Free radicals for cancer theranostics

Current role of magnetic resonance imaging on assessing and monitoring the efficacy of phototherapy

Phototherapy, also known as photobiological therapy, is a non-invasive and highly effective physical treatment method. Its broad use in clinics has led to significant therapeutic results. Phototherapy parameters, such as intensity, wavelength, and duration, can be adjusted to create specific therapeutic effects for various medical conditions. Meanwhile, Magnetic Resonance Imaging (MRI), with its diverse imaging sequences and excellent soft-tissue contrast, provides a valuable tool to understand the therapeutic effects and mechanisms of phototherapy. This review explores the clinical applications of commonly used phototherapy techniques, gives a brief overview of how phototherapy impacts different diseases, and examines MRI's role in various phototherapeutic scenarios. We argue that MRI is crucial for precise targeting, treatment monitoring, and prognosis assessment in phototherapy. Future research and applications will focus on personalized diagnosis and monitoring of phototherapy, expanding its applications in treatment and exploring multimodal imaging technology to enhance diagnostic and therapeutic precision and effectiveness.

Self-Regenerating Photothermal Agents for Tandem Photothermal and Thermodynamic Tumor Therapy

Small molecule-based photothermal agents (PTAs) hold promising future for photothermal therapy; however, unexpected inactivation exerts negative impacts on their application clinically. Herein, a self-regenerating PTA strategy is proposed by integrating 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•+) with a thermodynamic agent (TDA) 2,2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH). Under NIR laser, the photothermal effect of ABTS•+ accelerates the production of alkyl radicals by AIPH, which activates the regeneration of ABTS•+, thus creating a continuous positive feedback loop between photothermal and thermodynamic effects. The combination of ABTS•+ regeneration and alkyl radical production leads to the tandem photothermal and thermodynamic tumor therapy. In vitro and in vivo experiments confirm that the synergistic action of thermal ablation, radical damage, and oxidative stress effectively realizes tumor suppression. This work offers a promising approach to address the unwanted inactivation of PTAs and provides valuable insights for optimizing combination therapy.

Metal-organic frameworks as candidates for tumor sonodynamic therapy: Designable structures for targeted multifunctional transformation

Sonodynamic therapy (SDT), utilizing ultrasound (US) as the trigger, has gained popularity recently as a therapeutic approach with significant potential for treating various diseases. Metal-organic frameworks (MOFs), characterized by structural flexibility, are prominently emerging in the SDT realm as an innovative type of sonosensitizer, offering functional tunability and biocompatibility. However, due to the inherent limitations of MOFs, such as low reactivity to reactive oxygen species and challenges posed by the complex tumor microenvironment, MOF-based sonosensitizers with singular functions are unable to demonstrate the desired therapeutic efficacy and may pose risks of toxicity, limiting their biological applications to superficial tissues. MOFs generally possess distinctive crystalline structures and properties, and their controlled coordination environments provide a flexible platform for exploring structure-effect relationships and guiding the design and development of MOF-based nanomaterials to unlock their broader potential in biological fields. The primary focus of this paper is to summarize cases involving the modification of different MOF materials and the innovative strategies developed for various complex conditions. The paper outlines the diverse application areas of functionalized MOF-based sonosensitizers in tumor synergistic therapies, highlighting the extensive prospects of SDT. Additionally, challenges confronting SDT are briefly summarized to stimulate increased scientific interest in the practical application of MOFs and the successful clinical translation of SDT. Through these discussions, we strive to foster advancements that lead to early-stage clinical benefits for patients. STATEMENT OF SIGNIFICANCE: 1. An overview for the progresses in SDT explored from a novel and fundamental perspective. 2. Different modification strategies to improve the MOFs-mediated SDT efficacy are provided. 3. Guidelines for the design of multifunctional MOFs-based sonosensitizers are offered. 4. Powerful tumor ablation potential is reflected in SDT-led synergistic therapies. 5. Future challenges in the field of MOFs-based SDT in clinical translation are suggested.

Boron Cluster Renders Organic Radicals Water-Stable for Photothermal Anti-Infections

Water-stable organic radicals are promising photothermal conversion candidates for photothermal therapy (PTT). However, organic radicals are usually unstable in biological environments, which greatly hinders their wide application. Here, we have developed a chaotropic effect-based and photoinduced water-stable supramolecular radical (MB12-2) for efficient antibacterial PTT. The supramolecular radical precursor MB12-1 was constructed by the chaotropic effect between closo-dodecaborate cluster (B12H122-) and N,N'-dimethylated dipyridinium thiazolo [5,4-d] thiazole (MPT2+). Subsequently, with triethanolamine (TEOA) serving as an electron donor, MB12-1 could transform to its radical form MB12-2 through photoinduced electron transfer (PET) under 435-nm laser irradiation. The N2 adsorption-desorption analysis confirmed that MB12-2 was tightly packed through the introduction of B12H122-, which effectively enhanced its stability via a spatial site-blocked effect. Moreover, the half-life of MB12-2 in water was calculated through ultraviolet-visible light (UV-vis) absorption spectra results for periods as long as 20 days. In addition, in the skin infection model, MB12-2, as a wound dressing, showed remarkable photothermal antibacterial activity (>97%) under 660-nm laser irradiation and promoted wound healing. This study presents a simple method for designing long-term water-stable supramolecular radicals, offering a novel avenue for noncontact treatments for bacterial infections.

Construction of BaTiO3-TiO2 hollow sphere heterojunctions for enhanced microwave dynamic therapy in cancer treatment

Cancer is one of the primary health concerns among humans due to its high incidence rate and lack of effective treatment. Currently, medical techniques to achieve the precise elimination of local cancer lesions with negligible damage to normal tissues are still intensely desired. Herein, we synthesized BaTiO3-TiO2 hollow spheres (BTHSs) for use in microwave dynamic therapy (MWDT) for cancer. Under UV irradiation, BTHSs can mediate the production of multiple reactive oxygen species (ROS), mainly 1O2, which results in a rapid photocatalytic degradation rate (97%), 1.6-fold that of commercial P25. Importantly, the ROS production process can be triggered by microwaves to effectively execute MWDT for cancer. Under microwave irradiation, BTHSs exhibit a remarkable therapeutic effect and slight cytotoxicity. In terms of mechanism, the enhanced ROS production efficiency of BTHSs can be attributed to their unique hollow structure and the formation of a type-II heterojunction by the incorporation of BaTiO3. The hollow structure increases the availability of active sites and enhances light scattering, while the BaTiO3-TiO2 heterojunction enhances the photocatalytic activity of TiO2 through charge transfer and electron-hole separation. Overall, this study provides important insights into the design and optimization of sensitizers for MWDT applications.

A ROS storm generating nanocomposite for enhanced chemodynamic therapy through H2O2 self-supply, GSH depletion and calcium overload

Catalytic generation of toxic hydroxyl radicals (˙OH) from hydrogen peroxide (H2O2) is an effective strategy for tumor treatment in chemodynamic therapy (CDT). However, the intrinsic features of the microenvironment in solid tumors, characterized by limited H2O2 and overexpressed glutathione (GSH), severely impede the accumulation of intracellular ˙OH, posing significant challenges. To circumvent these critical issues, in this work, a CaO2-based multifunctional nanocomposite with a surface coating of Cu2+ and L-buthionine sulfoximine (BSO) (named CaO2@Cu-BSO) is designed for enhanced CDT. Taking advantage of the weakly acidic environment of the tumor, the nanocomposite gradually disintegrates, and the exposed CaO2 nanoparticles subsequently decompose to produce H2O2, alleviating the insufficient supply of endogenous H2O2 in the tumor microenvironment (TME). Furthermore, Cu2+ detached from the surface of CaO2 is reduced by H2O2 and GSH to Cu+ and ROS. Then, Cu+ catalyzes H2O2 to generate highly cytotoxic ˙OH and Cu2+, forming a cyclic catalysis effect for effective CDT. Meanwhile, GSH is depleted by Cu2+ ions to eliminate possible ˙OH scavenging. In addition, the decomposition of CaO2 by TME releases a large amount of free Ca2+, resulting in the accumulation and overload of Ca2+ and mitochondrial damage in tumor cells, further improving CDT efficacy and accelerating tumor apoptosis. Besides, BSO, a molecular inhibitor, decreases GSH production by blocking γ-glutamyl cysteine synthetase. Together, this strategy allows for enhanced CDT efficiency via a ROS storm generation strategy in tumor therapy. The experimental results confirm and demonstrate the satisfactory tumor inhibition effect both in vitro and in vivo.

Ultrasound-Triggered Azo Free Radicals for Cervical Cancer Immunotherapy

PD-1 blockade is a first-line treatment for recurrent/metastatic cervical cancer but benefits only a small number of patients due to low preexisting tumor immunogenicity. Using immunogenic cell death (ICD) inducers is a promising strategy for improving immunotherapy, but these compounds are limited by the hypoxic environment of solid tumors. To overcome this issue, the nanosensitizer AIBA@MSNs were designed based on sonodynamic therapy (SDT), which induces tumor cell death under hypoxic conditions through azo free radicals in a method of nonoxygen radicals. Mechanistically, the azo free radicals disrupt both the structure and function of tumor mitochondria by reversing the mitochondrial membrane potential and facilitating the collapse of electron transport chain complexes. More importantly, the AIBA@MSN-based SDT serves as an effective ICD inducer and improves the antitumor immune capacity. The combination of an AIBA@MSN-based SDT with a PD-1 blockade has the potential to improve response rates and provide protection against relapse. This study provides insights into the use of azo free radicals as a promising SDT strategy for cancer treatment and establishes a basic foundation for nonoxygen-dependent SDT-triggered immunotherapy in cervical cancer treatment.

Cepharanthine synergizes with photodynamic therapy for boosting ROS-driven DNA damage and suppressing MTH1 as a potential anti-cancer strategy

OBJECTIVE

Photodynamic therapy (PDT) primarily treats skin diseases or cancer by generating reactive oxygen species (ROS) to damage cellular DNA, yet drug resistance limits its application. To tackle this problem, the present study was carried out to improve the efficacy of chlorin e6 (Ce6)-PDT using Cepharanthine (CEP) as well as to reveal the potential molecular mechanism.

MATERIALS AND METHODS

Lewis lung cancer cell line (LLC) was utilized as the cancer cell model. chlorin e6 (Ce6) acted as the photosensitizer to induce PDT. The in vitro anti-cancer efficacy was measured by CCK-8, Annexin-V/PI staining, and migration assay. The Ce6 uptake was observed using flow cytometry and confocal microscopy. The ROS generation was detected by the DCFH-DA probe. The analysis of MutT Homolog 1 (MTH1) expression, correlation, and prognosis in databases was conducted by bioinformatic. The MTH1 expression was detected through western blots (WB). DNA damage was assayed by WB, immunofluorescent staining, and comet assay.

RESULTS

Ce6-PDT showed robust resistance in lung cancer cells under certain conditions, as evidenced by the unchanged cell viability and apoptosis. The subsequent findings confirmed that the uptake of Ce6 and MTH1 expression was enhanced, but ROS generation with laser irradiation was not increased in LLC, which indicated that the ROS scavenge may be the critical reason for resistance. Surprisingly, bioinformatic and in vitro experiments identified that MTH1, which could prevent the DNA from damage of ROS, was highly expressed in lung cancer and thereby led to the poor prognosis and could be further up-regulated by Ce6 PDT. CEP exhibited a dose-dependent suppressive effect on the lung cancer cells. Further investigations presented that CEP treatment boosted ROS production, thereby resulting in DNA double-strand breakage (DDSB) with activation of MTH1, indicating that CEP facilitated Ce6-PDT-mediated DNA damage. Finally, the combination of CEP and Ce6-PDT exhibited prominent ROS accumulation, MTH1 inhibition, and anti-lung cancer efficacy, which had synergistic pro-DNA damage properties.

CONCLUSION

Collectively, highly expressed MTH1 and the failure of ROS generation lead to PDT resistance in lung cancer cells. CEP facilitates ROS generation of PDT, thereby promoting vigorous DNA damage, inactivating MTH1, alleviating PDT resistance, and ameliorating the anti-cancer efficacy of Ce6-PDT, provides a novel approach for augmented PDT.

Versatile Design of Organic Polymeric Nanoparticles for Photodynamic Therapy of Prostate Cancer

Radical prostatectomy is a primary treatment option for localized prostate cancer (PCa), although high rates of recurrence are commonly observed postsurgery. Photodynamic therapy (PDT) has demonstrated efficacy in treating nonmetastatic localized PCa with a low incidence of adverse events. However, its limited efficacy remains a concern. To address these issues, various organic polymeric nanoparticles (OPNPs) loaded with photosensitizers (PSs) that target prostate cancer have been developed. However, further optimization of the OPNP design is necessary to maximize the effectiveness of PDT and improve its clinical applicability. This Review provides an overview of the design, preparation, methodology, and oncological aspects of OPNP-based PDT for the treatment of PCa.

"Spark" PtMnIr Nanozymes for Electrodynamic-Boosted Multienzymatic Tumor Immunotherapy

Multienzyme-mimicking redox nanozymes capable of efficient reactive oxygen species (ROS) generation and cellular homeostasis disruption are highly pursued for cancer therapy. However, it still faces challenges from the complicate tumor microenvironment (TME) and high chance for tumor metastasis. Herein, well-dispersed PtMnIr nanozymes are designed with multiple enzymatic activities, including catalase (CAT), oxidase (OXD), superoxide dismutase (SOD), peroxidase (POD), and glutathione peroxidase (GPx), which continuously produce ROS and deplete glutathione (GSH) concurrently in an "inner catalytic loop" way. With the help of electrodynamic stimulus, highly active "spark" species (Ir3+ and Mn3+ ) are significantly increased, resulting in an effective cascade enzymatic and electrodynamic therapy. Moreover, the cyclic generation of ROS can also facilitate ferroptosis and apoptosis in tumor cells, boosting synergistic therapy. Importantly, lung metastasis inhibition is found, which confirms efficient immunotherapy by the combined effect of immunogenic cell death (ICD) and Mn2+ -induced cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS)-stimulator of interferon genes (cGAS-STING) pathway, contributing great potential in the treatment of malignant tumors.

Ligand-based active targeting strategies for cancer theranostics

In the past decades, for the intermediate or advanced cancerous stages, preclinical and clinical applications of nanomedicines in cancer theranostics have been extensively studied. Nevertheless, decreased specificity and poor targeting efficiency with low target concentration of theranostic are the major drawbacks of nanomedicine in employing clinical substitution over conventional systemic therapy. Consequently, ligand decorated nanocarrier-mediated targeted drug delivery system can transcend the obstructions through their enhanced retention activity and increased permeability with effective targeting. The highly efficient and specific nanocarrier-mediated ligand-based active therapy is one of the novel and promising approaches for delivery of the therapeutics for different cancers in recent years to restrict various cancer growth in vivo without harming healthy cells. The article encapsulates the features of nanocarrier-mediated ligands in augmentation of active targeting approaches of various cancers and summarizes ligand-based targeted delivery systems in treatment of cancer as plausible theranostics.

Topically applied pH-responsive nanogels for alkyl radical-based therapy against psoriasiform hyperplasia

Phototherapy is a conventional antipsoriatic approach based on oxygen-relevant generation of oxidative stress to inhibit keratinocyte hyperproliferation. However, this therapy can be restricted due to local hypoxia in psoriatic lesions. The generation of alkyl radicals is oxygen-independent and suppresses hyperproliferation. Herein, we established alkyl radical-based therapy to treat psoriatic hyperplasia. Because alkyl radicals are short-lived compounds, we loaded 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIPH) as a precursor of alkyl radicals into the chitosan nanogels to improve stability. The present study presented a topically applied nanogel that led to a pH-responsive network sensitive to skin pH. This pH responsiveness of the nanogels allowed fast alkyl radical release in the target site. The physicochemical properties of the prepared nanogels were determined through size, zeta potential, scanning electron microscopy, and absorption spectroscopy. The antipsoriatic activity was examined with keratinocyte- and animal-based studies. The nanogels displayed a smooth and spherical morphology with a hydrodynamic diameter of 215 nm. This size was largely increased as the environmental pH increased to 6. The nanogels heated at 44 °C produced alkyl radicals to induce keratinocyte death through the necrosis pathway. Bioimaging demonstrated that topically applied nanogels could deliver alkyl radicals into the epidermis. This targeting was accompanied by the accumulation of free radicals in the epidermis according to the 2',7'-dichlorodihydrofluorescein diacetate assay. The imiquimod-stimulated psoriasiform animal model indicated a remarkable reduction in erythema, scaling, and overexpressed cytokines upon topical treatment of the nanogels. The transepidermal water loss of the psoriasiform skin was inhibited from 51.7 to 27.0 g/m2/h, suggesting barrier function recovery by the nanocarriers. The nanogels lowered hyperplasia by decreasing the epidermal thickness from 212 to 89 μm. The incorporation of 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) as a pH-sensitive fluorescence dye in the nanogels could be used to diagnose the severity of the psoriasiform plaque due to the stronger fluorescence of HPTS in skin with lower pH (psoriasiform skin pH = 4.4) than in healthy skin (pH = 4.9). It was possible to deliver the prepared nanogels into the epidermis to restrain hyperplasia without causing cutaneous irritation.

Three-pronged attacks by hybrid nanoassemblies involving a natural product, carbon dots, and Cu2+ for synergistic HCC therapy

Tumor microenvironment (TME) stimuli-responsive nanoassemblies are emerging as promising drug delivery systems (DDSs), which acquire controlled release by structural transformation under exogenous stimulation. However, the design of smart stimuli-responsive nanoplatforms integrated with nanomaterials to achieve complete tumor ablation remains challenging. Therefore, it is of utmost importance to develop TME-based stimuli-responsive DDSs to enhance drug-targeted delivery and release at tumor sites. Herein, we proposed an appealing strategy to construct fluorescence-mediated TME stimulus-responsive nanoplatforms for synergistic cancer therapy by assembling photosensitizers (PSs) carbon dots (CDs), chemotherapeutic agent ursolic acid (UA), and copper ions (Cu2+). First, UA nanoparticles (UA NPs) were prepared by self-assembly of UA, then UA NPs were assembled with CDs via hydrogen bonding force to obtain UC NPs. After combining with Cu2+, the resulting particles (named UCCu2+ NPs) exhibited quenched fluorescence and photosensitization due to the aggregation of UC NPs. Upon entering the tumor tissue, the photodynamic therapy (PDT) and the fluorescence function of UCCu2+ were recovered in response to TME stimulation. The introduction of Cu2+ triggered the charge reversal of UCCu2+ NPs, thereby promoting lysosomal escape. Furthermore, Cu2+ resulted in additional chemodynamic therapy (CDT) capacity by reacting with hydrogen peroxide (H2O2) as well as by consuming glutathione (GSH) in cancer cells through a redox reaction, hence magnifying intracellular oxidative stress and enhancing the therapeutic efficacy due to reactive oxygen species (ROS) therapy. In summary, UCCu2+ NPs provided an unprecedented novel approach for improving the therapeutic efficacy through the three-pronged (chemotherapy, phototherapy, and heat-reinforced CDT) attacks to achieve synergistic therapy.

Recent Progress in Distiller's Grains: Chemical Compositions and Biological Activities

Distiller's grains (DGs) are solid mixtures that remain after the production of alcoholic beverages. A large amount of DGs is produced each year during the brewing process. Currently, they are mostly used as a feedstock or substrate in the feed industry. However, the lack of a comprehensive understanding of the chemical composition of DGs is a major constraint on their further development and application for high-value-added usages. Some studies were published on the bioactive constituents of DGs in several different types of journals. Data were therefore collated to provide a comprehensive overview of these natural products. DGs are rich in phenols, phytosterols, and fatty acids, in addition to general lipid and protein constituents. These compounds and their related extracts possess diverse biological activities, including antioxidant, anti-inflammatory, and anti-hyperglycaemic effects. We hope that this review will provide research incentives for the further development and utilisation of DGs to develop high-value-added products.

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

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

Molecular Docking and In Vivo Biological Studies of Sodium Salt of 3-(4-Methyl-2-oxo-2-H-quinoline-7-yloxy)-3-phenylacrylic Acid As Anticancer Agent

Quinoline derivatives possess several therapeutic properties. Aim: studying the anticancer effect of 3-(4-methyl-2-oxo-2-H-quinoline-7-yloxy)-3-phenylacrylic acid's sodium solution on the Ehrlich ascites carcinoma (EAC). Median lethal dose (LD50) and dose response curve was determined for sodium salt solution of 3-(4-methyl-2-oxo-2-H-quinoline-7-yloxy)-3-phenylacrylic acid, then diving a group of one hundred Swiss albino mice, which are all females, into five groups: group 1: (negative control) where intraperitoneally injected with saline into mice for 10 successive days; group 2 (positive control), also namely (EAC-bearing group): where the EAC cells were intraperitoneally injected into mice (2.5 × 106 cells/mouse) only one time on the first day; group 3 which is defined as the (therapeutic group) where the Na+ salt of the synthetic compound was injected into the peritoneum of the mice (2.5 mg/kg) the very first day after the injection of the EAC, then the compound was injected every two days for a period of 10 days; group 4 which is the (preventive group) where the sodium salt of the synthetic compound (2.5 mg/kg) was injected in the peritoneum of the mice the day before the injection of the EAC, then the compound was successively injected every day for a period of ten days; and group 5 which is the (drug group) in which mice were repeatedly injected) in their peritoneum with the sodium salt of the synthetic compound (2.5 mg/kg on a daily basis over a period of ten days. On the eleventh day of the trial, EAC cells were harvested from each mouse in a heparinized saline, in addition to blood samples, liver and kidney tissues which are also collected. Molecular docking showed that compound's sodium salt was docked into (PDB: 2R7G) and (PDB: 2R3I), which are the retinoblastoma protein receptor and the cyclin D-1 receptor respectively. Compared to those in the positive control group, mice in both the therapeutic and preventive groups, has shown a significant decrease in MDA, cyclin D-1 levels in the tissues of both liver and kidney tissues, in addition to the serum ALT, AST, CK-MB, and LDH activities, and the serum urea and creatinine concentration. However, mice in the formerly mentioned groups, both therapeutic and preventive groups, have shown an increase in the serum albumin, total protein, retinoblastoma protein in both liver and kidney tissues as well as the total antioxidant capacity, when compared to mice in the positive control group. It is worth mentioning that histopathological findings have confirmed that. Sodium salt of 3-(4-methyl-2-oxo-2H-quinoline-7-yloxy)-3-phenylacrylic acid showed potential in vivo anticancer and antioxidant effects against Ehrlich ascites carcinoma cells; (EAC cells).

Lotus-Flower- and Lotus-Seedpod-Derived Polysaccharide: Structural Characterization and Biological Activity

Lotus flower polysaccharide (LFP) and lotus seedpod polysaccharide (LSP) were separated by water extract-alcohol precipitation, and their structures and biological activities were investigated. The results of monosaccharide composition showed that LFP and LSP were composed of nine monosaccharides, fucose, rhamnose, arabinose, glucose, galactose, mannose, fructose, galacturonic acid, and glucuronic acid, with the molar percentages of 0.18: 0.43: 2.26: 45.22: 32.14: 4.28: 8.20: 6.28: 1.01 and 2.70: 1.02: 8.15: 45.63: 20.63: 1.44: 2.59: 16.45. LSP and LFP exhibited molecular weights of 9.37 × 104 Da and 1.24 × 106 Da, respectively. SEM showed that LFP and LSP have similar structures; XRD analysis showed that both polysaccharides had crystalline structure and amorphous structure. The results of ABTS+, DPPH, hydroxyl radical scavenging experiment, and a reducing power experiment showed that LFP and LSP had good antioxidant capacity. Cell viability findings showed that polysaccharide concentrations of lotus flower and lotus seedpod could enhance cellular proliferation ranging from 25 to 400 μg/mL without cytotoxicity. By inducing the production of crucial proteins in the TLR4/NF-κB pathway, LFP and LSP were able to induce autophagy in RAW264.7, according to the results of the RT-PCR and Western blotting assays.

Inorganic nanoparticle agents for enhanced chemodynamic therapy of tumours

With the recent interest in the role of oxidative species/radicals in diseases, inorganic nanomaterials with redox activities have been extensively investigated for their potential use in nanomedicine. While many studies focusing on relieving oxidative stress to prevent pathogenesis and to suppress the progression of diseases have shown considerable success, another approach for increasing oxidative stress using nanomaterials to kill malignant cells has suffered from low efficiency despite its wide applicability to various targets. Chemodynamic therapy (CDT) is an emerging technique that can resolve such a problem by exploiting the characteristic tumour microenvironment to achieve high selectivity. In this review, we summarize the recent strategies and underlying mechanisms that have been used to improve the CDT performance using inorganic nanoparticles. In addition to the design of CDT agents, the effects of contributing factors, such as the acidity and the levels of hydrogen peroxide and antioxidants in the tumour microenvironment, together with their modulation and application in combination therapy, are presented. The challenges lying ahead of future clinical translation of this rapidly advancing technology are also discussed.

Red emitting carbon dots: surface modifications and bioapplications

Quantum dots (QDs), and carbon quantum dots (CDs) in particular, have received significant attention for their special characteristics. These particles, on the scale of several nanometers, are often produced using simple and green methods, with naturally occurring organic precursors. In addition to facile production methods, CDs present advantageous applications in the field of medicine, primarily for bioimaging, antibacterial and therapeutics. Also, CDs present great potential for surface modification through methods like doping or material mixing during synthesis. However, the bulk of current literature focuses on CDs emitting in the blue wavelengths which are not very suitable for biological applications. Red emitting CDs are therefore of additional interest due to their brightness, photostability, novelty and deeper tissue penetration. In this review article, red CDs, their methods of production, and their biological applications for translational research are explored in depth, with emphasis on the effects of surface modifications and doping.

Porous SiO2-Based Reactor with Self-Supply of O2 and H2O2 for Synergistic Photo-Thermal/Photodynamic Therapy

Purpose

Although the combined photo-thermal (PTT) and photodynamic therapy (PDT) of tumors have demonstrated promise as effective cancer therapy, the hypoxic and insufficient H₂O₂ supply of tumors seriously limits the efficacy of PDT, and the acidic environment reduces the catalytic activity of nanomaterial in the tumor microenvironment. To develop a platform for efficiently addressing these challenges, we constructed a nanomaterial of Aptamer@dox/GOD-MnO₂-SiO₂@HGNs-Fc@Ce6 (AMS) for combination tumor therapy. The treatment effects of AMS were evaluated both in vitro and in vivo.

Methods

In this work, Ce6 and hemin were loaded on graphene (GO) through π-π conjugation, and Fc was connected to GO via amide bond. The HGNs-Fc@Ce6 was loaded into SiO₂, and coated with dopamine. Then, MnO₂ was modified on the SiO₂. Finally, AS1411-aptamer@dox and GOD were fixed to gain AMS. We characterized the morphology, size, and zeta potential of AMS. The oxygen and reactive oxygen species (ROS) production properties of AMS were analyzed. The cytotoxicity of AMS was detected by MTT and calcein-AM/PI assays. The apoptosis of AMS to a tumor cell was estimated with a JC-1 probe, and the ROS level was detected with a 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) probe. The anticancer efficacy in vivo was analyzed by the changes in the tumor size in different treatment groups.

Results

AMS was targeted to the tumor cell and released doxorubicin. It decomposed glucose to produce H₂O₂ in the GOD-mediated reaction. The generated sufficient H₂O₂ was catalyzed by MnO₂ and HGNs-Fc@Ce6 to produce O₂ and free radicals (•OH), respectively. The increased oxygen content improved the hypoxic environment of the tumor and effectively reduced the resistance to PDT. The generated •OH enhanced the ROS treatment. Moreover, AMS depicted a good photo-thermal effect.

Conclusion

The results revealed that AMS had an excellent enhanced therapy effect by combining synergistic PTT and PDT.

Functional Bioactivities of Soluble Seed Proteins from Two Leguminous Seeds

Storage proteins from Sphenostylis stenocarpa and Phaseolus lunatus were fractionated, and their in vitro bioactivities were investigated. Albumin, globulin, prolamin, and glutelin constituents of the respective seeds were successively fractionated using the modified Osborne method. Phenylmethylsulfonyl fluoride (1 mM) was used as a protease inhibitor. The antioxidant, anti-inflammatory, and acetylcholinesterase-inhibitory activities of the protein fractions were evaluated using different appropriate techniques. Globulin was the predominant fraction, with a yield of 43.21±0.01% and 48.19±0.03% for S. stenocarpa and P. lunatus, respectively, whereas prolamin was not detected in both seeds. The protein fraction markedly scavenges hydroxyl radicals, nitric oxide radicals, and 2,2-diphenyl-1-picryldydrazyl radicals with concomitant high free radical-reducing power. Albumin and globulin fractions elicited the highest acetylcholinesterase-inhibitory potential of 48.75% and 49.75%, respectively, indicating their great application potential in managing neurodegenerative diseases. In this study, the albumin, globulin, and glutelin fractions of these underutilized legumes showed great analeptic bioactivities, which could be utilized as health-promoting dietary supplements/products.

Mechanisms of Action of Fruit and Vegetable Phytochemicals in Colorectal Cancer Prevention

Colorectal cancer (CRC) is the third most common cancer worldwide and its incidence is expected to increase by almost 80% by 2030. CRC apparition is related to poor diet, mainly due to low consumption of phytochemicals present in fruits and vegetables. Hence, this paper reviews the most promising phytochemicals in the literature, presenting scientific evidence regarding potential CRC chemopreventive effects. Moreover, this paper reveals the structure and action of CRC mechanisms that these phytochemicals are involved in. The review reveals that vegetables rich in phytochemicals such as carrots and green leafy vegetables, as well as some fruits such as pineapple, citrus fruits, papaya, mango, and Cape gooseberry, that have antioxidant, anti-inflammatory, and chemopreventive properties can promote a healthy colonic environment. Fruits and vegetables in the daily diet promote antitumor mechanisms by regulating cell signaling and/or proliferation pathways. Hence, daily consumption of these plant products is recommended to reduce the risk of CRC.

Flower-like Nanozyme with Highly Porous Carbon Matrix Induces Robust Oxidative Storm against Drug-Resistant Cancer

Reactive oxygen species (ROS) generators are sparking breakthroughs in sensitization and treatment of therapy-resistant tumors, yet the efficacy is drastically compromised by limited substrate concentrations, short lifetimes of free radicals, and restricted oxidative damage. Herein, a flower-like nanozyme with highly permeable leaflets accommodating catalytic metal sites was developed to address the challenges by boosting substrate and product accessibility. In the formation of a zeolite imidazole framework, cobalt ions promoted catalytic polymerization and deposition of polydopamine. The polymers acted as a stiffener for preventing framework collapse and maneuvering pore reopening during carbonization. The cobalt single-atom/cluster sites in the highly porous matrix generated peroxidase/oxidase-like activities with high catalytic efficiency (K_cat/K_m) up to 6 orders of magnitude greater than that of conventional nano-/biozymes. Thereby, a robust ROS storm induced by selective catalysis led to rapid accumulation of oxidative damage and failure of antioxidant and antiapoptotic defense synchronization in drug-resistant cancer cells. By synergy of a redox homeostasis disrupter co-delivered, a significantly high antitumor efficiency was realized in vivo. This work offers a route to kinetically favorable ROS generators for advancing the treatment of therapy-resistant tumors.

Polydopamine nanoparticles coated with a metal-polyphenol network for enhanced photothermal/chemodynamic cancer combination therapy

Polydopamine nanoparticles (PDA NPs) are commonly used for photothermal therapy (PTT) of cancer because of their good biocompatibility and photothermal conversion capability. However, it is difficult to achieve a good tumor inhibition effect with a single PTT of PDA. Therefore, in this work, we prepared a combined anticancer nanosystem for enhanced chemodynamic therapy (CDT)/PTT by coating PDAs with an (-)-epigallocatechin gallate (EGCG)/iron (Fe) metal-polyphenol network (MPN). The MPN shell of this nanosystem named EGCG@PDA is degraded by the weakly acidic environment intracellular, releasing EGCG and Fe³⁺. EGCG inhibits the expression of heat shock proteins (HSPs) in cancer cells, thus eliminating their thermal protection against cancer cells for enhanced PTT. Meanwhile, the reductive EGCG can also reduce Fe³⁺ to Fe²⁺, to catalyze the decomposition of overexpressed hydrogen peroxide (H₂O₂) in cancer cells to generate strong oxidative hydroxyl radicals (OH), i.e., catalyzing the Fenton reaction, for CDT. After the Fenton reaction, the re-oxidized Fe ions can be reduced again by EGCG and reused to catalyze the Fenton reaction, which can achieve enhanced CDT. Both in vitro and in vivo studies have shown that EGCG@PDA has low dark toxicity and good anticancer effects. It is expected to be used for precision cancer therapy.

Nanozyme-like single-atom catalyst combined with artesunate achieves photothermal-enhanced nanocatalytic therapy in the near-infrared biowindow

Selectively generating active free radical (AFR) in tumor microenvironment (TME) can promote irreversible oxidation of biomolecules and damage tumor cells, resulting in effective tumor inhibition. However, therapeutic efficacy of AFR-based tumor suppression approaches is often limited by insufficient amount of H₂O₂ or O₂ within TME. To overcome this obstacle, we design a pH/photothermal dual responsive nanosystem (PFeSA@AS) for combined photothermal and nanocatalytic therapy in the near-infrared biowindow. Here the Fe single-atom dispersed N, S-doped carbon nanosheets (FeSA) nanozyme is dispersed by phospholipid-polyethylene glycol-amine (DSPE-PEG-NH₂), and further loads artesunate (AS) via an amide reaction. Upon 808-nm laser irradiation in TME, the AS is released and further be catalyzed by the FeSA nanozyme to produce cytotoxic C-centered AFRs, and further be accelerated due to the photothermal conversion performance of FeSA (23.35%). The nanocatalytic process of FeSA nanozyme is realized by density functional theory (DFT). The tumor inhibition rates of a CT26 xenograft model is 92% through a photothermal-enhanced nanocatalytic synergistic therapy, and negligible systematic toxicity is observed. This work offers a potential paradigm of multifunctional single atomic catalysts (SACs) for enhancing tumor nanocatalytic therapy. STATEMENT OF SIGNIFICANCE: We designed a pH/photothermal dual responsive nanosystem (PFeSA@AS) for nanocatalytic therapy: (1) the nanosystem responsively releases AS under 808-nm laser irradiation in TME; (2) FeSA in the nanosystem can act as heme mimetic to convert AS into high cytotoxic C-centered free radicals for nanocatalytic therapy; (3) the photothermal conversion performance of FeSA further enhances the catalytic process to yield abundant AFR. Both in vitro and in vivo results demonstrate that this nanosystem can efficiently inhibit tumor growth through a photothermal-enhanced nanocatalytic synergistic therapy.

An Ultrasound-Triggered Nanoplatform for Synergistic Sonodynamic-Nitric Oxide Therapy

Ultrasound (US)-triggered sonodynamic therapy (SDT) has aroused intensive interest as a powerful alternative for cancer treatment in recent years due to its non-invasiveness and deep tissue penetration. However, the therapeutic effect of SDT alone is still limited by intrinsic hypoxia in solid tumors. Combined synergistic therapy strategies are highly desired for improving therapeutic efficiency. Herein, a rationally designed intelligent theranostic nanoplatform is developed for the enhancement of cancer treatment through synergistic SDT and nitric oxide (NO) therapy. This US-triggered nanoplatform is fabricated by integrating a sonosensitizer Rose Bengal (RB) and a NO donor (SNO) into manganese-doped hollow mesoporous silica nanoparticles (MH-SNO@RB). Impressively, the acidic and reducing tumor microenvironment accelerates the sustainable release of Mn ions from the framework, which facilitates the MH-SNO@RB to be used as a contrast agent for magnetic resonance imaging. More importantly, the reactive oxygen species (ROS) generated by RB and NO molecules released from SNO, which are simultaneously triggered by US, can react with each other to yield highly reactive peroxynitrite (ONOO^-) ions for effective tumor inhibition both in vitro and in vivo. Furthermore, the nanoplatform demonstrates good hemocompatibility and histocompatibility. This study opens a new strategy for the full utilization of US and intelligent design avenues for high-performance cancer treatment.

Single Atom-Doped Nanosonosensitizers for Mutually Optimized Sono/Chemo-Nanodynamic Therapy of Triple Negative Breast Cancer

Sonodynamic therapy (SDT) represents a promising therapeutic modality for treating breast cancer, which relies on the generation of abundant reactive oxygen species (ROS) to induce oxidative stress damage. However, mutant breast cancers, especially triple-negative breast cancer (TNBC), have evolved to acquire specific antioxidant defense functions, significantly limiting the killing efficiency of SDT. Herein, the authors have engineered a distinct single copper atom-doped titanium dioxide (Cu/TiO2 ) nanosonosensitizer with highly catalytic and sonosensitive activities for synergistic chemodynamic and sonodynamic treatment of TNBC. The single-atom Cu is anchored on the most stable Ti vacancies of hollow TiO2 sonosensitizers, which not only substantially improved the catalytic activity of Cu-mediated Fenton-like reaction, but also considerably augmented the sonodynamic efficiency of TiO2 by facilitating the separation of electrons (e- ) and holes (h+ ). Both the in vitro and in vivo studies demonstrate that the engineered single atom-doped nanosonosensitizers effectively achieved the significantly inhibitory effect of TNBC, providing a therapeutic paradigm for non-invasive and safe tumor elimination through the mutual process of sono/chemo-nanodynamic therapy based on multifunctional single-atom nanosonosensitizers.

Carbon dots nanophotosensitizers with tunable reactive oxygen species generation for mitochondrion-targeted type I/II photodynamic therapy

Carbon dots (CDs) have emerged as promising nanomaterials for bioimaging-guided photodynamic therapy (PDT). However, designing red-emissive CDs (RCDs) with tunable type I and type II reactive oxygen species (ROS) generation to simultaneously meet PDT applications in aerobic and hypoxic scenarios still remain major challenges. Herein, three types of RCDs with maximum emission at approximately 680 nm are successfully prepared. It is noteworthy that they exhibit the adjustable ROS production with equal superoxide anion (via type I PDT) and incremental singlet oxygen (via type II PDT). Detailed structural and optical characterizations along with theoretical calculation reveal that the unique type I/II ROS formation mainly depends on the core sizes and surface states of RCDs, which determine their identical redox potentials and tapering energy gaps between singlet- and triplet states, respectively. Additionally, due to the inherent mitochondria targeting capability, RCDs enable themselves to induce cell programmed death via activating mitochondrion-mediated apoptotic pathways. This work exploits the unprecedented RCDs with tunable type I and type II ROS generation that could ensure highly efficient tumor eradication both in vitro and in vivo, even under the harsh tumor microenvironment, providing a new prospect for CDs as nanophotosensitizers to conquer the limitations of single type PDT.

Immunogenic sonodynamic therapy for inducing immunogenic cell death and activating antitumor immunity

Immunotherapy is widely regarded as a promising treatment for cancer. However, the immune effector phase suppression of tumor microenvironment (TME) and the generation of immune-related adverse events limit its application. Research indicates that sonodynamic therapy (SDT) can effectively activate antitumor immunity while killing tumor cells. SDT produces cytotoxic substances of tumors, and then cell apoptosis and immunogenic death occur by selectively activating the sonosensitizer under ultrasound. In recent years, various SDT alone as well as SDT in combination with other therapies have been developed to induce immunogenic cell death (ICD) and enhance immunotherapy. This paper overviews the research progress of SDT and nanotechnology in recent years, including the strategies involving SDT alone, SDT-based synergistic induction of antitumor immunity, and immunotherapy based on SDT for multimodal immunotherapy. Finally, the prospects and challenges of these SDT-based therapies in cancer immunotherapy are discussed.

Recent Progress in Type I Aggregation-Induced Emission Photosensitizers for Photodynamic Therapy

In modern medicine, precision diagnosis and treatment using optical materials, such as fluorescence/photoacoustic imaging-guided photodynamic therapy (PDT), are becoming increasingly popular. Photosensitizers (PSs) are the most important component of PDT. Different from conventional PSs with planar molecular structures, which are susceptible to quenching effects caused by aggregation, the distinct advantages of AIE fluorogens open up new avenues for the development of image-guided PDT with improved treatment accuracy and efficacy in practical applications. It is critical that as much of the energy absorbed by optical materials is dissipated into the pathways required to maximize biomedical applications as possible. Intersystem crossing (ISC) represents a key step during the energy conversion process that determines many fundamental optical properties, such as increasing the efficiency of reactive oxygen species (ROS) production from PSs, thus enhancing PDT efficacy. Although some review articles have summarized the accomplishments of various optical materials in imaging and therapeutics, few of them have focused on how to improve the phototherapeutic applications, especially PDT, by adjusting the ISC process of organic optics materials. In this review, we emphasize the latest advances in the reasonable design of AIE-active PSs with type I photochemical mechanism for anticancer or antibacterial applications based on ISC modulation, as well as discuss the future prospects and challenges of them. In order to maximize the anticancer or antibacterial effects of type I AIE PSs, it is the aim of this review to offer advice for their design with the best energy conversion.

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.

Nanodiamond-Based Optical-Fiber Quantum Probe for Magnetic Field and Biological Sensing

Owing to the unique electronic spin properties, nitrogen-vacancy (NV) centers hosted in diamond have emerged as a powerful quantum tool for detecting various physical parameters and biological species. In this work, an optical-fiber quantum probe, configured by chemically modifying nanodiamonds on the surface of a cone fiber tip, is developed. Based on the continuous-wave optically detected magnetic resonance method and lock-in amplification technique, it is found that the sensing performance of probes can be engineered by varying the nanodiamond dispersion concentration and modification duration during the chemical modification process. Combined with a pair of magnetic flux concentrators, the magnetic field detection sensitivity has reached 0.57 nT/Hz^1/2@1 Hz, a new record among the fiber magnetometers based on nanodiamonds. Taking Gd³⁺ as the demo, the capability of probes in paramagnetic species detection is also demonstrated experimentally. Our work provides a new approach to develop NV centers as quantum probes featuring high integration, multifunction, high sensitivity, etc.

Novel Approaches for the Solid-Phase Synthesis of Dihydroquinazoline-2(1H)-One Derivatives and Biological Evaluation as Potential Anticancer Agents

In the design of antineoplastic drugs, quinazolinone derivatives are often used as small molecule inhibitors for kinases or receptor kinases, such as the EGFR tyrosine kinase inhibitor gefitinib, p38MAP kinase inhibitor DQO-501, and BRD4 protein inhibitor PFI-1. A novel and convenient approach for the solid-phase synthesis of dihydroquinazoline-2(1H)-one derivatives was proposed and 19 different compounds were synthesized. Cytotoxicity tests showed that most of the target compounds had anti-proliferative activity against HepG-2, A2780 and MDA-MB-231 cell lines. Among them, compounds CA1-e and CA1-g had the most potent effect on A2780 cells, with IC₅₀ values of 22.76 and 22.94 μM, respectively. In addition, in an antioxidant assay, the IC₅₀ of CA1-7 was 57.99 μM. According to bioinformatics prediction, ERBB2, SRC, TNF receptor, and AKT1 were predicted to be the key targets and play an essential role in cancer treatment. ADMET prediction suggested 14 of the 19 compounds had good pharmacological properties, i.e., these compounds displayed clinical potential. The correct structure of the final compounds was confirmed based on LC/MS, ¹H NMR, and ¹³C NMR.

Supramolecular Coassembled Peptide Hydrogels for Efficient Anticancer Therapy by RNS-Based PDT and Immune Microenvironment Regulation

Photodynamic therapy (PDT) has attracted much attention in cancer treatment due to its tumor selectivity and noninvasive nature. Recent studies have demonstrated that PDT mediated reactive oxygen species (ROS) generation in tumor microenvironment (TME) synergistically improves the efficacy of immune checkpoint blockade (ICB) therapy. However, the instability and short half-life of the ROS generated by PDT limit its clinical applications. Herein, a coassembled peptide hydrogel comprising two short peptides that contained the same assembly unit, Ce6-KKFKFEFEF (KEF-Ce6) and RRRRRRRR-KFKFEFEF (KEF-R8) is developed. When exposed to 635 nm laser irradiation, KEF-Ce6 released ROS, while KEF-R8 plays as nitric oxide (NO) donor. Subsequently, ROS reacts with NO to produce reactive nitrogen species (RNS). Both in vitro and in vivo experiments prove that converting ROS into more cytotoxic RNS caused intense cell death. Importantly, it is observed that tumor-associated macrophages (TAMs) are polarized to proinflammatory types (M1-type) by the RNS-based PDT. The increase of M1 macrophages relieves the immunosuppressive situation in TME. Thus, when combined with αPD-L1 treatment, the survival time of tumor-bearing mice is prolonged. Overall, a simple yet efficient coassembled hydrogel that can cascade release ROS/NO/RNS and strengthen antitumor T cell responses to boost cancer immunotherapy by reprogramming TAMs is provided.

Reductive damage induced autophagy inhibition for tumor therapy

Numerous therapeutic anti-tumor strategies have been developed in recent decades. However, their therapeutic efficacy is reduced by the intrinsic protective autophagy of tumors. Autophagy plays a key role in tumorigenesis and tumor treatment, in which the overproduction of reactive oxygen species (ROS) is recognized as the direct cause of protective autophagy. Only a few molecules have been employed as autophagy inhibitors in tumor therapy to reduce protective autophagy. Among them, hydroxychloroquine is the most commonly used autophagy inhibitor in clinics, but it is severely limited by its high therapeutic dose, significant toxicity, poor reversal efficacy, and nonspecific action. Herein, we demonstrate a reductive-damage strategy to enable tumor therapy by the inhibition of protective autophagy via the catalytic scavenging of ROS using porous nanorods of ceria (PN-CeO2) nanozymes as autophagy inhibitor. The antineoplastic effects of PN-CeO2 were mediated by its high reductive activity for intratumoral ROS degradation, thereby inhibiting protective autophagy and activating apoptosis by suppressing the activities of phosphatidylinositide 3-kinase/protein kinase B and p38 mitogen-activated protein kinase pathways in human cutaneous squamous cell carcinoma. Further investigation highlighted PN-CeO2 as a safe and efficient anti-tumor autophagy inhibitor. Overall, this study presents a reductive-damage strategy as a promising anti-tumor approach that catalytically inhibits autophagy and activates the intrinsic antioxidant pathways of tumor cells and also shows its potential for the therapy of other autophagy-related diseases.

Electronic Supplementary Material

Supplementary material (cellular uptake of PN-CeO2, effects of PN-CeO2 on several common malignant tumor models, viability of HaCaT cells treated with PN-CeO2 at different concentrations, time-dependent body-weight curves of SCL-1 tumor-bearing nude mice, the biodistribution of Ce element in main tissues and tumors after injection of PN-CeO2, measurement of Ce element concentration in urine and feces samples, H&E-stained images of main organs, and measurement of liver and kidney function in mice after different treatment) is available in the online version of this article at 10.1007/s12274-022-5139-z.

Integrated chromatographic approach for the discovery of gingerol antioxidants from Dracocephalum heterophyllum and their potential targets

As a traditional Tibetan medicine, Dracocephalum heterophyllum has many benefits, but due to the complicated procedures of separation and purification of its chemical constituents, there are few reports on gingerols. In this study, four antioxidative gingerols were isolated from Dracocephalum heterophyllum by an integrated chromatographic approach. Antioxidant activity was then determined by in vitro experiments and its potential targets of action were investigated. First, the extract was pretreated using silica gel, MCI GEL®CHP20P, and diol and spherical medium pressure columns, while the antioxidant peaks were identified using an online HPLC-1,1-diphenyl-2-picrylhydrazyl system. Then, the antioxidant peaks were directionally separated and purified by high pressure liquid chromatography to obtain four gingerols with a purity higher than 95%, namely 5-methoxy-6-gingerol, 6-shogaol, 6-paradol, and diacetoxy-6-gingerdiol. Finally, 1,1-diphenyl-2-picrylhydrazyl assays and cellular antioxidant experiments were carried out, and molecular docking was used to explore potential antioxidant targets. The isolated gingerols upregulated the activity of antioxidant enzymes, including superoxide dismutase (SOD), heme oxygenase-1 (HO-1) and NADPH oxidase 2 (NOX2), while they had little effect on the activity of nadph:quinone oxidoreductase-1 (NQO1). This method can efficiently prepare and isolate antioxidative gingerols from Dracocephalum heterophyllum, and it can be extended to isolate antioxidants from other natural products.

The single-atom iron nanozyme mimicking peroxidase remodels energy metabolism and tumor immune landscape for synergistic chemodynamic therapy and photothermal therapy of triple-negative breast cancer

Chemotherapy, as one main strategy to relieve tumor progression, has a weak effect on triple-negative breast cancer (TNBC) chest wall metastasis. The development of near-infrared (NIR) light-responsive nanomaterials for chemodynamic therapy (CDT) and photothermal therapy (PTT) is a promising platform but still challenging in biomedicine. This study reports a peroxidase mimicking nanozyme (Fe-N-C SAzyme) against TNBC by CDT and PTT. Fe-N-C SAzyme generated reactive oxygen species (ROS) by decomposing H2O2 into hydroxyl radicals (•OH) and also induced light-to-heat conversion under the exposure of 808 nm laser irradiation. With these biological characteristics, the obtained Fe-N-C SAzymes displayed enhanced cell cytotoxicity and inhibition of cancer cell proliferation both in vitro and in vivo at a low dose of nanoagent and a moderate NIR laser power density. Besides, Fe-N-C nanoagent with its excellent ROS generation brought metabolic reprogramming of elevated glycolysis in tumor cells. In vivo experiments, when combined with PTT, the enhanced antitumor effect was found by the elimination of M-MDSC in tumor microenvironment. Fe-N-C SAzymes can serve as a new synergistic CDT and PTT nanoagent to simultaneously reprogram tumor metabolism and tumor microenvironment. It will provide prospects for chemodynamic/photothermal combined cancer therapy for TNBC chest wall metastasis based on the use of a single nanosystem.

Application and prospect of ROS-related nanomaterials for orthopaedic related diseases treatment

The importance of reactive oxygen species (ROS) in the occurrence and development of orthopaedic related diseases is becoming increasingly prominent. ROS regulation has become a new method to treat orthopaedic related diseases. In recent years, the application of nanomaterials has become a new hope for precision and efficient treatment. However, there is a lack of reviews on ROS-regulated nanomaterials for orthopaedic related diseases. Based on the key significance of nanomaterials for the treatment of orthopaedic related diseases, we searched the latest related studies and reviewed the nanomaterials that regulate ROS in the treatment of orthopaedic related diseases. According to the function of nanomaterials, we describe the scavenging of ROS related nanomaterials and the generation of ROS related nanomaterials. In this review, we closely integrated nanomaterials with the treatment of orthopaedic related diseases such as arthritis, osteoporosis, wound infection and osteosarcoma, etc., and highlighted the advantages and disadvantages of existing nanomaterials. We also looked forward to the design of ROS-regulated nanomaterials for the treatment of orthopaedic related diseases in the future.

Dual-responsive and NIR-driven free radical nanoamplifier with glutathione depletion for enhanced tumor-specific photothermal/thermodynamic/chemodynamic synergistic Therapy

The efficacy of free radical-based therapeutic strategies is severely hindered by nonspecific accumulation, premature release and glutathione (GSH) scavenging effects. Herein, a tumor microenvironment-responsive MPDA/AIPH@Cu-TA@HA (abbreviated as MACTH) nanoplatform was constructed by coating Cu²⁺ and tannic acid (TA) on the surface of azo initiator (AIPH)-loaded mesoporous polydopamine (MPDA) nanoparticles and further modifying them with hyaluronic acid (HA) to achieve tumor-specific photothermal/thermodynamic/chemodynamic synergistic therapy (PTT/TDT/CDT). Once accumulated and internalized into cancer cells through CD44 receptor-mediated active targeting and endocytosis, the HA shell of MACTH would be preliminarily degraded by hyaluronidase (HAase) to expose the Cu-TA metal-phenolic networks, which would further dissociate in response to an acidic lysosomal environment, leading to HAase/pH dual-responsive release of Cu²⁺ and AIPH. On the one hand, the released Cu²⁺ could deplete the overexpressed GSH via redox reactions and produce Cu⁺, which in turn catalyzes endogenous H₂O₂ into highly cytotoxic hydroxyl radicals (˙OH) for CDT. On the other hand, the local hyperthermia generated by MACTH under 808 nm laser irradiation could not only augment CDT efficacy through accelerating the Cu⁺-mediated Fenton-like reaction, but also trigger the decomposition of AIPH to produce biotoxic alkyl radicals (˙R) for TDT. The consumption of GSH and accumulation of oxygen-independent free radicals (˙OH/˙R) synergistically amplified intracellular oxidative stress, resulting in substantial apoptotic cell death and significant tumor growth inhibition. Collectively, this study provides a promising paradigm for customizing stimuli-responsive free radical-based nanoplatforms to achieve accurate and efficacious cancer treatment.

Nitric oxide-mediated regulation of mitochondrial protective autophagy for enhanced chemodynamic therapy based on mesoporous Mo-doped Cu9S5 nanozymes

The depletion of reactive oxygen species (ROS) by glutathione (GSH) and oxidative stress induced protective autophagy severely impaired the therapeutic effect of chemodynamic therapy (CDT). Therefore, how to construct a CDT treatment nanosystem with high yield and full utilization of ROS in tumor site is the main issue of CDT. Herein, a multifunctional cascade bioreactor based on mesoporous Mo-doped Cu₉S₅ (m-MCS) nanozymes loaded with L-Arginine (LA), abbreviated as m-MCS@LA, is constructed for realizing enhanced CDT promoted by ultrasound (US) triggered gas therapy. The m-MCS based on the catalytic performance of multivalent metal ions, which were served as nanozymes, exhibit enhanced Fenton-like and glutathione (GSH) peroxidase-like activities in comparison to Cu₉S₅ nanoparticles without Mo-doping. Once placed in tumor microenvironment (TME), the existence of redox couples (Cu⁺/Cu²⁺ and Mo⁴⁺/Mo⁶⁺) in m-MCS enabled it to react with hydrogen peroxide (H₂O₂) to generate ·OH for achieving CDT effect via Fenton-like reaction. Meanwhile, m-MCS could consume overexpressed GSH in tumor microenvironment (TME) to alleviate antioxidant capability for enhancing CDT effect. Moreover, m-MCS with mesoporous structure could be employed as the carrier to load natural nitric oxide (NO) donor LA. US as the excitation source with high tissue penetration can trigger m-MCS@LA to produce NO. As the gas transmitter with physiological functions, NO could play dual roles to kill cancer cells through gas therapy directly, and enhance CDT effect by inhibiting protective autophagy simultaneously. As a result, this US-triggered and NO-mediated synergetic cancer chemodynamic/gas therapy based on m-MCS@LA NPs can effectively eliminate primary tumor and achieved tumor-specific treatment, which provide a possible strategy for developing more effective CDT in future practical applications. STATEMENT OF SIGNIFICANCE: The depletion of reactive oxygen species (ROS) by glutathione (GSH) and oxidative stress induced protective autophagy severely impaired the therapeutic effect of chemodynamic therapy (CDT). Herein, a multifunctional cascade bioreactor based on mesoporous Mo-doped Cu₉S₅ (m-MCS) nanozymes loaded with L-Arginine (m-MCS@LA) is constructed for realizing enhanced CDT promoted by ultrasound (US) triggered gas therapy. The m-MCS with double redox couples presents the enhanced enzyme-like activities to perform cascade reactions for reducing GSH and generating ROS. LA loaded by m-MCS can produce NO triggered by US to inhibit the mitochondria protective autophagy for reactivating mitochondria involved apoptosis pathway. The US-triggered and NO-mediated CDT based on m-MCS@LA can effectively eliminate primary tumor through the high yield and full utilization of ROS.

Connecting Calcium-Based Nanomaterials and Cancer: From Diagnosis to Therapy

As the indispensable second cellular messenger, calcium signaling is involved in the regulation of almost all physiological processes by activating specific target proteins. The importance of calcium ions (Ca²⁺) makes its "Janus nature" strictly regulated by its concentration. Abnormal regulation of calcium signals may cause some diseases; however, artificial regulation of calcium homeostasis in local lesions may also play a therapeutic role. "Calcium overload," for example, is characterized by excessive enrichment of intracellular Ca²⁺, which irreversibly switches calcium signaling from "positive regulation" to "reverse destruction," leading to cell death. However, this undesirable death could be defined as "calcicoptosis" to offer a novel approach for cancer treatment. Indeed, Ca²⁺ is involved in various cancer diagnostic and therapeutic events, including calcium overload-induced calcium homeostasis disorder, calcium channels dysregulation, mitochondrial dysfunction, calcium-associated immunoregulation, cell/vascular/tumor calcification, and calcification-mediated CT imaging. In parallel, the development of multifunctional calcium-based nanomaterials (e.g., calcium phosphate, calcium carbonate, calcium peroxide, and hydroxyapatite) is becoming abundantly available. This review will highlight the latest insights of the calcium-based nanomaterials, explain their application, and provide novel perspective. Identifying and characterizing new patterns of calcium-dependent signaling and exploiting the disease element linkage offer additional translational opportunities for cancer theranostics.

Iron (Fe)-doped mesoporous 45S5 bioactive glasses: Implications for cancer therapy

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Fe-doped mesoporous 45S5 BGs were successfully synthesized using the sol-gel route.

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Fe-doped MBGs exhibited a particles size of 12 nm with a high surface area of 306 m²/g.

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Fe-doped MBGs could generate H₂O₂ in a cathodic potential higher than −0.2 V.

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Fe-doped MBGs increased the standard rate constant of Electro-Fenton's (EF) reaction up to 38.44 times as compared with the Fe-free glasses.

The utilization of bioactive glasses (BGs) in cancer therapy has recently become quite promising; herein, a series of Fe-doped mesoporous 45S5-based BGs (MBGs) were synthesized via the sol-gel method in the presence of Pluronic P123 as a soft template. The physico-chemical and biological properties of the prepared glasses were well-characterized through structural assessments, thermal analyses, and electron microscopic studies. Electrochemical analyses, including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), were also performed to investigate the actual potential of the Fe₂O₃-containing MBGs in modulating the Fenton's reaction. The XRD results confirmed the glassy state of the Fe-doped samples before immersion in simulated body fluid (SBF). The prepared Fe-doped MBGs exhibited a particle size in the range of 11–86 nm, surface charge of 27–30 mV, S_BET of 95–306 m²/g, and M_s of 0.08 to 0.2 emu/g. The incorporation of Fe₂O₃ led to a negligible decrease in the bioactivity of the glasses. The CV analysis indicated that the Fe-doped MBGs could generate H₂O₂ in a cathodic potential higher than -0.2 V (vs. Ag/AgCl) in the O₂-saturated Na₂SO₄ solution. Additionally, the data of the EIS test revealed that the Fe₂O₃-doped MBGs could increase the standard rate constant of Electro-Fenton's (EF) reaction up to 38.44 times as compared with the Fe-free glasses. In conclusion, Fe-doped 45S5-derived glasses may be useful in cancer therapy strategies due to their capability of activating Fenton's reaction and subsequent production of reactive oxygen species (ROS) such as ^•OH free radicals.

Bladder cancer selective chemotherapy with potent NQO1 substrate co-loaded prodrug nanoparticles

Currently, clinical intravesical instillation chemotherapy has been greatly compromised by the toxicological and physiological factors. New formulations that can specifically and efficiently kill bladder cancer cells are in urgent need to overcome the low residence efficiency and dose limiting toxicity of current ones. The combination of mucoadhesive nanocarriers and cancer cell selective prodrugs can to great extent address these limitations. However, the insignificant endogenous stimulus difference between cancer cells and normal cells in most cases and the high local drug concentration make it essential to develop new drugs with broader selectivity-window. Herein, based on the statistically different NQO1 expression between cancerous and normal bladder tissues, the reactive oxygen species (ROS) activatable epirubicin prodrug and highly potent NQO1 substrate, KP372-1, was co-delivered using a GSH-responsive mucoadhesive nanocarrier. After endocytosis, epirubicin could be promptly activated by the NQO1-dependent ROS production caused by KP372-1, thus specifically inhibiting the proliferation of bladder cancer cells. Since KP372-1 is much more potent than some commonly used NQO1 substrates, for example, β-lapachone, the cascade drug activation could occur under much lower drug concentration, thus greatly lowering the toxicity in normal cells and broadening the selectivity-window during intravesical bladder cancer chemotherapy.

Multivalent Polypeptide and Tannic Acid Cooperatively Iron-Coordinated Nanohybrids for Synergistic Cancer Photothermal Ferroptosis Therapy

Owing to having a unique mechanism to kill cancer cells via the membrane accumulation of lipid peroxide (LPO) and the downregulation of glutathione peroxidase-4 (GPX-4), the ferroptosis therapy (FT) of tumors based on the Fenton reaction of iron nanoparticles has been receiving much attention in the past decade; however, there are some hurdles including the uncontrollable release of iron ions, slower kinetics of the intracellular Fenton reaction, and poor efficacy of FT that need to be overcome. Considering cooperative coordination of a multivalent thiol-pendant polypeptide ligand with iron ions, we put forward a facile strategy for constructing the iron-coordinated nanohybrid of methacryloyloxyethyl phosphorylcholine-grafted polycysteine/iron ions/tannic acid (i.e., PCFT), which could deliver a higher concentration of iron ions into cells. The dynamic and unsaturated coordination in PCFT is favorable for the intracellular stimuli-triggered release and fast Fenton reaction to realize efficient FT, while its intrinsic photothermia would boost the Fenton reaction to induce a synergistic effect between FT and photothermal therapy (PTT). Both immunofluorescence analyses of reactive oxygen species (ROS) and LPO confirmed that the intracellular Fenton reaction resulted in efficient FT, during which process the photothermia greatly boosted ferroptosis, and the Western blot assay corroborated that the expression level of GPX-4 was downregulated by FT and highly degraded by the photothermia to induce synergistic PTT-FT in vitro. Excitingly, by a single intravenous dose of PCFT plus one NIR irradiation, in vivo PTT-FT treatment completely eradicated 4T1 tumors without skin scar and tumor recurrence for 16 days, demonstrating prominent antitumor efficacy, as evidenced by the GPX-4, H&E, and TUNEL assays.