Selenium-Containing Nanoparticles Combine the NK Cells Mediated Immunotherapy with Radiotherapy and Chemotherapy

Protein Immobilization Inspired Lysosomal Disruption for Efficient Nuclear Drug Delivery

The high metabolism and excessive growth of tumor cells result in the development of a tumor microenvironment (TME) and enhanced lysosomal activity within the cells, which can eliminate chemotherapeutics. Consequently, the design of nanocarriers that respond to TME and target tumor cell lysosomes represents an optimal strategy to enhance drug specificity and utilization efficiency. Herein, inspired by protein immobilization, a dual-responsive supramolecular nanomedicine FPA/DOX is developed for specifically targeting the TME and tumor cell lysosomes. Upon hypoxia and acidic response, FPA/DOX exposes benzaldehyde groups that engage with amino groups on lysosomal proteins by protein covalent immobilization reaction─an imidization condensation reaction, leading to protein denaturation and inactivation and inducing lysosomal membrane permeabilization (LMP). This LMP process not only triggers lysosomal-dependent cell death (LDCD) but also facilitates the rapid translocation of released DOX into the cell nucleus. In vitro experiments have demonstrated that the tumor cell toxicity of FPA/DOX is 4.2 times that of free DOX. Additionally, in vivo studies have verified the high biosafety of FPA/DOX, with a remarkable tumor inhibition rate of 95.27%. In summary, the lysosomal disruption inspired by protein immobilization has pioneered an approach for tumor treatment and holds great potential in biomedical applications.

Reactive Oxygen Species-Responsive Polymer Drug Delivery System Targeted Oxidative Stressed Colon Cells to Ameliorate Colitis

Ulcerative colitis (UC) is a chronic inflammatory condition that imposes a huge healthcare burden globally. The inflamed colon is marked by an abundance of positively charged proteins, increased reactive oxygen species (ROS), a disrupted intestinal barrier, and an imbalanced gut microbiome. Leveraging these features, we designed a negatively charged ROS-responsive nanocarrier using diselenide-bond-modified carboxymethyl cellulose (CMC) for the targeted delivery of curcumin, a natural ROS-scavenging antioxidant, to treat UC. The design rationale encompasses three key aspects: (1) the biocompatible and biodegradable CMC matrix stabilizes curcumin during digestion; (2) the diselenide bonds enable redox-triggered curcumin release at inflammatory sites, ensuring precise therapeutic action; and (3) the negative charge of the nanoparticles enhances interactions with positively charged proteins in inflamed colon tissues, improving site-specific accumulation. Experimental validation confirmed these design principles, demonstrating that the resulting nanoparticles effectively preserve curcumin during digestion and enable the ROS-responsive release of curcumin at inflamed sites. Additionally, these nanoparticles interact effectively with folic acid receptors (positively charged proteins) that are overexpressed on oxidatively stressed cell membranes, leading to specific accumulation in colitis tissue. Subsequently, the nanoparticles scavenge excessive ROS, restore intestinal barrier function, and modulate the gut microbiota. These synergistic actions collectively contribute to significant mitigation of colitis symptoms in both preventive and therapeutic regimens, suggesting a promising alternative therapeutic approach for UC.

Advances in cancer immunotherapy: historical perspectives, current developments, and future directions

Cancer immunotherapy, encompassing both experimental and standard-of-care therapies, has emerged as a promising approach to harnessing the immune system for tumor suppression. Experimental strategies, including novel immunotherapies and preclinical models, are actively being explored, while established treatments, such as immune checkpoint inhibitors (ICIs), are widely implemented in clinical settings. This comprehensive review examines the historical evolution, underlying mechanisms, and diverse strategies of cancer immunotherapy, highlighting both its clinical applications and ongoing preclinical advancements. The review delves into the essential components of anticancer immunity, including dendritic cell activation, T cell priming, and immune surveillance, while addressing the challenges posed by immune evasion mechanisms. Key immunotherapeutic strategies, such as cancer vaccines, oncolytic viruses, adoptive cell transfer, and ICIs, are discussed in detail. Additionally, the role of nanotechnology, cytokines, chemokines, and adjuvants in enhancing the precision and efficacy of immunotherapies were explored. Combination therapies, particularly those integrating immunotherapy with radiotherapy or chemotherapy, exhibit synergistic potential but necessitate careful management to reduce side effects. Emerging factors influencing immunotherapy outcomes, including tumor heterogeneity, gut microbiota composition, and genomic and epigenetic modifications, are also examined. Furthermore, the molecular mechanisms underlying immune evasion and therapeutic resistance are analyzed, with a focus on the contributions of noncoding RNAs and epigenetic alterations, along with innovative intervention strategies. This review emphasizes recent preclinical and clinical advancements, with particular attention to biomarker-driven approaches aimed at optimizing patient prognosis. Challenges such as immunotherapy-related toxicity, limited efficacy in solid tumors, and production constraints are highlighted as critical areas for future research. Advancements in personalized therapies and novel delivery systems are proposed as avenues to enhance treatment effectiveness and accessibility. By incorporating insights from multiple disciplines, this review aims to deepen the understanding and application of cancer immunotherapy, ultimately fostering more effective and widely accessible therapeutic solutions.

Tumor Microenvironment-Responsive Polymer Delivery Platforms for Cancer Therapy

Most chemotherapeutic and bioimaging agents struggle with inadequate bioavailability, primarily due to their limited biocompatibility and lack of specificity in targeting, leading to low or decreased anticancer efficacy and inaccurate imaging. To surmount these obstacles, the development of stimuli-responsive polymer delivery platforms, predominantly leveraging the tumor microenvironment (TME), has emerged as a promising strategy. Therapeutic and diagnostic agents can be released controllably at the tumor site by virtue of the bond cleavage or hydrophobic to hydrophilic transformation of TME-sensitive linkages in TME-responsive systems, thus augmenting cancer treatment and imaging precision, while simultaneously attenuating the damage to healthy tissues and false imaging signals caused by non-specific drug leakage. In this comprehensive review, we scrutinize recent studies of TME-responsive polymer delivery platforms, encompassing pH-, ROS-, GSH-, enzyme-, and hypoxia-responsive vectors, significantly from the perspective of their molecular design and responsive mechanism, and further summarizing their bio-application in drug delivery and diagnostic imaging. Moreover, this review encapsulates the critical challenges and offers an insightful perspective on the future prospects of TME-responsive polymer delivery platforms in terms of molecular and vector design.

Selenium-containing compounds, selenium nanoparticles and selenoproteins in the prevention and treatment of lung cancer

THE OBJECTIVE

Is to review the latest data on the role of key organic and inorganic compounds of the essential trace element selenium, selenium-containing nanocomposites and nanoparticles, and selenoproteins in lung cancer therapy.

OBJECT OF RESEARCH

Sodium selenite, methylselenic acid, selenomethionine, selenium nanoparticles, mammalian selenoproteins KEY OBJECTIVES:: To describe the molecular mechanisms of the cytotoxic effect of sodium selenite, methylselenic acid and selenomethionine on lung cancer cells, to discuss the latest advances in lung cancer nanomedicine using selenium-based nanoparticles and nanocomposites and to assess the prospects for creating antitumor drugs based on them, to assess the role of selenoproteins in the progression or inhibition of lung cancer and to study the molecular mechanisms of such regulation CONCLUSIONS:: This review provides a complete picture of the role of selenium and selenium-containing agents of various natures in the regulation of carcinogenesis and therapy of lung cancer, which significantly complements the fundamental data on the functions of these compounds, on the molecular mechanisms of regulation of processes associated with lung cancer. This knowledge provides insight into the latest developments and future prospects in the treatment and prevention of lung cancer with the active participation of the trace element selenium.

The role and mechanism of selenium in the prevention and progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most prevalent form of liver cancer. Despite notable advancements in therapeutic strategies, HCC continues to pose significant public health challenges due to its rising incidence and high mortality rates worldwide. Selenium is an essential trace element that playing a critical role in human health. Recent studies have highlighted its potential preventive and therapeutic benefits in the context of HCC. However, some in vitro and in vivo investigations have yielded inconsistent results, and the mechanisms by which selenium influences HCC are still not completely clear. This review begins by providing an extensive evaluation of the effects and mechanisms of selenium on the primary risk factors associated with HCC, including viral infections, metabolic abnormalities, and lifestyle factors. Subsequently, we outline the roles and mechanisms by which selenium influences the proliferation, metastasis, and immune microenvironment of HCC. Finally, we emphasize the imperative for further investigation into the optimal dosage and forms of selenium, as well as its effects on the HCC microenvironment, to inform the development of effective clinical strategies. This review thus provides a foundational framework for the potential clinical application of selenium in the treatment of HCC.

Cellular uptake mechanisms of a diselenide-based ROS-responsive nanocarrier in oxidatively stressed colon cells

Here, we demonstrate that a diselenide-based ROS-responsive nanocarrier exhibits a highly sensitive response to ROS and excellent ROS scavenging activity. Mechanism studies indicate that it can be efficiently taken up by oxidatively stressed colon cells through folate receptor-mediated endocytosis, underscoring its potential for targeted drug delivery in treating colon diseases.

Recent Insights into Bioactive Dichalcogen Derivatives: From Small Molecules to Complex Materials

Organodichalcogenides have been explored due to their therapeutic properties. They have been demonstrated to be active against several diseases such as cancer, bacteria, viruses, parasites, or neurological diseases. Among the different classes of dichalcogenides, disulfide derivatives have been widely studied, and many studies cover their therapeutical use. For this reason, this review includes the latest studies of diselenides and ditellurides derivatives with biological applications. With this aim, several bioactive small molecules containing the diselenide or ditelluride bond in their structure have been discussed. Furthermore, it should be highlighted that, in recent years, there has been an increasing interest in the development of nanomaterials for drug delivery due to their therapeutic advantages. In this context, diselenide and ditelluride-containing nanocarriers have emerged as novel approaches. The information compiled in this review includes small molecules and more complex materials containing diselenide or ditelluride bonds in their structure for different therapeutical applications, which could be helpful for the further development of novel drugs for the treatment of different diseases.

Synthesis and Biomedical Based Applications of Selenium Nanoparticles: A Comprehensive Review

Selenium nanoparticles (SeNPs) captivate researchers due to their unique properties and promise in biomedicine. This review explores SeNP synthesis methods, emphasizing how they influence functionality in diverse applications. Chemical, physical, and biological approaches tailor SeNP size, shape, and surface chemistry, impacting their biocompatibility and potential for drug delivery, imaging, and therapy. SeNPs' remarkable electrochemical and optical properties position them for advancements in biosensing and diagnostics. However, challenges in consistent production, large-scale synthesis, and potential toxicity demand attention. We provide a concise analysis of current SeNP research, encompassing synthesis strategies, characterization techniques, and a broad spectrum of biomedical applications, while also addressing ongoing challenges and future directions in this rapidly evolving field.

Graphical Abstract

The multifaceted biological roles of Se NPs encompass orchestrating cellular processes, targeted drug delivery, enhancing chemotherapy efficacy, and providing protective effects against treatment-related toxicity.

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.

Metal-Protein Hybrid Materials: Unlocking New Frontiers in Biomedical Applications

Metal-protein hybrid materials represent a novel class of functional materials that exhibit exceptional physicochemical properties and tunable structures, rendering them remarkable applications in diverse fields, including materials engineering, biocatalysis, biosensing, and biomedicine. The design and development of multifunctional and biocompatible metal-protein hybrid materials have been the subject of extensive research and a key aspiration for practical applications in clinical settings. This review provides a comprehensive analysis of the design strategies, intrinsic properties, and biomedical applications of these hybrid materials, with a specific emphasis on their potential in cancer therapy, drug and vaccine delivery, antibacterial treatments, and tissue regeneration. Through rational design, stable metal-protein hybrid materials can be synthesized using straightforward methods, enabling them with therapeutic, delivery, immunomodulatory, and other desired functionalities. Finally, the review outlines the existing limitations and challenges associated with metal-protein hybrid materials and evaluates their potential for clinical translation, providing insights into their practical implementation within biomedical applications.

Configuration-Mediated Efficient Non-Radiative Transition for R848-Assisted Photothermal Immunotherapy to Inhibit Tumor Growth and Metastasis by An In Situ Tumor Vaccine Strategy

Cancer metastasis remains a critical factor contributing to the current limitations in cancer treatment. Photothermal immunotherapy has emerged as a safe and potent therapeutic approach, demonstrating the capability to suppress tumor growth and metastasis. While researchers have extensively investigated various structural modifications to enhance photothermal conversion performance, the influence of molecular configuration has received comparatively limited attention. In this study, we synthesized two isomers, CZTBT and LVTBT, which possessed distinct configurations. LVTBT, characterized by a flatter molecular configuration, exhibited an extended absorption wavelength and a higher molar extinction coefficient. Its excited state facilitated stronger rotation for non-radiative transitions, leading to a high photothermal conversion efficiency (PCE) of 36.3 %. When combined with R848, LVTBT@R848 nanoparticles (NPs)-mediated photothermal immunotherapy functioned as an in situ tumor vaccine, promoting the maturation of dendritic cells (DCs), T cell infiltration, and the differentiation of natural killer (NK) cells and memory T cells, thereby activating the strong immune response. Consequently, it significantly inhibited the growth of both primary and distant tumors, while also limiting lung metastasis. In summary, this study proposed a configuration-mediated non-radiative transition strategy for efficient photothermal immunotherapy, advancing the frontiers of organic photothermal agents (OPTAs) design and synthesis.

Selenium Nanoparticles Synergize with a KRAS Nanovaccine against Breast Cancer

Selenium (Se) is an element crucial for human health, known for its anticancer properties. Although selenium nanoparticles (SeNPs) have shown lower toxicity and higher biocompatibility than other Se compounds, bare SeNPs are unstable in aqueous solutions. In this study, several materials, including bovine serum albumin (BSA), chitosan, polymethyl vinyl ether-alt-maleic anhydride, and tocopherol polyethylene glycol succinate, are explored to develop stable SeNPs and further evaluate their potential as candidates for cancer treatment. All optimized SeNP are spherical, <100 nm, and with a narrow size distribution. BSA-stabilized SeNPs produced under acidic conditions present the highest stability in medium, plasma, and at physiological pH, maintaining their size ≈50-60 nm for an extended period. SeNPs demonstrate enhanced toxicity in cancer cell lines while sparing primary human dermal fibroblasts, underscoring their potential as effective anticancer agents. Moreover, the combination of BSA-SeNPs with a nanovaccine results in a strong tumor growth reduction in an EO771 breast cancer mouse model, demonstrating a three-fold decrease in tumor size. This synergistic anticancer effect not only highlights the role of SeNPs as effective anticancer agents but also offers valuable insights for developing innovative combinatorial approaches using SeNPs to improve the outcomes of cancer immunotherapy.

Covalent Modification of Selenium in Polysaccharide Enhances Immunoregulation Activity via the TLR4-Mediated MAPK/NF-κB Signaling Pathway

Selenium (Se) is a crucial trace element that demonstrates significant immunomodulatory effects, which are attributed to the variability in its valence states and metabolic pathways. To investigate the Se-related immunoregulatory effects, locust bean gum (LBG), a typical galactomannan, was selenized by employing deep eutectic solvents (DESs) as high-efficiency solvents to obtain Se-covalent modified LBG (SeLBGs) with similar molecular mass and different Se contents (SeLBGL, 1049.57 and SeLBGH, 4926.54 μg/g). After introducing selenite into LBG, SeLBGs display greater immunomodulatory activities by activating MAPKs and NF-κB signaling pathways compared with LBG and Se compounds (Se-Met, Na2SeO3, and SeNPs) at the same Se equivalent, which are confirmed by their higher cell viability, phagocytic activity, secretion of cytokines, and protein expression. In addition, molecular docking and molecular dynamics suggest that SeLBG has the potential to induce dimerization of subunits and activate toll-like receptors (TLRs). By employing the specific receptor inhibitors strategy, it is confirmed that the combination of Se and LBG enhances TLR2/4 recognition according to the results of cytokine secretion and MAPKs/NF-κB pathway-related protein expression. These findings underscore the role of Se in pattern receptor recognition and the potential of Se-enriched ingredients in various functions.

Living Cell-Mediated Self-Assembly: From Monomer Design and Morphology Regulation to Biomedical Applications

The self-assembly of molecules into highly ordered architectures is a ubiquitous and natural process, wherein molecules spontaneously organize into large structures to perform diverse functions. Drawing inspiration from the formation of natural nanostructures, cell-mediated self-assembly has been developed to create functional assemblies both inside and outside living cells. These techniques have been employed to regulate the cellular world by leveraging the dynamic intracellular and extracellular microenvironment. This review highlights the recent advances and future trends in living cell-mediated self-assembly, ranging from their cytocompatible monomer designs, synthetic strategies, and morphological control to functional applications. The assembly behaviors are also discussed based on the dimensionality of the self-assembled morphologies from zero to three dimensions. Finally, this review explores its promising potential for biomedical applications, clarifying the relationship between initial morphological regulation and the therapeutic effects of subsequent artificial assemblies. Through rationally designing molecular structures and precisely controlling assembly morphologies, living cell mediated self-assembly would provide an innovative platform for executing biological functions.

Cleavage of Homonuclear Chalcogen-Chalcogen Bonds in a Hybrid Platform in Response to X-Ray Radiation Potentiates Tumor Radiochemotherapy

Chalcogens are used as sensitive redox-responsive reagents in tumor therapy. However, chalcogen bonds triggered by external ionizing radiation, rather than by internal environmental stimuli, enable site-directed and real-time drug degradation in target lesions. This approach helps to bypass chemoresistance and global systemic toxicity, presenting a significant advancement over traditional chemoradiotherapy. In this study, we fabricated a hybrid monodisperse organosilica nanoprodrug based on homonuclear single bonds (disulfide bonds (S-S, approximately 240 kJ/mol), diselenium bonds (Se-Se, approximately 172 kJ/mol), and tellurium bonds (Te-Te, 126 kJ/mol)), including ditelluride-bond-bridged MONs (DTeMSNs), diselenide-bond-bridged MONs (DSeMSNs) and disulfide-bond-bridged MONs (DSMSNs). The results demonstrated that differences in electronegativities and atomic radii influenced their oxidation sensitivities and reactivities. Tellurium, with the lowest electronegativity, showed the highest sensitivity, followed by selenium and sulfur. DTeMSNs exhibited highly responsive cleavage upon exposure to X-rays, resulting in oxidation to TeO3 2-. Furthermore, chalcogen-hybridized organosilica was loaded with manganese ions (Mn2+) to enhance the release of Mn2+ during radiotherapy, thereby activating the the stimulator of interferon genes (STING) pathway and enhancing the tumor immune response to inhibit tumor growth. This investigation of hybrid organosilica deepens our understanding of chalcogens response characteristics to radiotherapy and enriches the design principles for nanomedicine based on prodrugs.

Peptides as Versatile Regulators in Cancer Immunotherapy: Recent Advances, Challenges, and Future Prospects

The emergence of effective immunotherapies has revolutionized therapies for many types of cancer. However, current immunotherapy has limited efficacy in certain patient populations and displays therapeutic resistance after a period of treatment. To address these challenges, a growing number of immunotherapy drugs have been investigated in clinical and preclinical applications. The diverse functionality of peptides has made them attractive as a therapeutic modality, and the global market for peptide-based therapeutics is witnessing significant growth. Peptides can act as immunotherapeutic agents for the treatment of many malignant cancers. However, a systematic understanding of the interactions between different peptides and the host's immune system remains unclear. This review describes in detail the roles of peptides in regulating the function of the immune system for cancer immunotherapy. Initially, we systematically elaborate on the relevant mechanisms of cancer immunotherapy. Subsequently, we categorize peptide-based nanomaterials into the following three categories: peptide-based vaccines, anti-cancer peptides, and peptide-based delivery systems. We carefully analyzed the roles of these peptides in overcoming the current barriers in immunotherapy, including multiple strategies to enhance the immunogenicity of peptide vaccines, the synergistic effect of anti-cancer peptides in combination with other immune agents, and peptide assemblies functioning as immune stimulators or vehicles to deliver immune agents. Furthermore, we introduce the current status of peptide-based immunotherapy in clinical applications and discuss the weaknesses and future prospects of peptide-based materials for cancer immunotherapy. Overall, this review aims to enhance comprehension of the potential applications of peptide-based materials in cancer immunotherapy and lay the groundwork for future research and clinical applications.

Recent advances in reactive oxygen species (ROS)-responsive drug delivery systems for photodynamic therapy of cancer

Reactive oxygen species (ROS)-responsive drug delivery systems (DDSs) have garnered significant attention in cancer research because of their potential for precise spatiotemporal drug release tailored to high ROS levels within tumors. Despite the challenges posed by ROS distribution heterogeneity and endogenous supply constraints, this review highlights the strategic alliance of ROS-responsive DDSs with photodynamic therapy (PDT), enabling selective drug delivery and leveraging PDT-induced ROS for enhanced therapeutic efficacy. This review delves into the biological importance of ROS in cancer progression and treatment. We elucidate in detail the operational mechanisms of ROS-responsive linkers, including thioether, thioketal, selenide, diselencide, telluride and aryl boronic acids/esters, as well as the latest developments in ROS-responsive nanomedicines that integrate with PDT strategies. These insights are intended to inspire the design of innovative ROS-responsive nanocarriers for enhanced cancer PDT.

ROS-sensitive PD-L1 siRNA cationic selenide nanogels for self-inhibition of autophagy and prevention of immune escape

In the field of cancer therapy, inhibiting autophagy has emerged as a promising strategy. However, pharmacological disruption of autophagy can lead to the upregulation of programmed death-ligand 1 (PD-L1), enabling tumor immune evasion. To address this issue, we developed innovative ROS-responsive cationic poly(ethylene imine) (PEI) nanogels using selenol chemistry-mediated multicomponent reaction (MCR) technology. This procedure involved simple mixing of low-molecular-weight PEI (LMW PEI), γ-selenobutylacetone (γ-SBL), and poly(ethylene glycol) methacrylate (PEGMA). Through high-throughput screening, we constructed a library of AxSeyOz nanogels and identified the optimized A1.8Se3O0.5/siPD-L1 nanogels, which exhibited a size of approximately 200 nm, excellent colloidal stability, and the most effective PD-L1 silencing efficacy. These nanogels demonstrated enhanced uptake by tumor cells, excellent oxidative degradation ability, and inhibited autophagy by alkalinizing lysosomes. The A1.8Se3O0.5/siPD-L1 nanogels significantly downregulated PD-L1 expression and increased the expression of major histocompatibility complex class I (MHC-I), resulting in robust proliferation of specific CD8+ T cells and a decrease in MC38 tumor growth. As a result, the A1.8Se3O0.5/siPD-L1 nanogels inhibited tumor growth through self-inhibition of autophagy, upregulation of MHC-I, and downregulation of PD-L1. Designed with dynamic diselenide bonds, the A1.8Se3O0.5/siPD-L1 nanogels showed synergistic antitumor efficacy through self-inhibition of autophagy and prevention of immune escape.

Se-incorporated polycaprolactone spherical polyhedron enhanced vitamin B2 loading and prolonged release for potential application in proliferative skin disorders

Development of novel drug vehicles for vitamin B2 (VitB2) delivery is very important for designing controllable release system to improve epidermal growth and bone metabolism. In this work, selenium (Se)-incorporated polycaprolactone (PCL) spherical polyhedrons are successfully synthesized via a single emulsion solvent evaporation method which is utilized to load VitB2 to fabricate cell-responsive Se-PCL@VitB2 delivery systems. Their physicochemical properties are characterized by DLS, SEM, XRD, FTIR, and TGA-DSC. The release kinetics of VitB2 or Se from the samples are investigated in PBS solution (pH = 2.0, 5.0, 7.4, 8.0 and 12.0). The cytocompatibilities are also evaluated with normal BMSC and epidermal HaCat cells. Results exhibit that Se-PCL@VitB2 particles presents spherical polyhedral morphology (approximately (3.25 ± 0.46) μm), negative surface charge (-(54.03 ± 2.94) mV), reduced crystallinity and good degradability. Stability experiments imply that both VitB2 and Se might be uniformly dispersed in PCL matrix. And the incorporation of Se facilely promotes the loading of VitB2. The encapsulation efficiency and loading capacity are (98.42 ± 1.06)% and (76.25 ± 1.27) for Se-PCL@VitB2 sample. Importantly, it exhibits more prolonged release of both VitB2 and Se in neutral PBS solution (pH = 7.4) than other pH conditions. Presumably, the electrostatic interaction between Se, VitB2 and PCL contribute to its release mode. Cell experiments show that Se-PCL@VitB2 presents strong cytotoxicity to HaCat cells mainly due to the cytotoxic effect of Se anions and PCL degradation products. However, it exhibits weak inhibitory effect on BMSC cells. These note that the synthesized Se-PCL@VitB2 particles can be promising drug vehicles for potential application in epidermal proliferative disorders.

GSH-responsive bithiophene Aza-BODIPY@HMON nanoplatform for achieving triple-synergistic photoimmunotherapy

Photoimmunotherapy represents an innovative approach to enhancing the efficiency of immunotherapy in cancer treatment. This approach involves the fusion of immunotherapy and phototherapy (encompassing techniques like photodynamic therapy (PDT) and photothermal therapy (PTT)). Boron-dipyrromethene (BODIPY) has the potential to trigger immunotherapy owing to its excellent PD and PT efficiency. However, the improvements in water solubility, bioavailability, PD/PT combined efficiency, and tumor tissue targeting of BODIPY require introduction of suitable carriers for potential practical application. Herein, a disulfide bond-based hollow mesoporous organosilica (HMON) with excellent biocompatibility and GSH-responsive degradation properties was used as a carrier to load a bithiophene Aza-BODIPY dye (B5), constructing a sample chemotherapy reagent-free B5@HMON nanoplatform achieving triple-synergistic photoimmunotherapy. HMON, involving disulfide bond, is utilized to improve water solubility, tumor tissue targeting, and PD efficiency by depleting GSH and enhancing host-guest interaction between B5 and HMO. The study reveals that HMON's large specific surface area and porous properties significantly enhance the light collection and oxygen adsorption capacity. The HMON's rich mesoporous structure and internal cavity achieved a loading rate of B5 at 11 %. It was found that the triple-synergistic nanoplatform triggered a stronger anti-tumor immune response, including tumor invasion, cytokine production, calreticulin translocation, and dendritic cell maturation, eliciting specific tumor-specific immunological responses in vivo and in vitro. The BALB/c mouse model with 4T1 tumors was used to assess tumor suppression efficiency in vivo, showing that almost all tumors in the B5@HMON group disappeared after 14 days. Such a simple chemotherapy reagent-free B5@HMON nanoplatform achieved triple-synergistic photoimmunotherapy.

Metal ion interference therapy: metal-based nanomaterial-mediated mechanisms and strategies to boost intracellular "ion overload" for cancer treatment

Metal ion interference therapy (MIIT) has emerged as a promising approach in the field of nanomedicine for combatting cancer. With advancements in nanotechnology and tumor targeting-related strategies, sophisticated nanoplatforms have emerged to facilitate efficient MIIT in xenografted mouse models. However, the diverse range of metal ions and the intricacies of cellular metabolism have presented challenges in fully understanding this therapeutic approach, thereby impeding its progress. Thus, to address these issues, various amplification strategies focusing on ionic homeostasis and cancer cell metabolism have been devised to enhance MIIT efficacy. In this review, the remarkable progress in Fe, Cu, Ca, and Zn ion interference nanomedicines and understanding their intrinsic mechanism is summarized with particular emphasis on the types of amplification strategies employed to strengthen MIIT. The aim is to inspire an in-depth understanding of MIIT and provide guidance and ideas for the construction of more powerful nanoplatforms. Finally, the related challenges and prospects of this emerging treatment are discussed to pave the way for the next generation of cancer treatments and achieve the desired efficacy in patients.

Ferrocene-Conjugated Paclitaxel Prodrug for Combined Chemo-Ferroptosis Therapy of Cancer

Herein, we developed a paclitaxel prodrug (PSFc) through the conjugation of paclitaxel (PTX) and ferrocene via a redox-responsive disulfide bond. PSFc displays acid-enhanced catalytic activity of Fenton reaction and is capable of forming stable nanoparticles (PSFc NPs) through the assembly with distearoyl phosphoethanolamine-PEG2000. After being endocytosed, PSFc NPs could release PTX to promote cell apoptosis in response to overexpressed redox-active species of tumor cells. Meanwhile, the ferrocene-mediated Fenton reaction promotes intracellular accumulation of hydroxyl radicals and depletion of glutathione, thus leading to ferroptosis. Compared with the clinically used Taxol, PSFc NPs exhibited more potent in vivo antitumor outcomes through the combined effect of chemotherapy and ferroptosis. This study may offer insight into a facile design of a prodrug integrating different tumor treatment methods for combating malignant tumors.

Stimuli-Responsive Polymers at the Interface with Biology

There has been growing interest in polymeric systems that break down or undergo property changes in response to stimuli. Such polymers can play important roles in biological systems, where they can be used to control the release of therapeutics, modulate imaging signals, actuate movement, or direct the growth of cells. In this Perspective, after discussing the most important stimuli relevant to biological applications, we will present a selection of recent exciting developments. The growing importance of stimuli-responsive polysaccharides will be discussed, followed by a variety of stimuli-responsive polymeric systems for the delivery of small molecule drugs and nucleic acids. Switchable polymers for the emerging area of therapeutic response measurement in theranostics will be described. Then, the diverse functions that can be achieved using hydrogels cross-linked covalently, as well as by various dynamic approaches will be presented. Finally, we will discuss some of the challenges and future perspectives for the field.

Unveiling Green Synthesis and Biomedical Theranostic paradigms of Selenium Nanoparticles (SeNPs) - A state-of-the-art comprehensive update

The advancements in nanotechnology, pharmaceutical sciences, and healthcare are propelling the field of theranostics, which combines therapy and diagnostics, to new heights; emphasizing the emergence of selenium nanoparticles (SeNPs) as versatile theranostic agents. This comprehensive update offers a holistic perspective on recent developments in the synthesis and theranostic applications of SeNPs, underscoring their growing importance in nanotechnology and healthcare. SeNPs have shown significant potential in multiple domains, including antioxidant, anti-inflammatory, anticancer, antimicrobial, antidiabetic, wound healing, and cytoprotective therapies. The review highlights the adaptability and biocompatibility of SeNPs, which are crucial for advanced disease detection, monitoring, and personalized treatment. Special emphasis is placed on advancements in green synthesis techniques, underscoring their eco-friendly and cost-effective benefits in biosensing, diagnostics, imaging and therapeutic applications. Additionally, the appraisal scrutinizes the progressive trends in smart stimuli-responsive SeNPs, conferring their role in innovative solutions for disease management and diagnostics. Despite their promising therapeutic and prophylactic potential, SeNPs also present several challenges, particularly regarding toxicity concerns. These challenges and their implications for clinical translation are thoroughly explored, providing a balanced view of the current state and prospects of SeNPs in theranostic applications.

Remodeling the hepatic immune microenvironment and demolishing T cell traps to enhance immunotherapy efficacy in liver metastasis

Immune checkpoint inhibitors (ICIs) exhibit compromised therapeutic efficacy in many patients with advanced cancers, particularly those with liver metastases. Much of this incapability can be ascribed as an irresponsiveness resulting from the "cold" hepatic tumor microenvironment that acts as T cell "traps" for which there currently lack countermeasures. We report a novel nanomedicine that converts the hepatic immune microenvironment to a "hot" phenotype by targeting hepatic macrophage-centric T cell elimination. Using the nanomedicine, composed of KIRA6 (an endothelium reticulum stress inhibitor), α-Tocopherol nanoemulsions, and anti-PD1 antibodies, we found its potency in murine models of orthotopic colorectal tumors and hepatic metastases, restoring immune responses and enhancing anti-tumor effects. A post-treatment scrutiny of the immune microenvironment landscape in the liver reveals repolarization of immunosuppressive hepatic macrophages, upregulation of Th1-like effector CD4+ T cells, and rejuvenation of dendritic cells along with CD8+ T cells. These findings suggest adaptations of liver-centric immune milieu modulation strategies to improve the efficacy of ICIs for a variety of "cold" tumors and their liver metastases.

Nanomaterials in Immunology: Bridging Innovative Approaches in Immune Modulation, Diagnostics, and Therapy

The intersection of immunology and nanotechnology has provided significant advancements in biomedical research and clinical applications over the years. Immunology aims to understand the immune system's defense mechanisms against pathogens. Nanotechnology has demonstrated its potential to manipulate immune responses, as nanomaterials' properties can be modified for the desired application. Research has shown that nanomaterials can be applied in diagnostics, therapy, and vaccine development. In diagnostics, nanomaterials can be used for biosensor development, accurately detecting biomarkers even at very low concentrations. Therapeutically, nanomaterials can act as efficient carriers for delivering drugs, antigens, or genetic material directly to targeted cells or tissues. This targeted delivery improves therapeutic efficacy and reduces the adverse effects on healthy cells and tissues. In vaccine development, nanoparticles can improve vaccine durability and extend immune responses by effectively delivering adjuvants and antigens to immune cells. Despite these advancements, challenges regarding the safety, biocompatibility, and scalability of nanomaterials for clinical applications are still present. This review will cover the fundamental interactions between nanomaterials and the immune system, their potential applications in immunology, and their safety and biocompatibility concerns.

Selenium-Doped Nanoheterojunctions for Highly Efficient Cancer Radiosensitization

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

Custom-Design of Multi-Stimuli-Responsive Degradable Silica Nanoparticles for Advanced Cancer-Specific Chemotherapy

Chemotherapy is crucial in oncology for combating malignant tumors but often encounters obatacles such as severe adverse effects, drug resistance, and biocompatibility issues. The advantages of degradable silica nanoparticles in tumor diagnosis and treatment lie in their ability to target drug delivery, minimizing toxicity to normal tissues while enhancing therapeutic efficacy. Moreover, their responsiveness to both endogenous and exogenous stimuli opens up new possibilities for integrating multiple treatment modalities. This review scrutinizes the burgeoning utility of degradable silica nanoparticles in combination with chemotherapy and other treatment modalities. Commencing the elucidation of degradable silica synthesis and degradation mechanisms, emphasis is placed on the responsiveness of these materials to endogenous (e.g., pH, redox reactions, hypoxia, and enzymes) and exogenous stimuli (e.g., light and high-intensity focused ultrasound). Moreover, this exploration delves into strategies harnessing degradable silica nanoparticles in chemotherapy alone, coupled with radiotherapy, photothermal therapy, photodynamic therapy, gas therapy, immunotherapy, starvation therapy, and chemodynamic therapy, elucidating multimodal synergies. Concluding with an assessment of advances, challenges, and constraints in oncology, despite hurdles, future investigations are anticipated to augment the role of degradable silica in cancer therapy. These insights can serve as a compass for devising more efficacious combined tumor treatment strategies.

Natural Killer-Based Therapy: A Prospective Thought for Cancer Treatment Related to Diversified Drug Delivery Pathways

Immunotherapy has been a research hotspot due to its low side effects, long-lasting efficacy, and wide anti-tumor spectrum. Recently, NK cell-based immunotherapy has gained broad attention for its unique immunological character of tumor identification and eradication and low risk of graft-versus-host disease and cytokine storm. With the cooperation of a drug delivery system (DDS), NK cells activate tumoricidal activity by adjusting the balance of the activating and inhibitory signals on their surface after drug-loaded DDS administration. Moreover, NK cells or NK-derived exosomes can also be applied as drug carriers for distinct modification to promote NK activation and exert anti-tumor effects. In this review, we first introduce the source and classification of NK cells and describe the common activating and inhibitory receptors on their surface. Then, we summarize the strategies for activating NK cells in vivo through various DDSs. Finally, the application prospects of NK cells in tumor immunotherapy are also discussed.

Radioactive hybrid semiconducting polymer nanoparticles for imaging-guided tri-modal therapy of breast cancer

Due to the rapid progression and aggressive metastasis of breast cancer, its diagnosis and treatment remain a great challenge. The simultaneous inhibition of tumor growth and metastasis is necessary for breast cancer to obtain ideal therapeutic outcomes. We herein report the development of radioactive hybrid semiconducting polymer nanoparticles (SPNH) for imaging-guided tri-modal therapy of breast cancer. Two semiconducting polymers are used to form SPNH with a diameter of around 60 nm via nano-coprecipitation and they are also labeled with iodine-131 (131I) to enhance the imaging functions. The formed SPNH show good radiolabeling stability and excellent photodynamic and photothermal effects under 808 nm laser irradiation to produce singlet oxygen (1O2) and heat. Moreover, SPNH can generate 1O2 with ultrasound irradiation via their sonodynamic properties. After intravenous tail vein injection, SPNH can effectively accumulate in the subcutaneous 4T1 tumors of living mice as verified via fluorescence and single photon emission computed tomography (SPECT) imaging. With the irradiation of tumors using an 808 nm laser and US, SPNH mediate photodynamic therapy (PDT), photothermal therapy (PTT) and sonodynamic therapy (SDT) to kill tumor cells. Such a tri-modal therapy leads to an improved efficacy in inhibiting tumor growth and suppressing tumor metastasis compared to the sole SDT and combinational PDT-PTT. This study thus demonstrates the applications of SPNH to diagnose tumors and combine different therapies for effective breast cancer treatment.

Immunological nanomaterials to combat cancer metastasis

Metastasis causes greater than 90% of cancer-associated deaths, presenting huge challenges for detection and efficient treatment of cancer due to its high heterogeneity and widespread dissemination to various organs. Therefore, it is imperative to combat cancer metastasis, which is the key to achieving complete cancer eradication. Immunotherapy as a systemic approach has shown promising potential to combat metastasis. However, current clinical immunotherapies are not effective for all patients or all types of cancer metastases owing to insufficient immune responses. In recent years, immunological nanomaterials with intrinsic immunogenicity or immunomodulatory agents with efficient loading have been shown to enhance immune responses to eliminate metastasis. In this review, we would like to summarize various types of immunological nanomaterials against metastasis. Moreover, this review will summarize a series of immunological nanomaterial-mediated immunotherapy strategies to combat metastasis, including immunogenic cell death, regulation of chemokines and cytokines, improving the immunosuppressive tumour microenvironment, activation of the STING pathway, enhancing cytotoxic natural killer cell activity, enhancing antigen presentation of dendritic cells, and enhancing chimeric antigen receptor T cell therapy. Furthermore, the synergistic anti-metastasis strategies based on the combinational use of immunotherapy and other therapeutic modalities will also be introduced. In addition, the nanomaterial-mediated imaging techniques (e.g., optical imaging, magnetic resonance imaging, computed tomography, photoacoustic imaging, surface-enhanced Raman scattering, radionuclide imaging, etc.) for detecting metastasis and monitoring anti-metastasis efficacy are also summarized. Finally, the current challenges and future prospects of immunological nanomaterial-based anti-metastasis are also elucidated with the intention to accelerate its clinical translation.

Programmable melanoma-targeted radio-immunotherapy via fusogenic liposomes functionalized with multivariate-gated aptamer assemblies

Radio-immunotherapy exploits the immunostimulatory features of ionizing radiation (IR) to enhance antitumor effects and offers emerging opportunities for treating invasive tumor indications such as melanoma. However, insufficient dose deposition and immunosuppressive microenvironment (TME) of solid tumors limit its efficacy. Here we report a programmable sequential therapeutic strategy based on multifunctional fusogenic liposomes (Lip@AUR-ACP-aptPD-L1) to overcome the intrinsic radio-immunotherapeutic resistance of solid tumors. Specifically, fusogenic liposomes are loaded with gold-containing Auranofin (AUR) and inserted with multivariate-gated aptamer assemblies (ACP) and PD-L1 aptamers in the lipid membrane, potentiating melanoma-targeted AUR delivery while transferring ACP onto cell surface through selective membrane fusion. AUR amplifies IR-induced immunogenic death of melanoma cells to release antigens and damage-associated molecular patterns such as adenosine triphosphate (ATP) for triggering adaptive antitumor immunity. AUR-sensitized radiotherapy also upregulates matrix metalloproteinase-2 (MMP-2) expression that combined with released ATP to activate ACP through an "and" logic operation-like process (AND-gate), thus triggering the in-situ release of engineered cytosine-phosphate-guanine aptamer-based immunoadjuvants (eCpG) for stimulating dendritic cell-mediated T cell priming. Furthermore, AUR inhibits tumor-intrinsic vascular endothelial growth factor signaling to suppress infiltration of immunosuppressive cells for fostering an anti-tumorigenic TME. This study offers an approach for solid tumor treatment in the clinics.

Differential reinforcement of cGAS-STING pathway-involved immunotherapy by biomineralized bacterial outer membrane-sensitized EBRT and RNT

Radiotherapy (RT), including external beam radiation therapy (EBRT) and radionuclide therapy (RNT), realizes physical killing of local tumors and activates systemic anti-tumor immunity. However, these effects need to be further strengthened and the difference between EBRT and RNT should be discovered. Herein, bacterial outer membrane (OM) was biomineralized with manganese oxide (MnO2) to obtain OM@MnO2-PEG nanoparticles for enhanced radio-immunotherapy via amplifying EBRT/RNT-induced immunogenic cell death (ICD) and cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) activation. OM@MnO2-PEG can react with H2O2 and then gradually produce O2, Mn2+ and OM fragments in the tumor microenvironment. The relieved tumor hypoxia improves the radio-sensitivity of tumor cells, resulting in enhanced ICD and DNA damage. Mn2+ together with the DNA fragments in the cytoplasm activate the cGAS-STING pathway, further exhibiting a positive role in various aspects of innate immunity and adaptive immunity. Besides, OM fragments promote tumor antigen presentation and anti-tumor macrophages polarization. More importantly, our study reveals that OM@MnO2-PEG-mediated RNT triggers much stronger cGAS-STING pathway-involved immunotherapy than that of EBRT, owing to the duration difference of RT. Therefore, this study develops a powerful sensitizer of radio-immunotherapy and uncovers some differences between EBRT and RNT in the activation of cGAS-STING pathway-related anti-tumor immunity.

Long-term relapse-free survival enabled by integrating targeted antibacteria in antitumor treatment

The role of tumor-resident intracellular microbiota (TRIM) in carcinogenesis has sparked enormous interest. Nevertheless, the impact of TRIM-targeted antibacteria on tumor inhibition and immune regulation in the tumor microenvironment (TME) remains unexplored. Herein, we report long-term relapse-free survival by coordinating antibacteria with antitumor treatment, addressing the aggravated immunosuppression and tumor overgrowth induced by TRIM using breast and prostate cancer models. Combining Ag+ release with a Fenton-like reaction and photothermal conversion, simultaneous bacteria killing and multimodal antitumor therapy are enabled by a single agent. Free of immune-stimulating drugs, the agent restores antitumor immune surveillance and activates immunological responses. Secondary inoculation and distal tumor analysis confirm lasting immunological memory and systemic immune responses. A relapse-free survival of >700 days is achieved. This work unravels the crucial role of TRIM-targeted antibacteria in tumor inhibition and unlocks an unconventional route for immune regulation in TME and a complete cure for cancer.

Selenium-Containing Nanocomplexes Achieve Dual Immune Checkpoint Blockade for NK Cell Reinvigoration

The blockade of immune checkpoints has emerged as a promising strategy for cancer immunotherapy. However, most of the current approaches focus on T cells, leaving natural killer (NK) cell-mediated therapeutic strategies rarely explored. Here, a selenium-containing nanocomplex is developed that acts as a dual immune checkpoint inhibitor to reinvigorate NK cell-based cancer immunotherapy. The Se nanocomplex can deliver and release siRNA that targets programmed death ligand-1 (PD-L1) in tumor cells, thereby silencing the checkpoint receptor PD-L1. The intracellular reactive oxygen species generated by porphyrin derivatives in the nanocomplexes can oxidize the diselenide bond into seleninic acid, which blocks the expression of another checkpoint receptor, human leukocyte antigen E. The blockade of dual immune checkpoints shows synergistic effects on promoting NK cell-mediated antitumoral activity. This study provides a new strategy to reinvigorate NK cell immunity for the development of combined cancer immunotherapy.

Therapeutic Applications of Nanomedicine: Recent Developments and Future Perspectives

The concept of nanomedicine has evolved significantly in recent decades, leveraging the unique phenomenon known as the enhanced permeability and retention (EPR) effect. This has facilitated major advancements in targeted drug delivery, imaging, and individualized therapy through the integration of nanotechnology principles into medicine. Numerous nanomedicines have been developed and applied for disease treatment, with a particular focus on cancer therapy. Recently, nanomedicine has been utilized in various advanced fields, including diagnosis, vaccines, immunotherapy, gene delivery, and tissue engineering. Multifunctional nanomedicines facilitate concurrent medication delivery, therapeutic monitoring, and imaging, allowing for immediate responses and personalized treatment plans. This review concerns the major advancement of nanomaterials and their potential applications in the biological and medical fields. Along with this, we also mention the various clinical translations of nanomedicine and the major challenges that nanomedicine is currently facing to overcome the clinical translation barrier.

Biogenic crocetin-crosslinked chitosan nanoparticles with high stability and drug loading for efficient radioprotection

The risk of radiation exposure increases with the development of nuclear energy and technology, and radiation protection receives more and more attention from public health and safety. However, the numerous adverse effects and low drug utilization limit the practical applications of radioprotective agents. In this study, we developed a biogenic crocetin-crosslinked chitosan nanoparticle with high stability and drug loading for efficient radioprotection. In detail, the nanoparticles were prepared using the natural antioxidant crocetin as a cross-linking reagent in amidation reactions of chitosan and mPEG-COOH. The nanoparticles exhibit a quick scavenging ability for common reactive oxygen species and reactive nitrogen in vitro. Meanwhile, cellular experiments demonstrate the good biocompatibility of the nanoparticles and the alleviation of radiation damage by scavenging reactive oxygen species, reducing apoptosis, and inhibiting DNA damage, etc. Importantly, the nanoparticles are effective in mitigating oxidative damage in major organs and maintaining peripheral blood cell content. In addition, they perform better radioprotective properties than free drug due to the significant extension of the blood half-life of crocetin in vivo from 10 min to 5 h. This work proposes a drug-crosslinking strategy for the design of a highly efficient radioprotective agent, which exhibits a promising prospect in the fields of nuclear emergency and public health.

Nanocatalytic Anti-Tumor Immune Regulation

Immunotherapy has brought a new dawn for human being to defeat cancer. Although existing immunotherapy regimens (CAR-T, etc.) have made breakthroughs in the treatments of hematological cancer and few solid tumors such as melanoma, the therapeutic efficacy on most solid tumors is still far from being satisfactory. In recent years, the researches on tumor immunotherapy based on nanocatalytic materials are under rapid development, and significant progresses have been made. Nanocatalytic medicine has been demonstrated to be capable of overcoming the limitations of current clinicnal treatments by using toxic chemodrugs, and exhibits highly attractive advantages over traditional therapies, such as the enhanced and sustained therapeutic efficacy based on the durable catalytic activity, remarkably reduced harmful side-effects without using traditional toxic chemodrugs, and so on. Most recently, nanocatalytic medicine has been introduced in the immune-regulation for disease treatments, especially, in the immunoactivation for tumor therapies. This article presents the most recent progresses in immune-response activations by nanocatalytic medicine-initiated chemical reactions for tumor immunotherapy, and elucidates the mechanism of nanocatalytic medicines in regulating anti-tumor immunity. By reviewing the current research progress in the emerging field, this review will further highlight the great potential and broad prospects of nanocatalysis-based anti-tumor immune-therapeutics.

Rejuvenating Aged Bone Repair through Multihierarchy Reactive Oxygen Species-Regulated Hydrogel

Aging exacerbates the dysfunction of tissue regeneration at multiple levels and gradually diminishes individual's capacity to withstand stress, damage, and disease. The excessive accumulation of reactive oxygen species (ROS) is considered a hallmark feature of senescent stem cells, which causes oxidative stress, deteriorates the host microenvironment, and eventually becomes a critical obstacle for aged bone defect repair. Till now, the strategies cannot synchronously and thoroughly regulate intracellular and extracellular ROS in senescent cells. Herein, a multihierarchy ROS scavenging system for aged bone regeneration is developed by fabricating an injectable PEGylated poly(glycerol sebacate) (PEGS-NH2 )/poly(γ-glutamic acid) (γ-PGA) hydrogel containing rapamycin-loaded poly(diselenide-carbonate) nanomicelles (PSeR). This PSeR hydrogel exhibits highly sensitive ROS responsiveness to the local aged microenvironment and dynamically releases drug-loaded nanomicelles to scavenge the intracellular ROS accumulated in senescent bone mesenchymal stem cells. The PSeR hydrogel effectively tunes the antioxidant function and delays senescence of bone mesenchymal stem cells by safeguarding DNA replication in an oxidative environment, thereby promoting the self-renewal ability and enhancing the osteogenic capacity for aged bone repair in vitro and in vivo. Thus, this multihierarchy ROS-regulated hydrogel provides a new strategy for treating degenerative diseases.

Research Progress of Nanomaterials Acting on NK Cells in Tumor Immunotherapy and Imaging

The prognosis for cancer patients has declined dramatically in recent years due to the challenges in treating malignant tumors. Tumor immunotherapy, which includes immune target inhibition and chimeric antigen receptor cell treatment, is currently evolving quickly. Among them, natural killer (NK) cells are gradually becoming another preferred cell immunotherapy after T cell immunotherapy due to their unique killing effects in innate and adaptive immunity. NK cell therapy has shown encouraging outcomes in clinical studies; however, there are still some problems, including limited efficacy in solid tumors, inadequate NK cell penetration, and expensive treatment expenses. Noteworthy benefits of nanomaterials include their chemical specificity, biocompatibility, and ease of manufacturing; these make them promising instruments for enhancing NK cell anti-tumor immune responses. Nanomaterials can promote NK cell homing and infiltration, participate in NK cell modification and non-invasive cell tracking and imaging modes, and greatly increase the effectiveness of NK cell immunotherapy. The introduction of NK cell-based immunotherapy research and a more detailed discussion of nanomaterial research in NK cell-based immunotherapy and molecular imaging will be the main topics of this review.

Ultrathin 2D As2Se3 Nanosheets for Photothermal-Triggered Cancer Immunotherapy

Arsenic trioxide (As2O3) has achieved groundbreaking success in the treatment of acute promyelocytic leukemia (APL). However, its toxic side effects seriously limit its therapeutic application in the treatment of solid tumors. To detoxify the severe side effects of arsenic, herein we synthesized innovative 2D ultrathin As2Se3 nanosheets (As2Se3 NSs) with synergistic photothermal-triggered immunotherapy effects. As2Se3 NSs are biocompatible and biodegradable under physiological conditions and can release As(III) and Se(0). Furthermore, selenium increases the immunomodulatory efficacy of arsenic treatments, facilitating reprogramming of the tumor microenvironment by As2Se3 NSs by enhancing the infiltration of natural killer cells and effector tumor-specific CD8+ T cells. The synergistic combination of photothermal therapy and immunotherapy driven by As2Se3 NSs via a simple but effective all-in-one strategy achieved efficient anticancer effects, addressing the key limitations of As2O3 for solid tumor treatment. This work demonstrates not only the great potential of selenium for detoxifying arsenic but also the application of 2D As2Se3 nanosheets for cancer therapy.

Stimuli-responsive biodegradable silica nanoparticles: From native structure designs to biological applications

Due to their inherent advantages, silica nanoparticles (SiNPs) have greatly potential applications as bioactive materials in biosensors/biomedicine. However, the long-term and nonspecific accumulation in healthy tissues may give rise to toxicity, thereby impeding their widespread clinical application. Hence, it is imperative and noteworthy to develop biodegradable and clearable SiNPs for biomedical purposes. Recently, the design of multi-stimuli responsive SiNPs to improve degradation efficiency under specific pathological conditions has increased their clinical trial potential as theranostic nanoplatform. This review comprehensively summaries the rational design and recent progress of biodegradable SiNPs under various internal and external stimuli for rapid in vivo degradation and clearance. In addition, the factors that affect the biodegradation of SiNPs are also discussed. We believe that this systematic review will offer profound stimulus and timely guide for further research in the field of SiNP-based nanosensors/nanomedicine.

Glucose oxidase and ruthenium nanorods-embedded self-healing polyvinyl alcohol/polyethylene imine hydrogel for simultaneous photothermal/photodynamic/starvation therapy and skin reconstruction

Tumor recurrence and wound healing represent significant burdens for tumor patients after the surgical removal of melanomas. Wound dressings with wound healing and anticancer therapeutic abilities could help to solve these issues. Thus, a hybrid hydrogel made of polyvinyl alcohol (PVA) and polyethylene imine (PEI) was prepared by cross-linking imine bond and boronic acid bond. This hydrogel was loaded with ruthenium nanorods (Ru NRs) and glucose oxidase (GOx) and named as nanocomposite hydrogel (Ru/GOx@Hydrogel), exhibiting remarkable photothermal/photodynamic/starvation antitumor therapy and wound repair abilities. Ru NRs are bifunctional phototherapeutic agents that simultaneously exhibit intrinsic photothermal and photodynamic functions. Three-dimensional composite hydrogel loaded with GOx can also consume glucose in the presence of O2 during tumor starvation therapy. Near-infrared (NIR) light-triggered hyperthermia can not only promote the consumption of glucose, but also facilitate the ablation of residual cancer cells. The antitumor effect of the Ru/GOx@Hydrogel resulted in significant improvements, compared to those observed with either phototherapy or starvation therapy alone. Additionally, the postoperative wound was substantially healed after treatment with Ru/GOx@Hydrogel and NIR irradiation. Therefore, the Ru/GOx@Hydrogel can be used as a multi-stimulus-responsive nanoplatform that could facilitate on-demand controlled drug release, and be used as a promising postoperative adjuvant in combination therapy.

Radioresponsive Delivery of Toll-like Receptor 7/8 Agonist for Tumor Radioimmunotherapy Enabled by Core-Cross-Linked Diselenide Nanoparticles

The development of a radioresponsive delivery platform has led to an innovative combination radioimmunotherapy strategy for treating tumors. However, controlling the release of immunomodulators by local radiotherapy in vivo remains a significant challenge in order to minimize off-target toxicity, reduce radiation-induced immunosuppression, and maximize synergistic radioimmunotherapy efficacy. In this study, we report the development of core-cross-linked diselenide nanoparticles (dSeNPs) as carriers for radioresponsive delivery of the toll-like receptors 7/8 agonist through systemic administration to achieve combined radioimmunotherapy of tumors. The dSeNPs were fabricated from a ring-opening reaction between 2,2'-diselenidebis(ethylamine) and the ethylene oxide group of an amphiphilic block copolymer. The diselenide bonds were naturally protected in the core of the self-assembled nanostructure, making the dSeNPs extremely stable in the physiological environment. However, they exhibited dose- and time-dependent radiosensitivity, meaning that X-ray irradiation could spatiotemporally control the release of R848 from the dSeNPs. In vivo results showed that local radioresponsive R848 release from dSeNPs greatly improved the synergistic efficacy of combined radioimmunotherapy via the programmed cooperative immune system activation process. This process included macrophage polarization, dendritic cell maturation, and cytotoxic T cell activation. Our findings suggest that core-cross-linked dSeNPs are a promising platform for combined radiotherapy due to their spatiotemporal controllability of radioresponsive drug release.

Radioprotective Effect of Selenium Nanoparticles: A Mini Review

Materials and Methods

This study followed the PRISMA reporting guidelines to present the results. A comprehensive search was performed on electronic databases such as PubMed, Scopus, Web of Sciences, and Science Direct. Initially, 413 articles were retrieved. After removing duplicates and applying specific inclusion and exclusion criteria, 10 articles were finally included in this systematic review.

Results

The reviewed studies showed that selenium nanoparticles had anti-inflammatory and antioxidant properties. They effectively protected the kidneys, liver, and testicles from damage. Furthermore, there was evidence of efficient radioprotection for the organs examined without significant side effects.

Conclusions

This systematic review emphasizes the potential advantages of using selenium nanoparticles to prevent the negative effects of ionizing radiation. Importantly, these protective effects were achieved without causing noticeable side effects. These findings suggest the potential role of selenium nanoparticles as radioprotective agents, offering possible therapeutic applications to reduce the risks related to ionizing radiation exposure in medical imaging and radiotherapy procedures.

Cleavage and Noncleavage Chemistry in Reactive Oxygen Species (ROS)-Responsive Materials for Smart Drug Delivery

The design and development of advanced drug delivery systems targeting reactive oxygen species (ROS) have gained significant interest in recent years for treating various diseases, including cancer, psychiatric diseases, cardiovascular diseases, neurological diseases, metabolic diseases, and chronic inflammations. Integrating specific chemical bonds capable of effectively responding to ROS and triggering drug release into the delivery system is crucial. In this Review, we discuss commonly used conjugation linkers (chemical bonds) and categorize them into two groups: cleavable linkers and noncleavable linkers. Our goal is to clarify their unique drug release mechanisms from a chemical perspective and provide practical organic synthesis approaches for their efficient production. We showcase numerous significant examples to demonstrate their synthesis routes and diverse applications. Ultimately, we strive to present a comprehensive overview of cleavage and noncleavage chemistry, offering insights into the development of smart drug delivery systems that respond to ROS.

The progression of inorganic nanoparticles and natural products for inflammatory bowel disease

There is a growing body of evidence indicating a close association between inflammatory bowel disease (IBD) and disrupted intestinal homeostasis. Excessive production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), along with an increase in M1 proinflammatory macrophage infiltration during the activation of intestinal inflammation, plays a pivotal role in disrupting intestinal homeostasis in IBD. The overabundance of ROS/RNS can cause intestinal tissue damage and the disruption of crucial gut proteins, which ultimately compromises the integrity of the intestinal barrier. The proliferation of M1 macrophages contributes to an exaggerated immune response, further compromising the intestinal immune barrier. Currently, intestinal nanomaterials have gained widespread attention in the context of IBD due to their notable characteristics, including the ability to specifically target regions of interest, clear excess ROS/RNS, and mimic biological enzymes. In this review, we initially elucidated the gut microenvironment in IBD. Subsequently, we delineate therapeutic strategies involving two distinct types of nanomedicine, namely inorganic nanoparticles and natural product nanomaterials. Finally, we present a comprehensive overview of the promising prospects associated with the application of nanomedicine in future clinical settings for the treatment of IBD (graphic abstract). Different classes of nanomedicine are used to treat IBD. This review primarily elucidates the current etiology of inflammatory bowel disease and explores two prominent nanomaterial-based therapeutic approaches. First, it aims to eliminate excessive reactive oxygen species and reactive nitrogen species. Second, they focus on modulating the polarization of inflammatory macrophages and reducing the proportion of pro-inflammatory macrophages. Additionally, this article delves into the treatment of inflammatory bowel disease using inorganic metal nanomaterials and natural product nanomaterials.

Harnessing astaxanthin-loaded diselenium cross-linked apotransferrin nanoparticles for the treatment of secretory otitis media

Secretory otitis media (SOM) is a clinical condition characterized by the accumulation of fluids and oxidative stress in the middle ear, leading to hearing impairment and infection complications. One potential solution for mitigating oxidative stress associated with SOM is the use of antioxidants such as astaxanthin. However, its effectiveness is limited due to its poor bioavailability and rapid oxidation. Herein, we developed a novel diselenium-crosslinked apotransferrin enriched with astaxanthin (AST@dSe-AFT) nanoparticles to augment the transport of astaxanthin across biological membranes, resulting in increased bioavailability and reduced oxidative stress in SOM. Our research demonstrated that AST@dSe-AFT efficiently accumulated in the middle ear, allowing for controlled delivery of astaxanthin in response to reactive oxygen species and reducing oxidative stress. Additionally, AST@dSe-AFT stimulated macrophages to polarize towards M2 phenotype and neutrophils to polarize towards N2 phenotype, thereby facilitating an anti-inflammatory response and tissue restoration. Importantly, AST@dSe-AFT exhibited no toxicity or adverse effects, suggesting its potential for safety and future clinical translation. Our findings suggested that AST@dSe-AFT represents a promising approach for the treatment of secretory otitis media and other oxidative stress-related disorders.

NK cell-based tumor immunotherapy

Natural killer (NK) cells display a unique inherent ability to identify and eliminate virus-infected cells and tumor cells. They are particularly powerful for elimination of hematological cancers, and have attracted considerable interests for therapy of solid tumors. However, the treatment of solid tumors with NK cells are less effective, which can be attributed to the very complicated immunosuppressive microenvironment that may lead to the inactivation, insufficient expansion, short life, and the poor tumor infiltration of NK cells. Fortunately, the development of advanced nanotechnology has provided potential solutions to these issues, and could improve the immunotherapy efficacy of NK cells. In this review, we summarize the activation and inhibition mechanisms of NK cells in solid tumors, and the recent advances in NK cell-based tumor immunotherapy boosted by diverse nanomaterials. We also propose the challenges and opportunities for the clinical application of NK cell-based tumor immunotherapy.