ray irradiation. With low doses of X-ray irradiation, Hf-DBP-QP-SN suppressed the growth of CT26 colon and 4T1 breast tumors by 93.5% and 95.2%, respectively, without any sign of general toxicity. Our study highlights the potential of using ionizing radiation-mediated chemistry for on-demand activation of nanotherapeutics for synergistic radiotherapy and chemotherapy without causing severe adverse effects.

Nature-Inspired Artificial Aggregation-Induced Emission Antenna for Assembling with Algae to Promote Photosynthesis

Inspired by the structure of chlorophyll assembled on the thylakoid membrane through its long hydrophobic chain, we designed cationic aggregation-induced emission (AIE) amphiphiles with two long hydrophobic chains to assemble with the electronegative cytomembrane of algae for efficiently converting natural ultraviolet light into usable blue light to promote photosynthesis. The photosynthesis efficiency of algae depended on the carbon chain length of the AIE amphiphile due to the difference in assembly capacity with the algal membrane. The AIE amphiphile with two hydrophobic chains of 12 carbon atoms effectively intercalated into the cytomembrane of algae, serving as an artificial membrane-embedded antenna to significantly improve light utilization by algae. This resulted in increased electron generation and a 98.6% increase in the electron transfer rate. Consequently, oxygen and ATP production in light-dependent reactions were boosted by about 100% and 64.5%, respectively, and the lipid yield increased by 45.7% in dark reactions. In addition, the AIE amphiphile also demonstrated a low biotoxicity. These results highlight the potential of AIE amphiphiles as membrane-embedded artificial antennas for optimizing natural photosynthesis.

Polypyrrole/iron-glycol chitosan nanozymes mediate M1 macrophages to enhance the X-ray-triggered photodynamic therapy for bladder cancer by promoting antitumor immunity

X-ray Photodynamic Therapy (XPDT) is an emerging, deeply penetrating, and non-invasive tumor treatment that stimulates robust antitumor immune responses. However, its efficacy is often limited by low therapeutic delivery and immunosuppressant within the tumor microenvironment. This challenge can potentially be addressed by utilizing X-ray responsive iron-glycol chitosan-polypyrrole nanozymes (GCS-I-PPy NZs), which activate M1 macrophages. These nanozymes increase tumor infiltration and enhance the macrophages' intrinsic immune response and their ability to stimulate adaptive immunity. Authors have designed biocompatible, photosensitizer-containing GCS-I-PPy NZs using oxidation/reduction reactions. These nanozymes were internalized by M1 macrophages to form RAW-GCS-I-PPy NZs. Authors' results demonstrated that these engineered macrophages effectively delivered the nanozymes with potentially high tumor accumulation. Within the tumor microenvironment, the accumulated GCS-I-PPy NZs underwent X-ray irradiation, generating reactive oxygen species (ROS). This ROS augmentation significantly enhanced the therapeutic effect of XPDT and synergistically promoted T cell infiltration into the tumor. These findings suggest that nano-engineered M1 macrophages can effectively boost the immune effects of XPDT, providing a promising strategy for enhancing cancer immunotherapy. The ability of GCS-I-PPy NZs to mediate M1 macrophage activation and increase tumor infiltration highlights their potential in overcoming the limitations of current XPDT approaches and improving therapeutic outcomes in melanoma and other cancers.

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.

Full-course NIR-II imaging-navigated fractionated photodynamic therapy of bladder tumours with X-ray-activated nanotransducers

The poor 5-year survival rate for bladder cancers is associated with the lack of efficient diagnostic and treatment techniques. Despite cystoscopy-assisted photomedicine and external radiation being promising modalities to supplement or replace surgery, they remain invasive or fail to provide real-time navigation. Here, we report non-invasive fractionated photodynamic therapy of bladder cancer with full-course real-time near-infrared-II imaging based on engineered X-ray-activated nanotransducers that contain lanthanide-doped nanoscintillators with concurrent emissions in visible and the second near-infrared regions and conjugated photosensitizers. Following intravesical instillation in mice with carcinogen-induced autochthonous bladder tumours, tumour-homing peptide-labelled nanotransducers realize enhanced tumour regression, robust recurrence inhibition, improved survival rates, and restored immune homeostasis under X-ray irradiation with accompanied near-infrared-II imaging. On-demand fractionated photodynamic therapy with customized doses is further achieved based on quantifiable near-infrared-II imaging signal-to-background ratios. Our study presents a promising non-invasive strategy to confront the current bladder cancer dilemma from diagnosis to treatment and prognosis.

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.

Current advance of nanotechnology in diagnosis and treatment for malignant tumors

Cancer remains a significant risk to human health. Nanomedicine is a new multidisciplinary field that is garnering a lot of interest and investigation. Nanomedicine shows great potential for cancer diagnosis and treatment. Specifically engineered nanoparticles can be employed as contrast agents in cancer diagnostics to enable high sensitivity and high-resolution tumor detection by imaging examinations. Novel approaches for tumor labeling and detection are also made possible by the use of nanoprobes and nanobiosensors. The achievement of targeted medication delivery in cancer therapy can be accomplished through the rational design and manufacture of nanodrug carriers. Nanoparticles have the capability to effectively transport medications or gene fragments to tumor tissues via passive or active targeting processes, thus enhancing treatment outcomes while minimizing harm to healthy tissues. Simultaneously, nanoparticles can be employed in the context of radiation sensitization and photothermal therapy to enhance the therapeutic efficacy of malignant tumors. This review presents a literature overview and summary of how nanotechnology is used in the diagnosis and treatment of malignant tumors. According to oncological diseases originating from different systems of the body and combining the pathophysiological features of cancers at different sites, we review the most recent developments in nanotechnology applications. Finally, we briefly discuss the prospects and challenges of nanotechnology in cancer.

Russell Mechanism-Mediated Cancer Therapy: A Minireview

The Russell mechanism, proposed by Russell, is a cyclic mechanism for the formation of linear tetroxide intermediates, which can spontaneously produce cytotoxic singlet oxygen (1O2) independent of oxygen, suggesting its anticancer potential. Compared with other mainstream anticancer strategies, the Russell mechanism employed for killing cancer cells does not require external energy input, harsh pH condition, and sufficient oxygen. However, up till now, the applications of Russell mechanism in antitumor therapy have been relatively rare, and there is almost no summary of the Russell mechanism in the cancer therapy field. This minireview introduces the different metal elements-based Russell mechanisms and the relevant research progress in Russell mechanism-based cancer therapy in recent years. At the same time, we briefly discussed the current challenges and future development regarding the applications of Russell mechanism. It is hoped that this review can further expand the research of Russell Mechanism in the biomedical field, and inspire researchers to extend its application fields to antibacterial, antiinflammatory, and wound healing uses.

Boosting the sonodynamic performance of CoBiMn-layered double hydroxide nanoparticles via tumor microenvironment regulation for ultrasound imaging-guided sonodynamic therapy

Sonodynamic therapy (SDT), a promising strategy for cancer treatment with the ability for deep tissue penetration, has received widespread attention in recent years. Sonosensitizers with intrinsic characteristics for tumor-specific curative effects, tumor microenvironment (TME) regulation and tumor diagnosis are in high demand. Herein, amorphous CoBiMn-layered double hydroxide (a-CoBiMn-LDH) nanoparticles are presented as multifunctional sonosensitizers to trigger reactive oxygen species (ROS) generation for ultrasound (US) imaging-guided SDT. Hydrothermal-synthesized CoBiMn-LDH nanoparticles are etched via a simple acid treatment to obtain a-CoBiMn-LDH nanoparticles with abundant defects. The a-CoBiMn-LDH nanoparticles give greater ROS generation upon US irradiation, reaching levels ~ 3.3 times and ~ 8.2 times those of the crystalline CoBiMn-LDH nanoparticles and commercial TiO2 sonosensitizer, respectively. This excellent US-triggered ROS generation performance can be attributed to the defect-induced narrow band gap and promoted electrons and holes (e-/h+) separation. More importantly, the presence of Mn4+ enables the a-CoBiMn-LDH nanoparticles to regulate the TME by decomposing H2O2 into O2 for hypoxia relief and US imaging, and consuming glutathione (GSH) for protection against ROS clearance. Biological mechanism analysis shows that a-CoBiMn-LDH nanoparticles modified with polyethylene glycol can serve as a multifunctional sonosensitizer to effectively kill cancer cells in vitro and eliminate tumors in vivo under US irradiation by activating p53, apoptosis, and oxidative phosphorylation-related signaling pathways.

Recent Advances in Photosensitizer Materials for Light-Mediated Tumor Therapy

Photodynamic therapy (PDT) as an emerging therapeutic method has drawn much attention in the treatment field for cancer. Photosensitizer, which can convert photon energy into cytotoxic species under light irradiation, is the core component in PDT. The design of photosensitizers still faces problems of light absorption, targeting, penetration and oxygen dependence. With the rapid progress of material science, various photosensitizers have been developed to produce cytotoxic species for treatment of tumor with high selectivity, safety, and noninvasiveness. Besides, the applications of photosensitizers have been expanded to diverse cancer treatments such as drug release, optogenetics and immune checkpoint blockade. In this review, we summarize the recent advances of photosensitizers in various therapeutic methods for cancer. Prevailing challenges and further prospects associated with photosensitizers are also discussed.

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.

Application and progress of nanozymes in antitumor therapy

Tumors remain one of the major threats to public health and there is an urgent need to design new pharmaceutical agents for their diagnosis and treatment. In recent years, due to the rapid development of nanotechnology, biotechnology, catalytic science, and theoretical computing, subtlety has gradually made great progress in research related to tumor diagnosis and treatment. Compared to conventional drugs, enzymes can improve drug distribution and enhance drug enrichment at the tumor site, thereby reducing drug side effects and enhancing drug efficacy. Nanozymes can also be used as tumor tracking imaging agents to reshape the tumor microenvironment, providing a versatile platform for the diagnosis and treatment of malignancies. In this paper, we review the current status of research on enzymes in oncology and analyze novel oncology therapeutic approaches and related mechanisms. To date, a large number of nanomaterials, such as noble metal nanomaterials, nonmetallic nanomaterials, and carbon-based nanomaterials, have been shown to be able to function like natural enzymes, particularly with significant advantages in tumor therapy. In light of this, the authors in this review have systematically summarized and evaluated the construction, enzymatic activity, and their characteristics of nanozymes with respect to current modalities of tumor treatment. In addition, the application and research progress of different types of nicknames and their features in recent years are summarized in detail. We conclude with a summary and outlook on the study of nanozymes in tumor diagnosis and treatment. It is hoped that this review will inspire researchers in the fields of nanotechnology, chemistry, biology, materials science and theoretical computing, and contribute to the development of nano-enzymology.

Nanomaterials-Induced Redox Imbalance: Challenged and Opportunities for Nanomaterials in Cancer Therapy

Cancer cells typically display redox imbalance compared with normal cells due to increased metabolic rate, accumulated mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This redox imbalance may regulate gene expression, alter protein stability, and modulate existing cellular programs, resulting in inefficient treatment modalities. Therapeutic strategies targeting intra- or extracellular redox states of cancer cells at varying state of progression may trigger programmed cell death if exceeded a certain threshold, enabling therapeutic selectivity and overcoming cancer resistance to radiotherapy and chemotherapy. Nanotechnology provides new opportunities for modulating redox state in cancer cells due to their excellent designability and high reactivity. Various nanomaterials are widely researched to enhance highly reactive substances (free radicals) production, disrupt the endogenous antioxidant defense systems, or both. Here, the physiological features of redox imbalance in cancer cells are described and the challenges in modulating redox state in cancer cells are illustrated. Then, nanomaterials that regulate redox imbalance are classified and elaborated upon based on their ability to target redox regulations. Finally, the future perspectives in this field are proposed. It is hoped this review provides guidance for the design of nanomaterials-based approaches involving modulating intra- or extracellular redox states for cancer therapy, especially for cancers resistant to radiotherapy or chemotherapy, etc.

Radiation responsive PROTAC nanoparticles for tumor-specific proteolysis enhanced radiotherapy

Proteolysis targeting chimeras (PROTACs) is a promising strategy for cancer therapy. However, the always-on bioactivity of PROTACs may lead to non-target toxicity, which restricts their antitumor performance. Here, we developed an X-ray radiation responsive PROTAC nanomicelle (RCNprotac) by covalently conjugating a reported small molecule PROTAC (MZ1) to hydrophilic PEG via a diselenide bond-containing carbon chain, which then self-assembled into a 141.80 ± 5.66 nm nanomicelle. The RCNprotac displayed no bioactivity during circulation due to the occupation of the hydroxyl group on the E3 ubiquitin ligand component and could effectively accumulate at the tumor site owing to the enhanced permeability and retention effect. Upon exposure to X-ray radiation, the radiation-sensitive diselenide bonds were broken to specifically release MZ1 for tumor BRD4 protein degradation. Furthermore, the reduction in the BRD4 protein level could increase the tumor's sensitivity to radiation. RCNprotac showed a synergistic enhancement of antitumor effects both in vitro and in vivo. We believe that this X-ray-responsive PROTAC nanomicelle could provide a new strategy for the X-ray-activated spatiotemporally controlled protein degradation and for the BRD4 proteolysis enhanced tumor radiosensitivity.

Nanomaterials for light-mediated therapeutics in deep tissue

Light-mediated therapeutics, including photodynamic therapy, photothermal therapy and light-triggered drug delivery, have been widely studied due to their high specificity and effective therapy. However, conventional light-mediated therapies usually depend on the activation of light-sensitive molecules with UV or visible light, which have poor penetration in biological tissues. Over the past decade, efforts have been made to engineer nanosystems that can generate luminescence through excitation with near-infrared (NIR) light, ultrasound or X-ray. Certain nanosystems can even carry out light-mediated therapy through chemiluminescence, eliminating the need for external activation. Compared to UV or visible light, these 4 excitation modes penetrate more deeply into biological tissues, triggering light-mediated therapy in deeper tissues. In this review, we systematically report the design and mechanisms of different luminescent nanosystems excited by the 4 excitation sources, methods to enhance the generated luminescence, and recent applications of such nanosystems in deep tissue light-mediated therapeutics.

Gene and Photothermal Combination Therapy: Principle, Materials, and Amplified Anticancer Intervention

Gene therapy (GT) and photothermal therapy (PTT) have emerged as promising alternatives to chemotherapy and radiotherapy for cancer treatment, offering noninvasiveness and reduced side effects. However, their efficacy as standalone treatments is limited. GT exhibits slow response rates, while PTT is confined to local tumor ablation. The convergence of GT and PTT, known as GT-PTT, facilitated by photothermal gene nanocarriers, has attracted considerable attention across various disciplines. In this integrated approach, GT reciprocates PTT by sensitizing cellular response to heat, while PTT benefits GT by improving gene translocation, unpacking, and expression. Consequently, this integration presents a unique opportunity for cancer therapy with rapid response and improved effectiveness. Extensive efforts over the past few years have been dedicated to the development of GT-PTT, resulting in notable achievements and rapid progress from the laboratory to potential clinical applications. This comprehensive review outlines recent advances in GT-PTT, including synergistic mechanisms, material systems, imaging-guided therapy, and anticancer applications. It also explores the challenges and future prospects in this nascent field. By presenting innovative ideas and insights into the implementation of GT-PTT for enhanced cancer therapy, this review aims to inspire further progress in this promising area of research.

Renal clearable magnetic nanoparticles for magnetic resonance imaging and guided therapy

Magnetic resonance imaging (MRI) is a non-invasive, radiation-free imaging technique widely used for disease detection and therapeutic evaluation due to its infinite penetration depth. Magnetic nanoparticles (MNPs) have unique magnetic and physicochemical properties, making them ideal as contrast agents for MRI. However, the in vivo toxicity of MNPs, resulting from metal ion leakage and long-term accumulation in the reticuloendothelial system (RES), limits their clinical application. To overcome these challenges, there is considerable interest in the development of renal-clearable MNPs that can be completely cleared through the kidney, reducing retention time and potential toxic risks. In this review, we provide an overview of recent advancements in the development of renal-clearable MNPs for disease imaging and treatment. We discuss the factors influencing renal clearance, summarize the types of renal-clearable MNPs, their synthesis methods, and biomedical applications. This review aims to offer comprehensive information for the design and clinical translation of renal-clearable MNPs. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Biosensing.

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.

Optimized strategies of ROS-based nanodynamic therapies for tumor theranostics

Reactive oxygen species (ROS) play a crucial role in regulating the metabolism of tumor growth, metastasis, death and other biological processes. ROS-based nanodynamic therapies (NDTs) are becoming attractive due to non-invasive, low side effects and tumor-specific advantages. NDTs have rapidly developed into numerous branches, such as photodynamic therapy, chemodynamic therapy, sonodynamic therapy and so on. However, the complexity of the tumor microenvironment and the limitations of existing sensitizers have greatly restricted the therapeutic effects of NDTs, which heavily rely on ROS levels. To address the limitations of NDTs, various strategies have been developed to increase ROS yield, which is an urgent aspect for the positive development of NDTs. In this review, the nanodynamic potentiation strategies in terms of unique properties and universalities of NDTs are comprehensively outlined. We mainly summarize the current dilemmas faced by each NDT and the respective solutions. Meanwhile, the NDTs universalities-based potentiation strategies and NDTs-based combined treatments are elaborated. Finally, we conclude with a discussion of the key issues and challenges faced in the development and clinical transformation of NDTs.

Engineered Extracellular Vesicles to Enhance Antigen Presentation for Boosting Light-Driven Tumor Immunotherapy

Extracellular vesicles (EVs) have emerged as potential tools for tumor-target therapy accompanied with activating anticancer immune responses by serving as an integrated platform, but usually suffered from the limited cross presentation of tumor-associated antigen by dendritic cells (DCs). Here, a straightforward engineering strategy to construct heat shock proteins 70 (HSP70) highly expressed EVs incapsulated with Te nanoparticles (Te@EVsHSP70 ) for tumor photothermal therapy triggering improved immunotherapy is proposed. Tumor cells are firstly used as bioreactors for intracellular synthesis of Te nanoparticles, and NIR irradiation is subsequently introduced to upregulate the expression of HSP70 to give engineered Te@EVsHSP70 through exocytosis. Te@EVsHSP70 exhibits excellent photothermal performance and enhanced tumor antigen capture capability, which induces significant immunogenic death of tumor cells and improves DCs maturation both in vitro and in vivo. Thus, the engineered EVs demonstrate superior antitumor efficacy through photothermal effect and following provoked antitumor immune responses. This work provides a facile method to fabricate multifunctional EVs-based drug delivery system for improving photothermal-triggered tumor immunotherapy.

Recent theranostic applications of hydrogen peroxide-responsive nanomaterials for multiple diseases

It is well established that hydrogen peroxide (H2O2) is associated with the initiation and progression of many diseases. With the rapid development of nanotechnology, the diagnosis and treatment of those diseases could be realized through a variety of H2O2-responsive nanomaterials. In order to broaden the application prospects of H2O2-responsive nanomaterials and promote their development, understanding and summarizing the design and application fields of such materials has attracted much attention. This review provides a comprehensive summary of the types of H2O2-responsive nanomaterials including organic, inorganic and organic-inorganic hybrids in recent years, and focused on their specific design and applications. Based on the type of disease, such as tumors, bacteria, dental diseases, inflammation, cardiovascular diseases, bone injury and so on, key examples for above disease imaging diagnosis and therapy strategies are introduced. In addition, current challenges and the outlook of H2O2-responsive nanomaterials are also discussed. This review aims to stimulate the potential of H2O2-responsive nanomaterials and provide new application ideas for various functional nanomaterials related to H2O2.

High quantum efficiency ruthenium coordination complex photosensitizer for improved radiation-activated Photodynamic Therapy

Traditional external light-based Photodynamic Therapy (PDT)'s application is limited to the surface and minimal thickness tumors because of the inefficiency of light in penetrating deep-seated tumors. To address this, the emerging field of radiation-activated PDT (radioPDT) uses X-rays to trigger photosensitizer-containing nanoparticles (NPs). A key consideration in radioPDT is the energy transfer efficiency from X-rays to the photosensitizer for ultimately generating the phototoxic reactive oxygen species (ROS). In this study, we developed a new variant of pegylated poly-lactic-co-glycolic (PEG-PLGA) encapsulated nanoscintillators (NSCs) along with a new, highly efficient ruthenium-based photosensitizer (Ru/radioPDT). Characterization of this NP via transmission electron microscopy, dynamic light scattering, UV-Vis spectroscopy, and inductively coupled plasma mass-spectroscopy showed an NP size of 120 nm, polydispersity index (PDI) of less than 0.25, high NSCs loading efficiency over 90% and in vitro accumulation within the cytosolic structure of endoplasmic reticulum and lysosome. The therapeutic efficacy of Ru/radioPDT was determined using PC3 cell viability and clonogenic assays. Ru/radioPDT exhibited minimal cell toxicity until activated by radiation to induce significant cancer cell kill over radiation alone. Compared to protoporphyrin IX-mediated radioPDT (PPIX/radioPDT), Ru/radioPDT showed higher capacity for singlet oxygen generation, maintaining a comparable cytotoxic effect on PC3 cells.

Reprogramming of the tumor microenvironment using a PCN-224@IrNCs/D-Arg nanoplatform for the synergistic PDT, NO, and radiosensitization therapy of breast cancer and improving anti-tumor immunity

The low X-ray attenuation coefficient of tumor soft tissue and the hypoxic tumor microenvironment (TME) during radiation therapy (RT) of breast cancer result in RT resistance and thus reduced therapeutic efficacy. In addition, immunosuppression induced by the TME severely limits the antitumor immunity of radiation therapy. In this paper, we propose a PCN-224@IrNCs/D-Arg nanoplatform for the synergistic radiosensitization, photodynamic, and NO therapy of breast cancer that also boosts antitumor immunity (PCN = porous coordination network, IrNCs = iridium nanocrystals, D-Arg = D-arginine). The local tumors can be selectively ablated via reprogramming the tumor microenvironment (TME), photodynamic therapy (PDT) and NO therapy, and the presence of the high-Z element Ir that sensitizes radiotherapy. The synergistic execution of these treatment modalities also resulted in adapted antitumor immune response. The intrinsic immunomodulatory effects of the nanoplatform also repolarize macrophages toward the M1 phenotype and induce dendritic cell maturation, activating antitumor T cells to induce immunogenic cell death as demonstrated in vitro and in vivo. The nanocomposite design reported herein represents a new regimen for the treatment of breast cancer through TME reprogramming to exert a synergistic effect for effective cancer therapy and antitumor immunity.

Nanoparticles-based phototherapy systems for cancer treatment: Current status and clinical potential

Remarkable progress in phototherapy has been made in recent decades, due to its non-invasiveness and instant therapeutic efficacy. In addition, with the rapid development of nanoscience and nanotechnology, phototherapy systems based on nanoparticles or nanocomposites also evolved as an emerging hotspot in nanomedicine research, especially in cancer. In this review, first we briefly introduce the history of phototherapy, and the mechanisms of phototherapy in cancer treatment. Then, we summarize the representative development over the past three to five years in nanoparticle-based phototherapy and highlight the design of the innovative nanoparticles thereof. Finally, we discuss the feasibility and the potential of the nanoparticle-based phototherapy systems in clinical anticancer therapeutic applications, aiming to predict future research directions in this field. Our review is a tutorial work, aiming at providing useful insights to researchers in the field of nanotechnology, nanoscience and cancer.

Enhancement of Light and X-ray Charging in Persistent Luminescence Nanoparticle Scintillators Zn2SiO4:Mn2+, Yb3+, Li. ACS APPLIED MATERIALS & INTERFACES 2023;15:21228-21238. [PMID: 37078901 DOI: 10.1021/acsami.3c00664]

Persistent luminescence nanoparticle scintillators (PLNS) have been attempted for X-ray-induced photodynamic therapy (X-PDT) because persistent luminescence after ceasing radiation can make PLNS use less cumulative irradiation time and dose to generate the same amount of reactive oxygen species (ROS) compared with conventional scintillators to combat cancer cells. However, excessive surface defects in PLNS reduce the luminescence efficiency and quench the persistent luminescence, which is fatal to the efficacy of X-PDT. Herein, the PLNS of SiO₂@Zn₂SiO₄:Mn²⁺, Yb³⁺, Li⁺ was designed by the energy trap engineering and synthesized by a simple template method, which has excellent X-ray and UV-excited persistent luminescence and continuously tunable emission spectra from 520 to 550 nm. Its luminescence intensity and afterglow time are more than 7 times that of the reported Zn₂SiO₄:Mn²⁺ used for X-PDT. By loading a Rose Bengal (RB) photosensitizer, an effective persistent energy transfer from the PLNS to photosensitizer is observed even after the removal of X-ray irradiation. The X-ray dose of nanoplatform SiO₂@Zn₂SiO₄:Mn²⁺, Yb³⁺, Li⁺@RB in X-PDT of HeLa cancer cells was reduced to 0.18 Gy compared to the X-ray dose of 1.0 Gy for Zn₂SiO₄:Mn for X-PDT. This indicates that the Zn₂SiO₄:Mn²⁺, Yb³⁺, Li⁺ PLNS have great potential for X-PDT applications.

Catalytic nanotechnology of X-ray photodynamics for cancer treatments

Photodynamic therapy (PDT) has been applied in cancer treatment because of its high selectivity, low toxicity, and non-invasiveness. However, the limited penetration depth of the light still hampers from reaching deep-seated tumors. Considering the penetrating ability of high-energy radiotherapy, X-ray-induced photodynamic therapy (X-PDT) has evolved as an alternative to overcome tissue blocks. As the basic principle of X-PDT, X-rays stimulate the nanoparticles to emit scintillating or persistent luminescence and further activate the photosensitizers to generate reactive oxygen species (ROS), which would cause a series of molecular and cellular damages, immune response, and eventually break down the tumor tissue. In recent years, catalytic nanosystems with unique structures and functions have emerged that can enhance X-PDT therapeutic effects via an immune response. The anti-cancer effect of X-PDT is closely related to the following factors: energy conversion efficiency of the material, the radiation dose of X-rays, quantum yield of the material, tumor resistance, and biocompatibility. Based on the latest research in this field and the classical theories of nanoscience, this paper systematically elucidates the current development of the X-PDT and related immunotherapy, and highlights its broad prospects in medical applications, discussing the connection between fundamental science and clinical translation.

Coordination-Driven Self-Assembly Strategy-Activated Cu Single-Atom Nanozymes for Catalytic Tumor-Specific Therapy

How to optimize the enzyme-like catalytic activity of nanozymes to improve their applicability has become a great challenge. Herein, we present an l-cysteine (l-Cys) coordination-driven self-assembly strategy to activate polyvinylpyrrolidone (PVP)-modified Cu single-atom nanozymes MoOx-Cu-Cys (denoted as MCCP SAzymes) aiming at catalytic tumor-specific therapy. The Cu single atom content of MCCP can be rationally modulated to 10.10 wt %, which activates the catalase (CAT)-like activity of MoOx nanoparticles to catalyze the decomposition of H2O2 in acidic microenvironments to increase O2 production. Excitingly, the maximized CAT-like catalytic efficiency of MCCP is 138-fold higher than that of typical MnO2 nanozymes and exhibits 14.3-fold higher affinity than natural catalase, as demonstrated by steady-state kinetics. We verify that the well-defined l-Cys-Cu···O active sites optimize CAT-like activity to match the active sites of natural catalase through an l-Cys bridge-accelerated electron transfer from Cys-Cu to MoOx disclosed by density functional theory calculations. Simultaneously, the high loading Cu single atoms in MCCP also enable generation of •OH via a Fenton-like reaction. Moreover, under X-ray irradiation, MCCP converts O2 to 1O2 for cascading radiodynamic therapy, thereby facilitating the multiple reactive oxygen species (ROS) for radiosensitization to achieve substantial antitumor.

Enhanced radioluminescence of NaLuF4:Eu3+ nanoscintillators by terbium sensitization for X-ray imaging

NaLuF4:Eu3+ nanoscintillator with enhanced radioluminescence was boosted by the sensitization effect of Tb3+ on Eu3+ with an excellent X-ray scintillation performance, and further applied in X-ray imaging with high contrast for different samples.

Image-Guided Precision Treatments

Chemotherapy, radiotherapy, and surgery are traditional cancer treatments, which usually produce unpredictable side effects and potential risks to normal healthy organs/tissues. Thus, safe and reliable treatment strategies are urgently required for maximized therapeutic efficiency to lesions and minimized risks to healthy regions. To this end, molecular imaging is responsible to undertake a specific targeting therapy. Besides that, the image guidance as a precision visualized approach for real-time in situ evaluations as well as an intraoperational navigation approach has earned attractive attention in the past decade. Along with the rapid development of multifunctional micro-/nanobiomaterials, versatile cutting-edge and advanced therapy strategies (e.g., thermal therapy, dynamic therapy, gas therapy, etc.) have been achieved and greatly contributed to the image-guided precision treatments in every aspect. Therefore, this chapter aims to discuss about both traditional and advanced cancer treatments and especially to elucidate the important roles that visualized medicine has been playing in the image-guided precision treatments.

Alternative Strategy to Optimize Cerium Oxide for Enhanced X-ray-Induced Photodynamic Therapy

The emergence of X-ray-induced photodynamic therapy (X-PDT) holds tremendous promise for clinical deep-penetrating cancer therapy. However, the clinical application of X-PDT in cancer treatment is still limited due to the hypoxic property of cancerous tissue, the inherent antioxidant system of tumor cells, and the difficulty in matching the absorption spectra of photosensitizers. Herein, a versatile core-shell radiosensitizer (SCNPs@DMSN@CeO_x-PEG, denoted as SSCP) was elaborately designed and constructed to enhance X-PDT by coating tunable mesoporous silica on nanoscintillators, followed by embedding the cerium oxide nanoparticles in situ. The obtained SSCP radiosensitizer demonstrated a distinct blue-shift in the ultraviolet light region, so that it could perfectly absorb the ultraviolet light converted by the SCNPs core, resulting in the formation of photoinduced electron-hole (e^--h⁺) pairs separation to generate reactive oxygen species (ROS). In addition, the cerium oxide exhibits high glutathione consumption to heighten ROS accumulation, and catalase-like activity to alleviate the hypoxia, which further enhances the efficiency of radiotherapy. Benefiting from the abundant Lu and Ce elements, the computed tomography imaging performance of SSCP is about 3.79-fold that of the clinical contrast agent (iohexol), which has great potential in both preclinical imaging and clinical translation.

Recent Progress and Trends in X-ray-Induced Photodynamic Therapy with Low Radiation Doses

The prominence of photodynamic therapy (PDT) in treating superficial skin cancer inspires innovative solutions for its congenitally deficient shadow penetration of the visible-light excitation. X-ray-induced photodynamic therapy (X-PDT) has been proven to be a successful technique in reforming the conventional PDT for deep-seated tumors by creatively utilizing penetrating X-rays as external excitation sources and has witnessed rapid developments over the past several years. Beyond the proof-of-concept demonstration, recent advances in X-PDT have exhibited a trend of minimizing X-ray radiation doses to quite low values. As such, scintillating materials used to bridge X-rays and photosensitizers play a significant role, as do diverse well-designed irradiation modes and smart strategies for improving the tumor microenvironment. Here in this review, we provide a comprehensive summary of recent achievements in X-PDT and highlight trending efforts using low doses of X-ray radiation. We first describe the concept of X-PDT and its relationships with radiodynamic therapy and radiotherapy and then dissect the mechanism of X-ray absorption and conversion by scintillating materials, reactive oxygen species evaluation for X-PDT, and radiation side effects and clinical concerns on X-ray radiation. Finally, we discuss a detailed overview of recent progress regarding low-dose X-PDT and present perspectives on possible clinical translation. It is expected that the pursuit of low-dose X-PDT will facilitate significant breakthroughs, both fundamentally and clinically, for effective deep-seated cancer treatment in the near future.

Investigation of the photoluminescent properties, scintillation behaviour and toxicological profile of various magnesium tungstate nanoscale motifs

We have synthesized several morphologies and crystal structures of MgWO₄ using a one-pot hydrothermal method, producing not only monoclinic stars and large nanoparticles but also triclinic wool balls and sub-10 nm nanoparticles. Herein we describe the importance of reaction parameters in demonstrating morphology control of as-prepared MgWO₄. Moreover, we correlate structure and composition with the resulting photoluminescence and radioluminescence properties. Specifically, triclinic-phase samples yielded a photoluminescence emission of 421 nm, whereas monoclinic-phase materials gave rise to an emission maximum of 515 nm. The corresponding radioluminescence data were characterized by a broad emission peak, located at 500 nm for all samples. Annealing the wool balls and sub-10 nm particles to transform the crystal structure from a triclinic to a monoclinic phase yielded a radioluminescence (RL) emission signal that was two orders of magnitude greater than that of their unannealed counterparts. Finally, to confirm the practical utility of these materials for biomedical applications, a series of sub-10 nm particles, including as-prepared and annealed samples, were functionalized with biocompatible PEG molecules, and subsequently were found to be readily taken up by various cell lines as well as primary cultured hippocampal neurons with low levels of toxicity, thereby highlighting for the first time the potential of this particular class of metal oxides as viable and readily generated platforms for a range of biomedical applications.

X-ray triggered pea-shaped LuAG:Mn/Ca nano-scintillators and their applications for photodynamic therapy

Photodynamic therapy (PDT) is a new minimally invasive technology for disease diagnosis and treatment. However, the biological tissue attenuation of visible light renders the depth of its penetration in tissues quite modest, which significantly restricts its therapeutic applicability. Therefore, it is an essential but yet a difficult task to enhance the X-ray sensitization impact while concurrently limiting the tissue scattering by the rational design of novel biological vectors. Herein, a novel Lu3Al5O12:Mn/Ca-Ce6@SiO2 nanoparticle system (LAMCCS) based on a pea-shaped LuAG:Mn/Ca nano-scintillator (LAMC) activating photosensitizer agent (Ce6) was designed. Due to the high radiosensitization of LAMC nano-scintillators and efficient energy conversion efficiency between LAMC and Ce6, more singlet oxygen (1O2) could be generated to efficiently damage DNA fragments and reveal a good effect of inhibiting the long-term proliferation of tumor cells in vitro. Significantly, synergistic therapy with PDT/radiotherapy (RT) and from LAMCCS nanocomposites may still maintain a high tumor growth inhibition rate of 72% than single RT of 10% in vivo. Owing to their excellent ability for X-ray sensitization and energy conversion, LAMCCS nanocomposites may have significant tumor growth suppression rates under lower X-ray dose irradiation due to their outstanding X-ray sensitization and energy conversion capabilities, which may open up a new avenue for the advancement of cancer therapy.

Engineered extracellular vesicles and their mimetics for cancer immunotherapy

Extracellular vesicles (EVs) are heterogeneous membranous vesicles secreted by living cells that are involved in many physiological and pathological processes as intermediaries for intercellular communication and molecular transfer. Recent studies have shown that EVs can regulate the occurrence and development of tumors by transferring proteins, lipids and nucleic acids to immune cells as signaling molecules. As a new diagnostic biomarker and drug delivery system, EVs have broad application prospects in immunotherapy. In addition, the breakthrough of nanotechnology has promoted the development and exploration of engineered EVs for immune-targeted therapy. Herein, we review the uniqueness of EVs in immune regulation and the engineering strategies used for immunotherapy and highlight the logic of their design through typical examples. The present situation and challenges of clinical transformation are discussed, and the development prospects of EVs in immunotherapy are proposed. The goal of this review is to provide new insights into the design of immune-regulatory EVs and expand their application in cancer immunotherapy.

Copper-based nanomaterials for cancer theranostics

Copper-based nanomaterials (Cu-based NMs) with favorable biocompatibility and unique properties have attracted the attention of many biomedical researchers. Cu-based NMs are one of the most widely studied materials in cancer treatment. In recent years, great progress has been made in the field of biomedicine, especially in the treatment and diagnosis of tumors. This review begins with the classification of Cu-based NMs and the recent synthetic strategies of Cu-based NMs. Then, according to the abundant and special properties of Cu-based NMs, their application in biomedicine is summarized in detail. For biomedical imaging, such as photoacoustic imaging, positron emission tomography imaging, and multimodal imaging based on Cu-based NMs are summarized, as well as strategies to improve the diagnostic effectiveness. Moreover, a series of unique structures and functions as well as the underlying property activity relationship of Cu-based NMs were shown to highlight their promising therapeutic performance. Cu-based NMs have been widely used in monotherapies, such as photothermal therapy (PTT) and chemodynamic therapy (CDT). Moreover, the sophisticated design in composition, structure, and surface fabrication of Cu-based NMs can endow these NMs with more modalities in cancer diagnosis and therapy. To further improve the efficiency of cancer treatment, combined therapy based on Cu-based NMs was introduced in detail. Finally, the challenges, critical factors, and future prospects for the clinical translation of Cu-based NMs as multifunctional theranostic agents were also considered and discussed. The aim of this review is to provide a better understanding and key consideration for the rational design of this increasingly important new paradigm of Cu-based NMs as theranostic agents. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Catalytic radiosensitization: Insights from materials physicochemistry

Radiotherapy is indispensable in clinical cancer treatment, but because both tumor and normal tissues have similar sensitivity to X-rays, their clinical curative effect is intrinsically limited. Advanced nanomaterials and nanotechnologies have been developed for radiotherapy sensitization, typically employing high atomic number (high-Z) materials to enhance the energy deposition of X-rays in tumor tissues, but the efficiency is largely limited by the toxicity of heavy metals. A new and promising approach for radiosensitization is catalytic radiosensitization, which takes advantage of the catalytic activity of nanomaterials triggered by radiation. The efficiency of catalytic radiosensitization can be greatly enhanced by electron modulation and energy conversion of nanocatalysts upon X-ray irradiation, further enhancing the clinical curative effect. In this review, we highlight the challenges and opportunities in cancer radiosensitization, discuss novel approaches to catalytic radiosensitization, and finally describe the development of catalytic radiosensitization based on an in-depth understanding of radio-nano interactions and catalysis-biological interactions.

Recent Advance of Nanomaterial-Mediated Tumor Therapies in the Past Five Years

Cancer has posed a major threat to human life and health with a rapidly increasing number of patients. The complexity and refractory of tumors have brought great challenges to tumor treatment. In recent years, nanomaterials and nanotechnology have attracted more attention and greatly improved the efficiency of tumor therapies and significantly prolonged the survival period, whether for traditional tumor treatment methods such as radiotherapy, or emerging methods, such as phototherapy and immunotherapy, sonodynamic therapy, chemodynamic therapy and RNA interference therapeutics. Various monotherapies have obtained positive results, while combination therapies are further proposed to prevent incomplete eradication and recurrence of tumors, strengthen tumor killing efficacy with minimal side effects. In view of the complementary promotion effects between different therapies, it is vital to utilize nanomaterials as the link between monotherapies to achieve synergistic performance. Further development of nanomaterials with efficient tumor-killing effect and better biosafety is more in line with the needs of clinical treatment. In a word, the development of nanomaterials provides a promising way for tumor treatment, and here we will review the emerging nanomaterials towards radiotherapy, phototherapy and immunotherapy, and summarized the developed nanocarriers applied for the tumor combination therapies in the past 5 years, besides, the advances of some other novel therapies such as sonodynamic therapy, chemodynamic therapy, and RNA interference therapeutics have also been mentioned.

Recent advances in upconversion nanoparticle-based nanocomposites for gas therapy

Gas therapy has attracted wide attention for the treatment of various diseases. However, a controlled gas release is highly important for biomedical applications. Upconversion nanoparticles (UCNPs) can precisely convert the long wavelength of light to ultraviolet/visible (UV/Vis) light in gas therapy for the controlled gas release owing to their unique upconversion luminescence (UCL) ability. In this review, we mainly summarized the recent progress of UCNP-based nanocomposites in gas therapy. The gases NO, O2, H2, H2S, SO2, and CO play an essential role in the physiological and pathological processes. The UCNP-based gas therapy holds great promise in cancer therapy, bacterial therapy, anti-inflammation, neuromodulation, and so on. Furthermore, the limitations and prospects of UCNP-based nanocomposites for gas therapy are also discussed.

Bacterially Synthesized Tellurium Nanorods for Elimination of Advanced Malignant Tumor by Photothermal Immunotherapy

Probiotic Escherichia coli Nissle 1917 (EcN) are employed as a bioreactor for intracellularly synthesizing tellurium nanorods (TeNRs) providing a biohybrid therapeutic platform (Te@EcN) for the elimination of advanced malignant tumor by photothermal immunotherapy. Te@EcN is found to possess superior photothermal property upon near-infrared irradiation, and can efficiently accumulate and retain in tumors, although EcN loses proliferation ability after the synthesis of TeNRs, thus inducing considerable immunogenic tumor cell death. Under co-stimulation by EcN acting as immunoadjuvants, maturation of dendritic cells and priming of cytotoxic T cells are largely promoted. In addition, Te@EcN can reprogram tumor-associated macrophages to ameliorate the immunosuppressive tumor microenvironment. Thus, tumor metastasis and recurrence can be efficiently suppressed. Most importantly, owing to the non-pathogenicity of probiotic EcN and their non-proliferative characteristics after TeNRs synthesis, Te@EcN is found to be rapidly metabolized and cleared from the normal tissues, showing very slight acute side effects in healthy mice even at a relatively high administration dose. Therefore, the proposed combined therapeutic strategy based on bacteria-synthesized TeNRs may find great potential in improving bacteria-mediated tumor therapy with increased antitumor efficacy and reduced toxicity.