Radiation-enhancing effect of sodium glycididazole in patients suffering from non-small cell lung cancer with multiple brain metastases: A randomized, placebo-controlled study

Nanomedicine Combats Drug Resistance in Lung Cancer

Lung cancer is the second most prevalent cancer and the leading cause of cancer-related death worldwide. Surgery, chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy are currently available as treatment methods. However, drug resistance is a significant factor in the failure of lung cancer treatments. Novel therapeutics have been exploited to address complicated resistance mechanisms of lung cancer and the advancement of nanomedicine is extremely promising in terms of overcoming drug resistance. Nanomedicine equipped with multifunctional and tunable physiochemical properties in alignment with tumor genetic profiles can achieve precise, safe, and effective treatment while minimizing or eradicating drug resistance in cancer. Here, this work reviews the discovered resistance mechanisms for lung cancer chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy, and outlines novel strategies for the development of nanomedicine against drug resistance. This work focuses on engineering design, customized delivery, current challenges, and clinical translation of nanomedicine in the application of resistant lung cancer.

Biotin-decorated hollow gold nanoshells for dual-modal imaging-guided NIR-II photothermal and radiosensitizing therapy toward breast cancer

Radiotherapy (RT) is dominantly used in breast cancer therapy but is facing fierce side effects because of the limited difference between tumor and normal tissues in response to ionizing radiation. Herein, we construct a core-shell nanoparticle of UiO-66-NH2@AuNS. Then the solid gold shell was etched into hollow AuNS (HAuNS) and further modified with biotin-PEG-SH (PEG-bio) to obtain HAuNS@PEG-bio. HAuNS@PEG-bio demonstrates effective near infrared II (NIR-II) region photothermal therapy (PTT) performance, and the increase of temperature at the tumor site promotes the blood circulation to alleviate the hypoxia in the tumor microenvironment (TME). Meanwhile, HAuNS exhibits strong X-ray absorption and deposition ability due to the high atomic coefficient of elemental Au (Z = 79) and hollowed-out structure. Through the dual radiosensitization of the high atomic coefficient of Au and the hypoxia alleviation from PTT of HAuNS, the breast cancer cells could undergo immunogenic cell death (ICD) to activate the immune response. At the in vivo level, HAuNS@PEG-bio performs NIR-II photothermal, radiosensitization, and ICD therapies through cellular targeting, guided by infrared heat and CT imaging. This work highlights that the constructed biotin-decorated hollow gold nanoshell has a promising potential as a diagnostic and treatment integration reagents for the breast cancer.

Ketoglutaric acid can reprogram the immunophenotype of triple-negative breast cancer after radiotherapy and improve the therapeutic effect of anti-PD-L1

BACKGROUND

Great progress has been made in applying immunotherapy to the clinical treatment of tumors. However, many patients with triple-negative breast cancer (TNBC) cannot benefit from immunotherapy due to the immune desert type of TNBC, which is unresponsive to immunotherapy. DMKG, a cell-permeable derivative of α-KG, has shown potential to address this issue.

METHOD

We investigated the effects of combining DMKG with radioimmunotherapy on TNBC. We assessed the ability of DMKG to promote tumor cell apoptosis and immunogenic death induced by radiotherapy (RT), as well as its impact on autophagy reduction, antigen and inflammatory factor release, DC cell activation, and infiltration of immune cells in the tumor area.

RESULT

Our findings indicated that DMKG significantly promoted tumor cell apoptosis and immunogenic death induced by RT. DMKG also significantly reduced autophagy in tumor cells, resulting in increased release of antigens and inflammatory factors, thereby activating DC cells. Furthermore, DMKG promoted infiltration of CD8 + T cells in the tumor area and reduced the composition of T-regulatory cells after RT, reshaping the tumor immune microenvironment. Both DMKG and RT increased the expression of PD-L1 at immune checkpoints. When combined with anti-PD-L1 drugs (α-PD-L1), they significantly inhibited tumor growth without causing obvious side effects during treatment.

CONCLUSION

Our study underscores the potential of pairing DMKG with radioimmunotherapy as an effective strategy for treating TNBC by promoting apoptosis, immunogenic death, and remodeling the tumor immune microenvironment. This combination therapy could offer a promising therapeutic avenue for TNBC patients unresponsive to conventional immunotherapy.

Vascular bursts-mediated tumor accumulation and deep penetration of spherical nucleic acids for synergistic radio-immunotherapy

While nanomedicines have attracted great interests for tumor therapy, their targeting and intra-tumoral penetrating efficiencies have been questioned. Here, we report a two-step low-dose radiotherapy (RT) strategy to realize significant accumulation and deep penetration of spherical nucleic acids (SNAs)-based nanomedicine for synergistic radio-immunotherapy. The first step RT was employed to recruit large amounts of macrophages into tumor. The tumor infiltrated macrophages not only served as nanoparticles drug depots, but also elicited dynamic bursts extravasation to enhance nanoparticles accumulation. We optimized the spatiotemporal combination of RT and SNAs administration for higher level of SNAs delivery, and the delivered SNAs promote M2-to-M1 phenotype switch of macrophages to increase phagocytosis of nanoparticles by 6-fold, resulting in positive feedback with even higher accumulation and intra-tumor penetration of SNAs. Through vascular bursts and macrophage repolarization, as high as 25-fold enhancement of nanoparticles accumulation was achieved as compared to passive targeting of nanoparticles, and the nanoparticles were eventually distributed throughout the tumor tissue with efficient deep penetration. Finally, SNAs in tumor simultaneously sensitized the second dose of RT and remodeled tumor immune microenvironment, resulting in a synergistic anticancer therapy in combination of anti-PD-L1 antibody (αPD-L1) with no noticeable side effects caused by either RT or αPD-L1.

Comparative Efficacy of Treatments for Brain Metastases from Non-Small Cell Lung Cancer without an EGFR-Mutation/ALK-Rearrangement: A Systematic Review and Network Meta-Analysis

INTRODUCTION

As many as 30% of patients with non-small cell lung cancer (NSCLC) will develop brain metastases (BMs) over the course of their illness. Here, we quantitatively compare the efficacy of the various emerging regimens for NSCLC BMs without a definitive targetable epidermal growth factor receptor mutation/ALK rearrangement.

METHODS

We searched MEDLINE, EMBASE, Web of Science, ClinicalTrials.gov, CENTRAL, and references of key studies for randomized controlled trials (RCTs) published from inception until June 2020. Comparative RCTs that included ≥10 patients were included. We used a frequentist fixed or random-effects model for network meta-analysis. The outcomes of interest included intracranial progression-free survival (iPFS), overall survival (OS), and overall progression-free survival.

RESULTS

In total, 18 studies representing 17 trials (n = 2726 patients) were identified. Immune checkpoint inhibitor regimens showed significant improvement in OS compared with chemotherapy alone, including pembrolizumab and chemotherapy (6 studies, hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.21-0.62), atezolizumab alone (HR 0.54, 95% CI 0.33-0.89), and nivolumab and ipilimumab (HR 0.64, 95% CI 0.42-0.97). An improvement in overall PFS was seen with use of pembrolizumab and chemotherapy compared with chemotherapy alone (3 studies, HR 0.42, 95% CI 0.26-0.68). Studies evaluating checkpoint inhibitors did not report iPFS data, and we did not find improvement in iPFS or OS with the addition of any chemotherapy regimen to whole-brain radiation therapy.

CONCLUSIONS

In this network meta-analysis, we demonstrate the promising survival benefit with use of checkpoint inhibitor-based regimens in NSCLC BMs without a targetable epidermal growth factor receptor mutation/ALK rearrangement. Moving forward, large-scale BM-focused RCTs are necessary to establish the iPFS benefit of immune checkpoint inhibitor-based immunotherapy in this patient population.

Radiation Therapy for Brain Metastases: A Systematic Review

PURPOSE

This evidence report synthesizes the available evidence on radiation therapy for brain metastases.

METHODS AND MATERIALS

The literature search included PubMed, EMBASE, Web of Science, Scopus, CINAHL, clinicaltrials.gov, and published guidelines in July 2020; independently submitted data, expert consultation, and contacting authors. Included studies were randomized controlled trials (RCTs) and large observational studies (for safety assessments), evaluating whole brain radiation therapy (WBRT) and stereotactic radiosurgery (SRS) alone or in combination, as initial or postoperative treatment, with or without systemic therapy for adults with brain metastases due to lung cancer, breast cancer, or melanoma.

RESULTS

Ninety-seven studies reported in 189 publications were identified, but the number of analyses was limited owing to different intervention and comparator combinations as well as insufficient reporting of outcome data. Risk of bias varied, and 25 trials were terminated early, predominantly owing to poor accrual. The combination of SRS plus WBRT compared with SRS alone or WBRT alone showed no statistically significant difference in overall survival (hazard ratio [HR], 1.09; 95% confidence interval [CI], 0.69%-1.73%; 4 RCTs) or death owing to brain metastases (relative risk [RR], 0.93; 95% CI, 0.48%-1.81%; 3 RCTs). Radiation therapy after surgery did not improve overall survival compared with surgery alone (HR, 0.98; 95% CI, 0.76%-1.26%; 5 RCTs). Data for quality of life, functional status, and cognitive effects were insufficient to determine effects of WBRT, SRS, or postsurgery interventions. We did not find systematic differences across interventions in serious adverse events, number of adverse events, radiation necrosis, fatigue, or seizures. WBRT plus systemic therapy (RR 1.44; 95% CI, 1.03%-2.00%; 14 studies) was associated with increased risks for vomiting compared with WBRT alone.

CONCLUSIONS

Despite the substantial research literature on radiation therapy, comparative effectiveness information is limited. There is a need for more data on patient-relevant outcomes such as quality of life, functional status, and cognitive effects.

Current Landscape and Future Prospects of Radiation Sensitizers for Malignant Brain Tumors: A Systematic Review

BACKGROUND

Radiation therapy (RT) is the cornerstone of management of malignant brain tumors, but its efficacy is limited in hypoxic tumors. Although numerous radiosensitizer compounds have been developed to enhance the effect of RT, progress has been stagnant. Through this systematic review, we provide an overview of radiosensitizers developed for malignant brain tumors, summarize their safety and efficacy, and evaluate areas for possible improvement.

METHODS

Following PRISMA guidelines, PubMed, EMBASE, Cochrane, and Web of Science were searched using terminology pertaining to radiosensitizers for brain tumor RT. Articles reporting clinical evidence of nonantineoplastic radiosensitizers with RT for malignant central nervous system tumors were included. Data of interest were presumed mechanism of action, median overall survival (OS), progression-free survival (PFS), and adverse events.

RESULTS

Twenty-two unique radiosensitizers were identified. Only 2/22 agents (fluosol with oxygen, and efaproxiral) showed improvement in OS in patients with glioblastoma and brain metastasis, respectively. A larger study was not able to confirm the latter. Improved PFS was reported with use of metronidazole, sodium glycididazole, and chloroquine. There was a wide range of toxicities, which prompted change of schedule or complete discontinuation of 9 agents.

CONCLUSIONS

Progress in radiosensitizers for malignant CNS tumors has been limited. Only 2 radiosensitizers have shown limited improvement in survival. Alternative strategies such as synthetic drug design, based on a mechanism of action that is independent of crossing the blood-brain barrier, may be necessary. Use of drug development strategies using new technologies to overcome past challenges is necessary.

Enhanced radiotherapy using photothermal therapy based on dual-sensitizer of gold nanoparticles with acid-induced aggregation

The damaged DNA strands caused by radiotherapy (RT) can repair by themselves. A gold nanoparticles (GNPs) system with acid-induced aggregation was developed into a dual sensitizer owing to its high radioactive rays attenuation ability and enhanced photothermal heating efficiency after GNPs aggregation to achieve a combination therapy of RT and photothermal therapy (PTT). In this combination therapy, the formed GNP aggregates firstly showed a higher sensitize enhancement ratio (SER) value (1.52). Importantly, the self-repair of damaged DNA strands was inhibited by mild PTT through down-regulating the expression of DNA repair protein, thus resulting in a much higher SER value (1.68). Anti-tumor studies further demonstrated that this combination therapy exhibited ideal anti-tumor efficacy. Furthermore, the imaging signals of GNPs in computed tomography and photoacoustic were significantly improved following the GNPs aggregation. Therefore, a dual sensitizer with multimodal imaging was successfully developed and can be further applied as a new anti-tumor therapy.

Enhanced Radiosensitization by Gold Nanoparticles with Acid-Triggered Aggregation in Cancer Radiotherapy

An ideal radiosensitizer holding an enhanced tumor retention can play an incredible role in enhancing tumor radiotherapy. Herein, a strategy of acid-triggered aggregation of small-sized gold nanoparticles (GNPs) system within tumor is proposed and the resulting GNPs aggregates are applied as a radiosensitizer in vitro and in vivo. The GNPs system with the acid-triggered aggregation achieves an enhanced GNPs accumulation and retention in cancer cells and tumors in the form of the resulted GNPs aggregates. As a consequence, the radiosensitization effect shows significant improvement in cancer radiotherapy, which is shown in the studies of DNA breakage and the comet assay, and the sensitizer enhancement ratio (SER) value of the GNPs system (1.730) with MCF-7 cancer cells is much larger than that of the single GNPs (1.16). In vivo antitumor studies reveal that the GNPs system also enhances the sensitivity of MCF-7 tumor xenograft to radiotherapy. Furthermore, the GNPs aggregates improve the signal of small GNPs in vivo photoacoustic imaging. This study provides a new strategy and insights into fabricating nanoaggregates to magnify the radiosensitive efficiency of nanosystems in cancer radiotherapy.

Hypoxia-responsive block copolymer radiosensitizers as anticancer drug nanocarriers for enhanced chemoradiotherapy of bulky solid tumors

Radiosensitizers play an important role in the clinical radiotherapy of hypoxic solid tumors to improve therapeutic efficacy. However, the in vivo performance of clinically used small-molecule radiosensitizers is commonly compromised by low bioavailability in hypoxic tumor regions. Herein, amphiphilic block copolymer radiosensitizers are prepared from clinically approved poly(ethylene glycol)-block-poly(l-glutamic acid) (PEG-b-PLG) and metronidazole (MN) to obtain MN-grafted PEG-b-PLG (PEG-b-P(LG-g-MN)) via condensation reaction, which can self-assemble into core-shell micelles as nanoparticle-formulated radiosensitizers in aqueous solution. The radiosensitizers are demonstrated to possess significantly higher sensitization enhancement ratio (SER) of 2.18 and potent in vivo tumor ablation capability upon exposure to electron beam irradiation compared with clinically used sodium glycididazole (GS) with SER of 1.32. Moreover, after optimizing the ratios of carboxyl and MN groups, PEG-b-P(LG-g-MN) micelles can be used to encapsulate doxorubicin (DOX@HMs) efficiently. Hypoxia-responsive structural transformation of MN into hydrophilic aminoimidazole triggers fast DOX release from DOX@HMs. After intravenous injection of DOX@HMs, potent ablation capability against bulky solid tumors (∼500 mm³) is realized at a low radiation dose (4 Gy) via enhanced chemoradiotherapy. Therefore, the developed novel amphiphilic block copolymer radiosensitizers can be concurrently used as high-efficiency radiosensitizers and hypoxia-responsive DOX nanocarriers for enhanced chemoradiotherapy.

Preclinical study on hypoxic radiosensitizing effects of glycididazole in comparison with those of doranidazole in vitro and in vivo

To overcome the radioresistance of hypoxic cells in solid tumor, numerous types of radiosensitizers specifically against them have been developed. Glycididazole has a chemical structure in which two metronidazole forms are combined, and is widely used as a hypoxic radiosensitizer in China. However, a detailed investigation of its radiosensitizing properties has not been performed. The present study reported a comparative assessment of glycididazole and doranidazole, another hypoxic radiosensitizer. All experiments were performed using the murine squamous cell carcinoma cell line SCCVII. Prior to X-irradiation, the cells were treated with the test drugs at concentrations of 10 mM and 200 mg/kg in vitro and in vivo, respectively. Uptake and their intratumor chemical forms were analyzed by high performance liquid chromatography (HPLC). Both drugs enhanced the reproductive cell death induced by X-irradiation under hypoxia. However, the growth delay assay of the transplanted tumor revealed the combination of X-irradiation and glycididazole showed a similar antitumor effect to that of X-irradiation alone, whereas doranidazole significantly sensitized the cells to X-irradiation. HPLC analysis revealed that incorporated glycididazole was decomposed to metronidazole and was therefore present at a lower concentration compared with that of doranidazole. The decomposition of glycididazole to metronidazole reduced its radiosensitizing efficiency in vivo. Elucidation of the kinetics of drugs containing metabolizable chemical forms is necessary for the optimization of clinical treatment.

Whole brain radiotherapy for the treatment of newly diagnosed multiple brain metastases

BACKGROUND

This is an update to the review published in the Cochrane Library (2012, Issue 4).It is estimated that 20% to 40% of people with cancer will develop brain metastases during the course of their illness. The burden of brain metastases impacts quality and length of survival.

OBJECTIVES

To assess the effectiveness and adverse effects of whole brain radiotherapy (WBRT) given alone or in combination with other therapies to adults with newly diagnosed multiple brain metastases.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase to May 2017 and the National Cancer Institute Physicians Data Query for ongoing trials.

SELECTION CRITERIA

We included phase III randomised controlled trials (RCTs) comparing WBRT versus other treatments for adults with newly diagnosed multiple brain metastases.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and abstracted information in accordance with Cochrane methods.

MAIN RESULTS

We added 10 RCTs to this updated review. The review now includes 54 published trials (45 fully published reports, four abstracts, and five subsets of data from previously published RCTs) involving 11,898 participants.Lower biological WBRT doses versus controlThe hazard ratio (HR) for overall survival (OS) with lower biological WBRT doses as compared with control (3000 cGy in 10 daily fractions) was 1.21 (95% confidence interval (CI) 1.04 to 1.40; P = 0.01; moderate-certainty evidence) in favour of control. The HR for neurological function improvement (NFI) was 1.74 (95% CI 1.06 to 2.84; P = 0.03; moderate-certainty evidence) in favour of control fractionation.Higher biological WBRT doses versus controlThe HR for OS with higher biological WBRT doses as compared with control (3000 cGy in 10 daily fractions) was 0.97 (95% CI 0.83 to 1.12; P = 0.65; moderate-certainty evidence). The HR for NFI was 1.14 (95% CI 0.92 to 1.42; P = 0.23; moderate-certainty evidence).WBRT and radiosensitisersThe addition of radiosensitisers to WBRT did not confer additional benefit for OS (HR 1.05, 95% CI 0.99 to 1.12; P = 0.12; moderate-certainty evidence) or for brain tumour response rates (odds ratio (OR) 0.84, 95% CI 0.63 to 1.11; P = 0.22; high-certainty evidence).Radiosurgery and WBRT versus WBRT aloneThe HR for OS with use of WBRT and radiosurgery boost as compared with WBRT alone for selected participants was 0.61 (95% CI 0.27 to 1.39; P = 0.24; moderate-certainty evidence). For overall brain control at one year, the HR was 0.39 (95% CI 0.25 to 0.60; P < 0.0001; high-certainty evidence) favouring the WBRT and radiosurgery boost group.Radiosurgery alone versus radiosurgery and WBRTThe HR for local brain control was 2.73 (95% CI 1.87 to 3.99; P < 0.00001; high-certainty evidence)favouring the addition of WBRT to radiosurgery. The HR for distant brain control was 2.34 (95% CI 1.73 to 3.18; P < 0.00001; high-certainty evidence) favouring WBRT and radiosurgery. The HR for OS was 1.00 (95% CI 0.80 to 1.25; P = 0.99; moderate-certainty evidence). Two trials reported worse neurocognitive outcomes and one trial reported worse quality of life outcomes when WBRT was added to radiosurgery.We could not pool data from trials related to chemotherapy, optimal supportive care (OSC), molecular targeted agents, neurocognitive protective agents, and hippocampal sparing WBRT. However, one trial reported no differences in quality-adjusted life-years for selected participants with brain metastases from non-small-cell lung cancer randomised to OSC and WBRT versus OSC alone.

AUTHORS' CONCLUSIONS

None of the trials with altered higher biological WBRT dose-fractionation schemes reported benefit for OS, NFI, or symptom control compared with standard care. However, OS and NFI were worse for lower biological WBRT dose-fractionation schemes than for standard dose schedules.The addition of WBRT to radiosurgery improved local and distant brain control in selected people with brain metastases, but data show worse neurocognitive outcomes and no differences in OS.Selected people with multiple brain metastases from non-small-cell lung cancer may show no difference in OS when OSC is given and WBRT is omitted.Use of radiosensitisers, chemotherapy, or molecular targeted agents in conjunction with WBRT remains experimental.Further trials are needed to evaluate the use of neurocognitive protective agents and hippocampal sparing with WBRT. As well, future trials should examine homogeneous participants with brain metastases with focus on prognostic features and molecular markers.

Enhanced radiosensitizing by sodium glycididazole in a recurrent esophageal carcinoma tumor model

Re-irradiation is challenging for esophageal cancer patients with local-regional recurrence after initial radiotherapy. The purpose of this study is to establish a recurrent esophageal tumor model and investigate radiosensitizing effects of sodium glycididazole (CMNa). Tumor models were established by pre-irradiation (0 Gy, 10 Gy or 20 Gy) to the right hind leg of the nude mice 24 hours before tumor transplantation (ECA109 human esophageal carcinoma cells). Tumor growth curves were analyzed. Hypoxic microenvironment was exhibited in tumor frozen slides stained for pimonidazole, Hoechst 33342, hematoxylin-eosin and CD34. Mice bearing primary (0 Gy pre-irradiation) and recurrent (10 Gy pre-irradiation) tumors were randomized into control (no treatment), radiation (30 Gy in 3 weekly fractionations), or radiation combined with CMNa (1 mmol/kg i.p. injected 60 min before radiation) respectively. The data showed tumors from 10 Gy and 20 Gy pre-irradiated sites grew significantly slower than those in the 0 Gy pre-irradiated group. The recurrent xenograft tumors showed increased necrotic fractions, decreased micro-vascular density, increased pimonidazole-positive fraction, and decreased Hoechst-positive fraction. In the primary xenograft tumors, CMNa adding to radiation did not lead to significant tumor growth delay than radiation alone. However, for the recurrent tumor model, the growth rate was remarkably reduced as CMNa combined with radiation as comparison with radiation alone. In conclusion, the recurrent esophageal xenograft model with tumor bed effect was successfully established characterized by slow growth, increased hypoxia fraction and decreased blood flow. Significant radiosensitization by CMNa was demonstrated in the recurrent model.

Analysis of radio-sensitization patents in China from 2006 to 2015

INTRODUCTION

Radiotherapy is by means of ionizing radiation to kill tumor cells, inhibit and control the growth, metastasis and diffusion of tumor cells. During the last few decades, application of radiotherapy combined with chemotherapy and surgery are clinical mainstream treatments. However, little is known what radio-sensitization agents have been patented in China and what the potential drug candidates for patents are in China. Areas covered: This reviews covers research and patent literature of the last 10 years dealing with the discovery and development of novel radio-sensitization patents in China. Expert opinion: The 94 radio-sensitization patents granted from 2006 to 2015 mainly focus on six types of products. They are: traditional Chinese medicines (TCM), synthetic compounds, combinations of synthetic compounds and TCM, biological products, medical apparatus and others. In the course of tumor treatment, radiotherapy occupies an irreplaceable position. Previously believed that due to the prevalence of hypoxic cells in solid tumors, most of the tumor exist a certain degree of radiation resistance. To find effective ways to improve the sensitivity of tumor cells to radiation therapy has become a focus in scientific research and clinical treatment. So radiation sensitivity has been proposed and widely studied.

Facile Preparation and Radiotherapy Application of an Amphiphilic Block Copolymer Radiosensitizer

Radiosensitizer plays an important role in the cancer radiotherapy for efficient killing of hypoxic cancer cells at a low radiation dose. However, the commercially available small molecular radiosensitizers show low efficiency due to poor bioavailability in tumor tissues. In this report, we develop a novel amphiphilic block copolymer radiosensitizer, metronidazole-conjugated poly(ethylene glycol)-b-poly(γ-propargyl-l-glutamate) (PEG-b-P(PLG-g-MN)), which can be self-assembled into core-shell micelles (MN-Micelle) with an optimal size of ∼60 nm in aqueous solution. In vitro cytotoxicity evaluation indicated that MN-Micelle sensitized the hypoxic cancer cells more efficiently under radiation with the sensitization enhancement ratio (SER) of 1.62 as compared with that of commercially available sodium glycididazole (GS; SER = 1.17) at the metronidazole-equivalent concentration of 180 μg/mL. Upon intravenous injection of MN-Micelle into the tumor-bearing mice, high tumor deposition was achieved, which finally suppressed tumor growth completely after electron beam radiation at a low radiation dose of 4 Gy. MN-Micelle with outstanding performance as an in vivo radiosensitizer holds great potentials for translation into radiotherapy application.