A biomimetic nanozyme/camptothecin hybrid system for synergistically enhanced radiotherapy

Biomimetic liposome amplifying mitochondrial damage to potential cancer radio-immunotherapy

Radiotherapy, despite its precision and non-invasiveness, often fails due to the resistance of cancer stem cells (CSCs), which are characterized by high self-renewal capabilities and superior DNA repair mechanisms. These cells can evade RT and lead to tumor recurrence and metastasis. To address this challenge, a novel delivery system named PB has been introduced. This system combines liposomes with platelet membranes to encapsulate Bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES), thus enhancing its delivery and release specifically at tumor sites. In addition, this system not only targets CSCs effectively but also increases the local concentration of BPTES upon X-ray irradiation, which reduces glutathione levels in tumor cells, thereby increasing oxidative stress and damaging mitochondria. PB-elicited mitochondrial damage as the STING signal initiator, which mediated significant upregulation in the expression of a cGAS-STING pathway-related protein thereby amplifying the STING signal. Systemic intravenous administration of PB remarkably promoted DC maturation and CD8+ T cell infiltration, thus eliciting strong antitumor effects. Overall, this PB system presents a potent method to overcome CSC-related resistance and offers a promising approach for future cancer treatment protocols.

Progress of Nanomaterials Based on Manganese Dioxide in the Field of Tumor Diagnosis and Therapy

As a pivotal transition metal oxide, manganese dioxide (MnO2) has garnered significant attention owing to its abundant reserves, diverse crystal structures and exceptional performance. Nanosizing MnO2 results in smaller particle sizes, larger specific surface areas, optimized material characteristics, and expanded application possibilities. With the burgeoning research efforts in this field, MnO2 has emerged as a promising nanomaterial for tumor diagnosis and therapy. The distinctive properties of MnO2 in regulating the tumor microenvironment (TME) have attracted considerable interest, leading to a rapid growth in research on MnO2-based nanomaterials for tumor diagnosis and treatment. Additionally, MnO2 nanomaterials are also gradually showing up in the regulation of chronic inflammatory diseases. In this review, we mainly summarized the recent advancements in various MnO2 nanomaterials for tumor diagnosis and therapy. Furthermore, we discuss the current challenges and future directions in the development of MnO2 nanomaterials, while also envisaging their potential for clinical translation.

Transition-Metal-Based Nanozymes: Synthesis, Mechanisms of Therapeutic Action, and Applications in Cancer Treatment

Cancer, as one of the leading causes of death worldwide, drives the advancement of cutting-edge technologies for cancer treatment. Transition-metal-based nanozymes emerge as promising therapeutic nanodrugs that provide a reference for cancer therapy. In this review, we present recent breakthrough nanozymes for cancer treatment. First, we comprehensively outline the preparation strategies involved in creating transition-metal-based nanozymes, including hydrothermal method, solvothermal method, chemical reduction method, biomimetic mineralization method, and sol-gel method. Subsequently, we elucidate the catalytic mechanisms (catalase (CAT)-like activities), peroxidase (POD)-like activities), oxidase (OXD)-like activities) and superoxide dismutase (SOD)-like activities) of transition-metal-based nanozymes along with their activity regulation strategies such as morphology control, size manipulation, modulation, composition adjustment and surface modification under environmental stimulation. Furthermore, we elaborate on the diverse applications of transition-metal-based nanozymes in anticancer therapies encompassing radiotherapy (RT), chemodynamic therapy (CDT), photodynamic therapy (PDT), photothermal therapy (PTT), sonodynamic therapy (SDT), immunotherapy, and synergistic therapy. Finally, the challenges faced by transition-metal-based nanozymes are discussed alongside future research directions. The purpose of this review is to offer scientific guidance that will enhance the clinical applications of nanozymes based on transition metals.

Application of Multifunctional Nanozymes in Tumor Therapy

Tumors are one of the main diseases threatening human life and health. The emergence of nanotechnology in recent years has introduced a novel therapeutic avenue for addressing tumors. Through the amalgamation of nanotechnology's inherent attributes with those of natural enzymes, nanozymes have demonstrated the ability to initiate catalytic reactions, modulate the biological microenvironment, and facilitate the adoption of multifaceted therapeutic approaches, thereby exhibiting considerable promise in the realm of cancer treatment. In this Review, the application of nanozymes in chemodynamic therapy, radiotherapy, photodynamic therapy, photothermal therapy, and starvation therapy are summarized. Moreover, a detailed discussion regarding the mechanism of conferring physiotherapeutic functionality upon catalytic nanosystems is provided. It is posited that this innovative catalytic treatment holds significant potential to play a crucial role within the domain of nanomedicine.

Two-dimensional multifunctional nanosheets as radiosensitizers for chemodynamic/radio-therapy

The hypoxia tumor microenvironment and low radiation attenuation coefficient of tumor tissue usually limit the efficiency of radiotherapy. In this study, a two-dimensional multifunctional nano-sensitizer, CuNS@Pt, was prepared to function as a radiosensitizer, enhancing radiotherapy through multiple mechanisms. Numerous active sites were provided for the deposition of X-ray radiation energy by the in-situ chemical reduction of Pt to create functional hybrids on Cu-based nanosheets. CuNS@Pt catalyzed high concentration of endogenous hydrogen peroxide to generate oxygen in tumor microenvironment, alleviating the physiological environment of hypoxic tumors. Additionally, CuNS could reduce the content of intrinsic glutathione (GSH) and catalyze hydrogen peroxide to form hydroxyl radicals (·OH). The generated ·OH could damage mitochondria and destroy redox homeostasis due to the functional inclusion of Cu species, thereby achieving chemodynamic therapy and further improving the radiation effect. Both in vivo and in vitro experiments showed that the nano sensitizer effectively improved the therapeutic efficiency of radiotherapy and had good biological safety. All in all, this study provides a pragmatic and doable platform for maximizing the efficacy of RT in cancer. This study also highlights the future research value of two-dimensional nanomaterials.

Therapeutic application of manganese-based nanosystems in cancer radiotherapy

Radiotherapy is an important therapeutic modality in the treatment of cancers. Nevertheless, the characteristics of the tumor microenvironment (TME), such as hypoxia and high glutathione (GSH), limit the efficacy of radiotherapy. Manganese-based (Mn-based) nanomaterials offer a promising prospect for sensitizing radiotherapy due to their good responsiveness to the TME. In this review, we focus on the mechanisms of radiosensitization of Mn-based nanosystems, including alleviating tumor hypoxia, increasing reactive oxygen species production, increasing GSH conversion, and promoting antitumor immunity. We further illustrate the applications of these mechanisms in cancer radiotherapy, including the development and delivery of radiosensitizers, as well as their combination with other therapeutic modalities. Finally, we summarize the application of Mn-based nanosystems as contrast agents in realizing precision therapy. Hopefully, the present review will provide new insights into the biological mechanisms of Mn-based nanosystems, as well as their applications in radiotherapy, in order to address the difficulties and challenges that remain in their clinical application in the future.

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

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

Engineering Cell Membrane-Cloaked Catalysts as Multifaceted Artificial Peroxisomes for Biomedical Applications

Artificial peroxisomes (APEXs) or peroxisome mimics have caught a lot of attention in nanomedicine and biomaterial science in the last decade, which have great potential in clinically diagnosing and treating diseases. APEXs are typically constructed from a semipermeable membrane that encloses natural enzymes or enzyme-mimetic catalysts to perform peroxisome-/enzyme-mimetic activities. The recent rapid progress regarding their biocatalytic stability, adjustable activity, and surface functionality has significantly promoted APEXs systems in real-life applications. In addition, developing a facile and versatile system that can simulate multiple biocatalytic tasks is advantageous. Here, the recent advances in engineering cell membrane-cloaked catalysts as multifaceted APEXs for diverse biomedical applications are highlighted and commented. First, various catalysts with single or multiple enzyme activities have been introduced as cores of APEXs. Subsequently, the extraction and function of cell membranes that are used as the shell are summarized. After that, the applications of these APEXs are discussed in detail, such as cancer therapy, antioxidant, anti-inflammation, and neuron protection. Finally, the future perspectives and challenges of APEXs are proposed and outlined. This progress review is anticipated to provide new and unique insights into cell membrane-cloaked catalysts and to offer significant new inspiration for designing future artificial organelles.

Oxygen switches: Refueling for cancer radiotherapy

Radiotherapy remains the major therapeutic intervention for tumor patients. However, the hypoxic tumor microenvironment leads to treatment resistance. Recently, a burgeoning number of nano-radiosensitizers designed to increase the oxygen concentration in tumors were reported. These nano radiosensitizers served as oxygen carriers, oxygen generators, and even sustained oxygen pumps, attracting increased research interest. In this review, we focus on the novel oxygen-enrich nano radiosensitizers, which we call oxygen switches, and highlight their influence in radiotherapy through different strategies. Physical strategies-based oxygen switches carried O2 into the tumor via their high oxygen capacity. The chemical reactions to generate O2 in situ were triggered by chemical strategies-based oxygen switches. Biological strategies-based oxygen switches regulated tumor metabolism, remodeled tumor vasculature, and even introduced microorganisms-mediated photosynthesis for long-lasting hypoxia alleviating. Moreover, the challenges and perspectives of oxygen switches-mediated oxygen-enrich radiotherapy were discussed.

Bovine Colostrum Treatment of Specific Cancer Types: Current Evidence and Future Opportunities

Worldwide, the incidence of cancer is on the rise. Current cancer treatments include chemotherapy, radiation therapy, and surgery. Chemotherapy and radiation treatment are typically associated with severe adverse effects and a decline in patients' quality of life. Anti-cancer substances derived from plants and animals need to be evaluated therapeutically as it is cost-effective, have fewer side effects, and can improve cancer patients' quality of life. Recently, bovine colostrum (BC) has attracted the interest of numerous researchers investigating its anti-cancer potential in humans. Dressings loaded with BC are beneficial in treating chronic wounds and diabetic foot ulcers. Lactoferrin, a glycoprotein with potent anti-oxidant, anti-inflammatory, anti-cancer, and anti-microbial effects, is abundant in BC. The BC pills successfully promote the regression of low-grade cervical intraepithelial neoplasia when administered intravaginally. The biological, genetic, and molecular mechanisms driving BC remain to be determined. Oral BC supplements are generally well-tolerated, but some flatulence and nausea may happen. To evaluate the therapeutic effects, long-term safety, and appropriate dosages of BC drugs, well-designed clinical trials are necessary. The purpose of this article is to emphasize the anti-cancer potential of BC and its constituents.

Biomimetic CuS nanoparticles for radiosensitization with mild photothermal therapy and GSH-depletion

Due to its non-invasive and highly effective characteristics, radiotherapy has attracted significant interest in cancer treatment. However, radioresistance of solid tumors caused by a unique tumor microenvironment diminishes the therapeutic effect of cancer radiotherapy. To address this issue, we developed a nanoplatform for tumor-specific targeting to improve radiotherapy. Specifically, hollow CuS nanoparticles were decorated with the platelet cell membrane (PC), endowing this nanoplatform with the therapeutic property of navigating to the tumor region for glutathione (GSH)-depletion photothermal therapy. It was discovered that mild photothermal therapy mediated by PC ameliorated hypoxia in the tumor microenvironment. Meanwhile, GSH, which contributes to repairing radiotherapy-induced DNA double-strand breaks, was depleted by PC in an acidic microenvironment. Therefore, radioresistance could be diminished while cancer cell self-repair was prevented. At therapeutic doses, PC nanoparticles have negligible toxic effects on normal tissues. PC demonstrates promise for both in vivo and in vitro radiosensitization due to its GSH-depletion, photothermal efficiency, and tumor-specific properties.

Manganese-Based Nanozymes: Preparation, Catalytic Mechanisms, and Biomedical Applications

Manganese (Mn) has attracted widespread attention due to its low-cost, nontoxicity, and valence-rich transition. Various Mn-based nanomaterials have sprung up and are employed in diverse fields, particularly Mn-based nanozymes, which combine the physicochemical properties of Mn-based nanomaterials with the catalytic activity of natural enzymes, and are attracting a surge of research, especially in the field of biomedical research. In this review, the typical preparation strategies, catalytic mechanisms, advances and perspectives of Mn-based nanozymes for biomedical applications are systematically summarized. The application of Mn-based nanozymes in tumor therapy and sensing detection, together with an overview of their mechanism of action is highlighted. Finally, the prospective directions of Mn-based nanozymes from five perspectives: innovation, activity enhancement, selectivity, biocompatibility, and application broadening are discussed.

Cancer Cell Membrane Biomimetic Mesoporous Nanozyme System with Efficient ROS Generation for Antitumor Chemoresistance

Single-atom nanozymes (SAZs) with reaction specificity and optimized catalytic properties have great application prospects in tumor therapy. But the complex tumor microenvironment (low content of H2O2) limits its therapeutic effect. In this study, we developed a bionic mesoporous Fe SAZs/DDP nanosystem (CSD) for enhanced nanocatalytic therapy (NCT)/chemotherapy by simultaneously encapsulating the chemotherapeutic drugs cisplatin (DDP) and Fe SAZs with high peroxidase (POD) activity into the cancer cell membrane. CSD could evade immune recognition and actively targets tumor sites, and DDP upregulates endogenous H2O2 levels by activating nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, thereby enhancing SAZs-mediated hydroxyl radical (·OH) production, which subsequently leads to mitochondrial damage and intolerance to chemotherapy drug. We used the HGC27/DDP cell line for in vitro and in vivo experiments. The results showed that CSD achieved good therapeutic benefits, without any side effects such as inflammatory reaction. This system can induce multiple antitumor effect with H2O2 self-supply, mitochondrial damage, and ATP downregulation and eventually lead to chemosensitization.

Nanozyme hydrogel for enhanced alkyl radical generation and potent antitumor therapy

Alkyl radicals (R˙), which do not rely on oxygen generation for causing cellular stress, have been applied in tumor treatment, but a large amount of glutathione (GSH) in the tumor cells reacts with alkyl radicals, thereby reducing their antitumor effect. In this study, an enhanced alkyl radical generation system responsive to near-infrared light was designed. The alkyl radical trigger 2,2'-azobis[2-(2-imidazolin-2-yl)propane]-dihydrochloride (AIPH) and nanozyme pyrite (FeS2) were encapsulated in agarose hydrogel to prepare the AIPH-FeS2-hydrogel (AFH) system. FeS2 can be used as a photothermal agent to convert near-infrared light energy into heat energy, leading to the dissolution of the hydrogel. AIPH is simultaneously induced to produce alkyl radicals. FeS2 can also be used as an oxidative stress amplifier to reduce intracellular GSH content, thereby boosting the therapeutic effect of alkyl radicals. Eventually, the oxygen-independent free radicals generated by the AFH system under near-infrared laser irradiation and photothermal treatment can kill cancer cells through the synergistic oxidation/photothermal effect. The AFH system developed herein provides new insights into enhancing the therapeutic effect of alkyl radicals.

Manganese-based hollow nanoplatforms for MR imaging-guided cancer therapies

Theranostic nanoplatforms integrating diagnostic and therapeutic functions have received considerable attention in the past decade. Among them, hollow manganese (Mn)-based nanoplatforms are superior since they combine the advantages of hollow structures and the intrinsic theranostic features of Mn2+. Specifically, the hollow cavity can encapsulate a variety of small-molecule drugs, such as chemotherapeutic agents, photosensitizers and photothermal agents, for chemotherapy, photodynamic therapy (PDT) and photothermal therapy (PTT), respectively. After degradation in the tumor microenvironment (TME), the released Mn2+ is able to act simultaneously as a magnetic resonance (MR) imaging contrast agent (CA) and as a Fenton-like agent for chemodynamic therapy (CDT). More importantly, synergistic treatment outcomes can be realized by reasonable and optimized design of the hollow nanosystems. This review summarizes various Mn-based hollow nanoplatforms, including hollow MnxOy, hollow matrix-supported MnxOy, hollow Mn-doped nanoparticles, hollow Mn complex-based nanoparticles, hollow Mn-cobalt (Co)-based nanoparticles, and hollow Mn-iron (Fe)-based nanoparticles, for MR imaging-guided cancer therapies. Finally, we discuss the potential obstacles and perspectives of these hollow Mn-based nanotheranostics for translational applications. Mn-based hollow nanoplatforms such as hollow MnxOy nanoparticles, hollow matrix-supported MnxOy nanoparticles, Mn-doped hollow nanoparticles, Mn complex-based hollow nanoparticles, hollow Mn-Co-based nanoparticles and hollow Mn-Fe-based nanoparticles show great promise in cancer theranostics.

Synthesis of dihydrofuran-3-one and 9,10-phenanthrenequinone hybrid molecules and biological evaluation against colon cancer cells as selective Akt kinase inhibitors

A series of dihydrofuran-3-one and 9,10-phenanthrenequinone hybrid compounds were synthetized through a one-pot gold-catalyzed oxidative cyclization and Aldol-type addition cascade reaction of homopropargylic alcohols with 9,10-phenanthrenequinone. The cytotoxicity of newly synthesized compounds was evaluated in CCK8 assay against different human cancer cells, showing significantly antiproliferative activity against tested tumor cell lines with a lowest IC₅₀ value of 0.92 μM over HCT-116. Further investigation revealed that the treatment of HCT-116 cell line with the promising compound 4c induced cell death as a selective Akt inhibitor. In addition, controlled experiments and molecular docking study suggested that the significant antitumor activity might be attributed to the unique hybrid structure, which implied the promising potential of this dual heterocycle hybrid method in the discovery of novel bioactive molecules with structural diversity.

Research Status and Hotspots of Anticancer Natural Products Based on the Patent Literature and Scientific Articles

Background: The patent literature contains a large amount of information on the internal state of current industrial technologies that are not available in other literature studies. Scientific articles are the direct achievements of theoretical research in this field and can reveal how current theories in basic research have developed. In this study, the progress and status of natural anticancer products in this field were summarized, and the research hotspots were explored through the analysis of the relevant patent literature and scientific articles. Methods: Patent data were retrieved from the incoPat patent retrieval database, and paper data were retrieved from the Web of Science core set and PubMed. GraphPad Prism 8, Microsoft Excel 2010, and CiteSpace 5.8.R3 were used to perform visual processing. The analyzed patent literature includes the patent applicant type, country (or region), and technical subject. The analyzed scientific article includes academic groups, subject areas, keyword clustering, and burst detection. Results: A total of 20,435 patent families and 38,746 articles were collected by 4 January 2022. At present, antitumor drugs derived from natural products mainly include 1) apoptosis inducers such as curcumin, gallic acid, resveratrol, Theranekron D6, and gaillardin; 2) topoisomerase inhibitors such as camptothecins, scaffold-hopped flavones, podophyllotoxin, oxocrebanine, and evodiamine derivatives; 3) telomerase inhibitors such as camptothecin and isoquinoline alkaloids of Chelidonium majus, amentoflavone, and emodin; 4) microtubule inhibitors such as kolaflavanone, tanshinone IIA analog, eugenol, and millepachine; 5) immunomodulators such as fucoidan, myricetin, bergapten, and atractylenolide I; 6) tumor microenvironment regulators such as beta-escin and icaritin; 7) multidrug resistance reversal agents such as berberine, quercetin, and dihydromyricetin; and 8) antiangiogenic and antimetastatic agents such as epigallocatechin-3-gallate, lupeol, ononin, and saikosaponin A. Conclusion: Anticancer natural product technology was introduced earlier, but the later development momentum was insufficient. In addition, scientific research activities are relatively closed, and technical exchanges need to be strengthened. Currently, the development of medicinal plants and the research on the anticancer mechanism of natural active products are still research hotspots, especially those related to immune checkpoints, essential oils, and metastatic cancer. Theories of traditional Chinese medicine (TCM), such as "restraining excessiveness to acquire harmony," "same treatment for different diseases," "Meridian induction theory," and "Fuzheng Quxie," have important guiding significance to the research of anticancer mechanisms and the development of new drugs and can provide new ideas for this process. Systematic Review Registration: [https://sourceforge.net/projects/citespace/], identifier [000755430500001].

Camptothecin Delivery via Tumor-Derived Exosome for Radiosensitization by Cell Cycle Regulation on Patient-Derived Xenograft Mice

Purpose: While radiotherapy remains the leading clinical treatment for many tumors, its efficacy can be significantly hampered by the insensitivity of cells in the S phase of the cell cycle to such irradiation.

Methods: Here, we designed a highly targeted drug delivery platform in which exosomes were loaded with the FDA-approved anti-tumor drug camptothecin (CPT) which is capable of regulating cell cycle. The utilized exosomes were isolated from patient tumors, enabling the personalized treatment of individuals to ensure better therapeutic outcomes.

Results: This exosome-mediated delivery strategy was exhibited robust targeted to patient-derived tumor cells in vitro and in established patient-derived xenograft models. By delivering CPT to tumor cells, this nanoplatform was able to decrease cell cycle arrest in the S phase, increasing the frequency of cells in the G1 and G2/M phases such that they were more radiosensitive.

Conclusion: This therapeutic approach was able to substantially enhance the sensitivity of patient-derived tumors to ionizing radiation, thereby improving the overall efficacy of radiotherapy without the need for a higher radiation dose.

Hypoxia Alleviating PdTe Nanoenzymes for Thermoradiotherapy

Hypoxia in the tumor microenvironment induces radioresistance in cancer cells, which reduces the treatment efficiency of radiotherapy. Therefore, it is critical to produce sufficient oxygen to alleviate hypoxia to enhance the effect of ionizing radiation. Here, we constructed nanorod-shaped PdTe nanoenzymes to overcome hypoxia and promote the effects of thermoradiotherapy. Both palladium and tellurium are high-Z elements, which interacted with X-rays to generate more DNA radicals in the tumor regions. Moreover, PdTe nanoenzyme could catalyze the conversion of intratumoral overexpressed H₂O₂ to oxygen, alleviating hypoxia in the tumor regions. Photothermal therapy mediated by PdTe nanoenzymes not only ablated tumors but also accelerated the blood flow, in turn, modulating hypoxia. With good biocompatibility, PdTe nanoenzyme exhibited remarkable oxygen generation ability both in vitro and in vivo, indicating potential ability for radiosensitization. Further investigation using MBT-2 cells and MBT-2 tumor-bearing mice demonstrated that PdTe nanoenzyme could effectively enhance the treatment efficiency of radiotherapy. Thus, our work presented a novel nanoenzyme to overcome hypoxia in tumors for effective thermoradiotherapy.

Effective Combination of Isoniazid and Core-Shell Magnetic Nanoradiotherapy Against Gastrointestinal Tumor Cell Types

Introduction

Radiotherapy is a conventional treatment for gastrointestinal tumors. However, its therapeutic effect might not be satisfactory because of factors such as radio-resistance of tumor cells and dose reduction applied to avoid damage to normal tissues. We developed a novel combination therapy involving the use of isoniazid (INH) and core-shell magnetic nanospheres (NPs) to enhance the efficacy of radiotherapy.

Methods

Magnetic core-shell NPs were synthesized. The shell manganese dioxide (MnO₂) reacted with intracellular glutathione to produce Mn²⁺, which decomposed hydrogen peroxide (H₂O₂) to hydroxyl radicals (·OH) in the presence of INH to produce sufficient amount of reactive oxygen species. In addition to this chemodynamic therapy, MnO₂ catalyzed H₂O₂ to O₂, which alleviated hypoxia in tumors and thus enhanced the effect of radiotherapy. In addition, iron oxide (Fe₃O₄) and reduced Mn²⁺ were potential candidates for T₁–T₂ dual-mode magnetic resonance imaging (MRI) with remarkable magnetic targeting ability.

Results

NPs exhibited efficient tumor targeting performance under the magnetic field and improved T₁/T₂ dual-mode MRI, which elevated oxygen levels without toxicity to the mice to achieve remarkable therapeutic outcomes, reaching a tumor inhibition rate of 93.2%. Moreover, chemodynamic therapy mediated by INH and NPs enhanced the therapeutic effect of radiotherapy both in vivo and in vitro.

Conclusion

The results demonstrated that the combination of INH and NPs could be a novel strategy for radiosensitization with clinical potential.

Development of nanotechnology-mediated precision radiotherapy for anti-metastasis and radioprotection

Radiotherapy (RT), including external beam RT and internal radiation therapy, uses high-energy ionizing radiation to kill tumor cells.

Scintillator-based radiocatalytic superoxide radical production for long-term tumor DNA damage

Photocatalytic materials absorb photons ranging from ultraviolet to near-infrared light to initiate photocatalytic reactions and have broad application prospects in various fields. However, high-energy ionizing radiations are rarely involved in...

Tumor-derived biomimetic nanozyme with immune evasion ability for synergistically enhanced low dose radiotherapy

High doses of radiation can cause serious side effects and efficient radiosensitizers are urgently needed. To overcome this problem, we developed a biomimetic nanozyme system (CF) by coating pyrite (FeS2) into tumor-derived exosomes for enhanced low-dose radiotherapy (RT). CF system give FeS2 with immune escape and homologous targeting abilities. After administration, CF with both glutathione oxidase (GSH-OXD) and peroxidase (POD) activities can significantly lower the content of GSH in tumor tissues and catalyze intracellular hydrogen peroxide (H2O2) to produce a large amount of ·OH for intracellular redox homeostasis disruption and mitochondria destruction, thus reducing RT resistance. Experiments in vivo and in vitro showed that combining CF with RT (2 Gy) can provide a substantial suppression of tumor proliferation. This is the first attempt to use exosomes bionic FeS2 nanozyme for realizing low-dose RT, which broaden the prospects of nanozymes.

Platelet Membranes Coated Gold Nanocages for Tumor Targeted Drug Delivery and Amplificated Low-Dose Radiotherapy

Continuous high doses of radiation can cause irreversible side effects and radiation resistance; thus, advanced radiosensitizers are urgently needed. To overcome this problem, we developed a nano platelet radiosensitization system (PCA) by coating the chemotherapeutic drug cisplatin (CDDP) loaded gold nanocages (AuNs) within the platelet membrane. The developed PCA system may enable AuNs to have immune escape and targeting capabilities. After administration, PCA will actively target tumor cells and avoid being cleared by the immune system. Subsequently, CDDP, which destroys tumor cell DNA, can not only kill tumor cells directly but also combine with AuNs, which deposit radiation energy into tumor tissues, reducing RT resistance. In vivo and in vitro studies revealed that the combination of PCA with RT (2Gy) efficiently inhibits tumor proliferation without causing side effects such as inflammation. To conclude, this is the first attempt to use platelet membranes to correctly transport AuNs while also accomplishing low-dose RT, which could help AuNs-based tumor RT become more effective.

131I-Labeled gold nanoframeworks for radiotherapy-combined second near-infrared photothermal therapy of cancer

Photothermal therapy (PTT) has shown great promise for cancer treatment via light-triggered heat generation, while the anticancer efficacy of sole PTT is often limited. In this study, we report the use of radionuclide ¹³¹I-labeled gold nanoframeworks (¹³¹I-AuNFs) for radiotherapy-combined second near-infrared (NIR-II) PTT of breast cancer. AuNFs synthesized via a simple reduction approach are surface functionalized with polydopamine and poly(ethylene glycol), followed by labeling with ¹³¹I. The formed ¹³¹I-AuNFs with a high photothermal conversion efficacy and stable radioactivity can effectively accumulate into subcutaneous 4T1 mouse models as confirmed by in vivo single photon emission computed tomography (SPECT) imaging. Upon 1064 nm laser irradiation of tumors, local heat is generated for NIR-II PTT, which combines with radiotherapy to achieve a much higher therapeutic efficacy relative to sole treatment. As such, ¹³¹I-AuNFs-mediated radiotherapy-combined NIR-II PTT results in the effective inhibition of the growth of subcutaneous tumors. This study thus provides a facile nanoplatform for effective combination cancer therapy.

SnFe2O4 Nanozyme Based TME Improvement System for Anti-Cancer Combination Thermoradiotherapy

High doses of radiotherapy (RT) are associated with resistance induction. Therefore, highly selective and controllable radiosensitizers are urgently needed. To address this issue, we developed a tin ferrite (SFO)-based tumor microenvironment (TME)-improved system (SIS) that can be used in combination with low-dose radiation. The SIS was delivered via intratumoral injection directly to the tumor site, where it was stored as a ration depot. Due to the photothermal properties of SFO, SIS steadily dissolved under near-infrared (NIR) laser irradiation. Simultaneously, the dual glutathione oxidase (GSH-OXD) and catalase (CAT) activities of the SFO nanozyme significantly lowered the content of GSH in tumor tissues and efficiently catalyzed the conversion of intracellular hydrogen peroxide to produce a large amount of oxygen (O₂) for intracellular redox homeostasis disruption, thus reducing radiotherapy resistance. Our in vivo and in vitro studies suggested that combining the SIS and NIR irradiation with RT (2Gy) significantly reduced tumor proliferation without side effects such as inflammation. To conclude, this study revealed that SFO-based nanozymes show great promise as a catalytic, radiosensitizing anti-tumor therapy.

Traditional herbal medicine and nanomedicine: Converging disciplines to improve therapeutic efficacy and human health

Traditional herbal medicine (THM), an ancient science, is a gift from nature. For thousands of years, it has helped humans fight diseases and protect life, health, and reproduction. Nanomedicine, a newer discipline has evolved from exploitation of the unique nanoscale morphology and is widely used in diagnosis, imaging, drug delivery, and other biomedical fields. Although THM and nanomedicine differ greatly in time span and discipline dimensions, they are closely related and are even evolving toward integration and convergence. This review begins with the history and latest research progress of THM and nanomedicine, expounding their respective developmental trajectory. It then discusses the overlapping connectivity and relevance of the two fields, including nanoaggregates generated in herbal medicine decoctions, the application of nanotechnology in the delivery and treatment of natural active ingredients, and the influence of physiological regulatory capability of THM on the in vivo fate of nanoparticles. Finally, future development trends, challenges, and research directions are discussed.

An Injectable Hydrogel for Enhanced FeGA-Based Chemodynamic Therapy by Increasing Intracellular Acidity

Hydroxyl radical (•OH)-mediated chemodynamic therapy (CDT) is an emerging antitumor strategy, however, acid deficiency in the tumor microenvironment (TME) hampers its efficacy. In this study, a new injectable hydrogel was developed as an acid-enhanced CDT system (AES) for improving tumor therapy. The AES contains iron-gallic acid nanoparticles (FeGA) and α-cyano-4-hydroxycinnamic acid (α-CHCA). FeGA converts near-infrared laser into heat, which results in agarose degradation and consequent α-CHCA release. Then, as a monocarboxylic acid transporter inhibitor, α-CHCA can raise the acidity in TME, thus contributing to an increase in ·OH-production in FeGA-based CDT. This approach was found effective for killing tumor cells both in vitro and in vivo, demonstrating good therapeutic efficacy. In vivo investigations also revealed that AES had outstanding biocompatibility and stability. This is the first study to improve FeGA-based CDT by increasing intracellular acidity. The AES system developed here opens new opportunities for effective tumor treatment.

MicroRNA-29b regulates the radiosensitivity of esophageal squamous cell carcinoma by regulating the BTG2-mediated cell cycle

BACKGROUND

Many patients with esophageal squamous cell carcinoma (ESCC) are inoperable due to old age or advanced stage; thus, radio- and chemotherapy are considered the standard treatments for these patients. However, due to the radiation resistance of tumor cells that may arise during radiotherapy, results are still not satisfactory. The authors' previous studies found that microRNA can affect radiosensitivity, and further microRNA research was conducted to improve the radiosensitivity of ESCC.

METHODS

Cells were treated with silent miR-29b (si-miR-29b). Thereafter,proliferation, colony formation, cell cycle, and apoptosis were determined. The luciferase reporting assay was used to confirm the direct interaction between miR-29b and BTG2. Serum samples and clinical follow-up data of 75 elderly or advanced ESCC patients who could not tolerate surgery were collected.

RESULTS

The expression level of miR-29 in ESCC serum was closely correlated to radiosensitivity (χ² =8.36, p < 0.05) and correlated with overall survival (OS; hazard ratio [HR] 0.47, 95% confidence interval [CI] 0.24-0.90). Function assays demonstrated that the number of cell clones increased after radiometry radiation, and the cell cycle was blocked in the G0/G1 phase (from 37.2 to 56.9%) in the si-miR-29b transfection group. Expression of BTG2 was upregulated and expression of cyclin D1 was downregulated (p < 0.05). Transfection of si-BTG2 can reverse this result and restore the expression level of cyclin D1 (p < 0.05). The target gene BTG2 of miR-29b was predicted using a bioinformatics tool and confirmed by dual-luciferase reporter assay.

CONCLUSION

Silencing of miR-29b in ESCC cells can increase expression of BTG2 and decrease the level of intracellular cyclin D1, resulting in cell cycle arrest and accumulation in the G0/G1 phase. Because G0/G1-phase cells are insensitive to radiotherapy, the sensitivity of radiotherapy is reduced.

Artesunate-loaded poly (lactic-co-glycolic acid)/polydopamine-manganese oxides nanoparticles as an oxidase mimic for tumor chemo-catalytic therapy

Conventional tumor chemotherapy is limited by its low therapeutic efficacy and side effects, which severely hold back its further application as a first-line agent in clinic. To improve the cure efficacy of cancer, nanozyme with enzyme-like activity has now been extensively investigated as a new strategy for tumor treatment. Herein, an anti-tumor platform based on manganese oxides (MnOx) modified poly (lactic-co-glycolic acid) (PLGA)@polydopamine (PDA) nanoparticles (PP-MnOx NPs) as an oxidase mimic was developed. PP-MnOx NPs could not only produce abundant reactive oxygen species to inhibit tumor growth taking advantage of their oxidase-like activity, but also encapsulate and release antitumor drug (artesunate) to function as chemotherapy, achieving remarkable synergistic chemo-catalytic therapeutic effects. As an oxidase mimics, PP-MnOx NPs induced the decrease of mitochondrial membrane potential, down-regulation of Bcl-2, as well as activation of Bax and Caspase-3, demonstrating that the apoptosis triggered by PP-MnOx NPs was mediated via mitochondrial pathways. Importantly, the artesunate in PP-MnOx NPs further promoted this apoptosis. In addition, Mn ions released from PP-MnOx NPs facilitated the tumor-microenvironment-specific T1-weighted magnetic resonance imaging. Taken together, this study well clarifies the antitumor mechanism of artesunate-loaded PP-MnOx NPs and offer a synergistic chemo-catalytic strategy for tumor theranostics.

A Homotypic Membrane-Camouflaged Biomimetic Nanoplatform with Gold Nanocrystals for Synergistic Photothermal/Starvation/Immunotherapy

Although photothermal therapy (PTT) has great potential for tumor inhibition, this single mode of action frequently encounters recurrence and metastasis, highlighting the urgent need for developing combination therapy. Inspired by established evidence that PTT could induce efficient immunogenic cell death (ICD), we here developed a versatile biomimetic nanoplatform (denoted as AuDRM) for the synergism of photothermal/starvation/immunotherapy against cancer. Specifically, dendritic mesoporous silica nanoparticles (NPs) were successfully constructed followed by the in situ synthesis of Au NPs in the mesopores. Afterward, a hybrid membrane was coated to facilitate the loading of R837. Upon efficient accumulation in the tumor tissue by homotypic targeting, the pH-sensitive membrane could be jettisoned to ensure the exposure of Au NPs for starvation therapy and the effective release of the immunostimulator R837 for enhancement of immunotherapy. Except for the PTT-mediated tumor ablation, the induction of ICD coupled with the release of tumor antigens could work synergistically with the immunostimulator R837 for inhibiting the primary tumor as well as the metastasis and induce a long-term immune memory effect for tumor inhibition via a vaccine-like function. Thus, this study paves the way for high-performance tumor ablation by the synergism of photothermal/starvation/immunotherapy.

Iron-Palladium Decorated Carbon Nanotubes Achieve Radiosensitization via Reactive Oxygen Species Burst

Radiotherapy is recommended as a modality for cancer treatment in clinic. However, cancerous cells were resistant to therapeutic irradiation due to its DNA repair. In this work, single-walled carbon nanotubes with unique physical properties of hollow structures and high specific surface area were introduced as carrier for iron-palladium (FePd) to obtain iron-palladium decorated carbon nanotubes (FePd@CNTs). On one hand, FePd nanoparticles possess significant ability in radiosensitization as previously reported. On the other hand, carbon nanotubes offer higher efficiency in crossing biological barriers, inducing the accumulation and retention of FePd nanoparticles within tumor tissue. In order to verify the radiosensitization effect of FePd@CNTs, both in vitro and in vivo experiments were conducted. These experiments showed that the FePd@CNTs exhibited remarkably better radiosensitization effect and more obvious accumulation than FePd NPs, suggesting a potential of FePd@CNTs in radiosensitization.

Delivery of manganese carbonyl to the tumor microenvironment using Tumor-Derived exosomes for cancer gas therapy and low dose radiotherapy

The development of novel radiosensitizer with high selectivity and controllability is highly desirable. CO gas could cause damage to mitochondria and thus enhance RT effect. Controlled delivery of CO in tumor is important both to achieve high-efficiency of CO gas therapy and to decrease the risk of CO poisoning. In this study, manganese carbonyl (MnCO) loaded exosome nano-vesicles (MMV) to overcome this conundrum for tumor therapy is developed. After administration, MMV showed its admirable performance in active tumor-targeting, mitochondria damage and radiosensitization therapy. These MMV nanoparticles were able to facilitate robust CO evolution and consequent ROS generation in response to X-ray irradiation both in vitro and in vivo. Significantly, MMV could facilitate a 90% inhibition effect of tumor growth under very low dose (only 2Gy) RT, which is better than high dose (6Gy) radiotherapy. Overall, this study highlights a novel and practical approach to enhancing the efficacy of tumor RT, underscoring the value of future research in the field of CO medicine.

Injectable Hydrogel for Cu2+ Controlled Release and Potent Tumor Therapy

Disulfiram (DSF) is an important drug for the treatment and management of alcohol dependency. This drug has been approved by US-FDA, and its activity against the tumor is dependent on copper ion (Cu²⁺). However, the copper toxicity (caused via external copper) and its intrinsic anfractuous distribution in the human body have adversely suppressed the mechanism of DSF in in vivo. In this study, we aimed to design an injectable hydrogel, as CRC (Cu²⁺ release controller) for the effective treatment of tumors. The hydrogels of agarose have been used for wrapping of CuCl₂, and hierarchical microparticles (HMP) for the generation of CRC system. When the laser irradiations (808 nm) have been provided to the system, light energy is transferred into heat energy, which results in the hydrogel hydrolysis (reversible) due to the overheating effect. This is followed by a reaction with DSF (pre-injected) to suppress tumor progression. Hence, the CRC system brings innovative ideas for designing of a Cu²⁺ delivery system.

Application of New Radiosensitizer Based on Nano-Biotechnology in the Treatment of Glioma

Glioma is the most common intracranial malignant tumor, and its specific pathogenesis has been unclear, which has always been an unresolved clinical problem due to the limited therapeutic window of glioma. As we all know, surgical resection, chemotherapy, and radiotherapy are the main treatment methods for glioma. With the development of clinical trials and traditional treatment techniques, radiotherapy for glioma has increasingly exposed defects in the treatment effect. In order to improve the bottleneck of radiotherapy for glioma, people have done a lot of work; among this, nano-radiosensitizers have offered a novel and potential treatment method. Compared with conventional radiotherapy, nanotechnology can overcome the blood–brain barrier and improve the sensitivity of glioma to radiotherapy. This paper focuses on the research progress of nano-radiosensitizers in radiotherapy for glioma.

Multifunctional titanium phosphate carriers for enhancing drug delivery and evaluating real-time therapeutic efficacy of a hydrophobic drug component in Euphorbia kansui

Nanoparticles are often used to serve as drug delivery systems to improve the therapeutic efficacy of some hydrophobic drugs. In this work, PEG and peptide-modified titanium phosphate nanoparticles (TiP-PEG/peptide) were synthesized to enhance the drug delivery efficacy of tirucalla-8,24-diene-3β,11β-diol-7-one (KS-01), a major bioactive and hydrophobic component extracted from Euphorbia kansui. This drug delivery system with a loading efficiency of about 29.8 mg KS-01/1 g TiP-PEG/peptide exerted a significantly lower cell viability rate of MCF-7 than free KS-01, indicating that these carriers can effectively increase the therapeutic efficacy by improving its water solubility. Moreover, according to the fluorescence intensity of FAM which can be generated by caspase-3 cleaving DEVD-embedded peptide, the caspase-3 level could be determined and the therapeutic efficacy could be visualized in real time.

Glutathione-depleting nanoplatelets for enhanced sonodynamic cancer therapy

In combating cancer, ultrasound (US)-triggered sonodynamic therapy (SDT) manifests a wide range of promising applications as a noninvasive treatment modality, thus showing potential to overcome the shortcomings and disadvantages of conventional photodynamic therapy (PDT). Reactive oxygen species (ROS)-based therapy is practically destroyed by the high concentration of glutathione (GSH) inside tumors, and depleting GSH to improve the outcome of SDT is indeed a great challenge. Herein, we designed GSH-depleting nanoplatelets for enhanced sonodynamic cancer therapy. A platelet membrane coated nanosystem (PSCI) has been designed and tested comprising mesoporous silica nanoparticles (MSNs) which have been loaded with cinnamaldehyde (CA) as an oxidative stress amplifier. The inner layer comprises the sonosensitizer IR780 and the oxidative stress amplifier CA, whereas the platelet membranes (PM) were designed and utilized as an outer layer that can target tumors, thereby enhancing the effectiveness of SDT by attenuating the capability of tumor cells for scavenging ROS with GSH. SDT and cinnamaldehyde amplify oxidative stress by acting synergistically, leading to the preferential destruction of cancer cells in vitro and in vivo. It is hoped that next-generation tumor SDT treatments will find their way with the help of this strategy.

Development of a novel oxidative stress-amplifying nanocomposite capable of supplying intratumoral H2O2 and O2 for enhanced chemodynamic therapy and radiotherapy in patient-derived xenograft (PDX) models

Radiotherapy (RT) is a potent approach to cancer treatment, but the tumor microenvironment (TME) in solid tumors is often highly hypoxic and contains high levels of antioxidant enzymes, thereby reducing the RT efficacy. In this study, we developed an oxidative stress amplifier (termed CFM) capable of self-sufficient H2O2 and O2 delivery that can be used in concert with RT and chemodynamic therapy (CDT) to treat tumors in patient-derived xenograft (PDX) model systems. Upon exposure to the hypoxic and acidic TME, CFM undergoes rapid degradation that results in the release of Fe3+, Ca2+, O2, and H2O2. Glutathione can subsequently reduce Fe3+ to Fe2+, which is then able to react with H2O2via the Fenton reaction to yield high levels of hydroxyl radicals which subsequently damage mitochondria. CaO2-derived O2 also modulates intratumoral hypoxia, while excessive Ca2+ levels within mitochondria result in apoptotic cell death. Altogether, these properties sensitize PDX tumors to RT. Importantly, the Fe, Zn, and Ca generated by CFM degradation are essential elements in humans. Altogether, these properties make this approach to oxidative stress amplification a promising means of amplifying oxidative stress within tumors while overcoming hypoxia-related resistance to RT, thereby providing a framework for the design of potent radiosensitizing therapeutic approaches.

Design, synthesis and screening of benzimidazole containing compounds with methoxylated aryl radicals as cytotoxic molecules on (HCT-116) colon cancer cells

A novel series of benzimidazole derivatives with methoxylated aryl groups was designed and synthesized as molecules with potential cytotoxic activity. In vitro cytotoxic activity over HCT-116 cells showed that N-(benzimidazothiazolone)acetamides 11a, 11b and 11c were found to be the most cytotoxic compounds compared camptothecin (CPT). The tested compounds had a dual topoisomerase I-β (Topo I-β) and tubulin inhibiting activities when compared to CPT and Podophyllotoxin (Podo) where, compounds l0a, l0b, 11a and 11b exhibited a potent inhibitory activity on Topo I-β enzyme in nano-molar concentration, on the other hand, compounds 12b and 13b exhibited the best inhibitory activity β-tubulin polymerization. Results of the cell cycle analysis as well as the results of annexin-V on HCT-116 cells showed that benzimidazothiazoles 12b and 13b had a pro-apoptotic activity higher than CPT by 1.33- and 1.30-folds, respectively. Moreover, the concentration of p53, Bax/Bcl-2 ratio and caspase 3/7 increased in compounds l0b, 11b, l2b, 13b, especially, compounds 11b and 13b exhibited an increased level of these mediators than CPT. Finally, compound 11b regulated the radiosensitizing activity of the HCT-116 cells by modulating the chromosomal instability.

Stellate Plasmonic Exosomes for Penetrative Targeting Tumor NIR-II Thermo-Radiotherapy

Multifunctional gold (Au)-based nanomaterials with high atomic number (symbol Z) and strong absorbance in the second near-infrared window (NIR-II) property are emerging as promising candidates for tumor thermo-radiotherapy. The main limitations of applying Au-based nanomaterials to biomedical studies include the absence of active tumor-targeting ability, penetrating efficiency, and stability. In this study, we present a novel type of tumor cell-derived stellate plasmonic exosomes (TDSP-Exos) for penetrative targeted tumor NIR-II thermo-radiotherapy and photoacoustic imaging. The TDSP-Exos are abundantly and easily produced by the incubation of tumor cells with gold nanostars, based on which gold nanostars promote the exocytosis of exosomes from tumor cells. Compared with bare gold nanostars, the TDSP-Exos exhibit pronounced accumulation in deep tumor tissues and perform well in both PA imaging and NIR-II thermo-radiotherapy against the tumor. Moreover, the TDSP-Exos improve tumor hypoxia to enhanced radiotherapy by NIR-II photothermal therapy. This work indicates that the tumor cell-derived exosomes have the potential to function as a universal carrier of photothermal agents for targeted tumor NIR-II thermo-radiotherapy.