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Uranium is a nuclear fuel but also a hazardous contaminant due to its radioactivity and chemical toxicity. To prevent and mitigate its potential threat, the accurate monitoring of ultratrace uranium (orders of magnitude of pg g-1) in practical environmental samples has become an important scientific problem. To meet this challenge, we developed an efficient electrochemiluminescence (ECL) UO22+ detection device by a novel dual-enhancement mechanism. In detail, poly[(9,9-dioctylfuor-enyl-2,7-diyl)-alt-co-(1,4-benzo-{2,1,3}-thiadiazole)] polymer dots (Pdots) are modified by the UO22+ DNA aptamer, and rhodamine B (RhB) is combined with dsDNA to quench the ECL signal via a resonance energy transfer (RET) process. UO22+ can cut off the DNA aptamer to release RhB, which generates an ECL enhancement process, and then, UO22+ continuously combines with the DNA chain, inducing another ECL enhancement by the RET process from UO22+ to Pdots. This device achieves an ultralow detection limit (12 pg L-1) and a wide linear range (113 pg L-1-11.3 mg L-1), which can successfully give accurate determination results to the ultratrace uranium in biosamples (<1 pg g-1) to monitor the uranium simulation of fish. This work presents an efficient strategy for ultratrace uranium determination in the environment, highlighting its significance in public health and environmental fields.
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To overcome the reversible nature of low-Reynolds-number flow, a variety of biomimetic microrobotic propulsion schemes and devices capable of rapid transport have been developed. However, these approaches have been typically optimized for a specific function or environment and do not have the flexibility that many real organisms exhibit to thrive in complex microenvironments. Here, inspired by adaptable microbes and using a combination of experiment and simulation, we demonstrate that one-dimensional colloidal chains can fold into geometrically complex morphologies, including helices, plectonemes, lassos, and coils, and translate via multiple mechanisms that can be varied with applied magnetic field. With chains of multiblock asymmetry, the propulsion mode can be switched from bulk to surface-enabled, mimicking the swimming of microorganisms such as flagella-rotating bacteria and tail-whipping sperm and the surface-enabled motion of arching and stretching inchworms and sidewinding snakes. We also demonstrate that reconfigurability enables navigation through three-dimensional and narrow channels simulating capillary blood vessels. Our results show that flexible microdevices based on simple chains can transform both shape and motility under varying magnetic fields, a capability we expect will be particularly beneficial in complex in vivo microenvironments.
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Ingeniería Química , Coloides/química , Robótica , MagnetismoRESUMEN
Uranium high-efficiency separation from seawater still has some obstacles such as slow sorption rate, poor selectivity and biofouling. Herein, we report a strategy for ultrafast and highly selective uranium extraction from seawater by positively charged conjugated microporous polymers (CMPs). The polymers are synthesized by Sonogashira-Hagihara cross-coupling reaction of 1,3-dibromo-5,5-dimethylhydantoin and 1,3,5-triethynylbenzene, and then modified with oxime and carboxyl via click reaction. The CMPs show an ultrafast sorption (0.46 mg g-1 day-1) for uranium, and possess an outstanding selectivity with a high sorption capacity ratio of U/V (8.4) in real seawater. The study of adsorption process and mechanism indicate that the CMPs skeleton exhibits high affinity for uranium and can accelerate the sorption, and uranium(VI) is adsorbed on the materials by the interaction of oxime/carboxyl ligands and hydantoin. Moreover, the material can be simply loaded onto the filter membrane, and shows remarkable antibiofouling properties against E. coli and S. aureus and excellent uptake capacity for uranium with low concentration in real seawater. This work may provide a promising approach to design adsorbents with fast adsorption rate, high selectivity and antibacterial activity, and expand the thinking over the development of novel and highly efficient adsorbents for uranium extraction from seawater.
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Incrustaciones Biológicas , Polímeros , Uranio , Incrustaciones Biológicas/prevención & control , Escherichia coli , Agua de Mar , Staphylococcus aureusRESUMEN
Uranium(vi) is one of the main sources in nuclear energy but can cause severe effects to human health and the environment, therefore it is important to develop a new method and materials for uranium capture. A novel approach is reported here for efficient uranium sorption by polyamidoxime-functionalized colloids with zeta potential-assistance. Specifically, colloidal particles were prepared via emulsion polymerization with (3-acrylamidopropyl)trimethyl-ammonium chloride (MAPTAC). The zeta potential of the colloids could be controlled by the concentration of MAPTAC. The effects of pH, the sorbent dose and competing ions on uranium(vi) sorption were investigated. The sorption process followed a pseudo-second-order kinetics and could reach equilibrium within 3.5 h at pH 7.8. The colloidal particles with high zeta potentials showed higher selectivity, faster kinetics and larger capacity for the sorption of uranium(vi) in comparison with that of negative zeta potential particles. This work may provide a new method for efficient uranium(vi) capture from aqueous solution through zeta potential-assisted sorption.
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Carbonatos/aislamiento & purificación , Coloides/química , Oximas/química , Uranio/aislamiento & purificación , Contaminantes Radiactivos del Agua/aislamiento & purificación , Adsorción , Cinética , Termodinámica , Purificación del Agua/métodosRESUMEN
The risk of radiation exposure increases with the development of nuclear energy and technology, and radiation protection receives more and more attention from public health and safety. However, the numerous adverse effects and low drug utilization limit the practical applications of radioprotective agents. In this study, we developed a biogenic crocetin-crosslinked chitosan nanoparticle with high stability and drug loading for efficient radioprotection. In detail, the nanoparticles were prepared using the natural antioxidant crocetin as a cross-linking reagent in amidation reactions of chitosan and mPEG-COOH. The nanoparticles exhibit a quick scavenging ability for common reactive oxygen species and reactive nitrogen in vitro. Meanwhile, cellular experiments demonstrate the good biocompatibility of the nanoparticles and the alleviation of radiation damage by scavenging reactive oxygen species, reducing apoptosis, and inhibiting DNA damage, etc. Importantly, the nanoparticles are effective in mitigating oxidative damage in major organs and maintaining peripheral blood cell content. In addition, they perform better radioprotective properties than free drug due to the significant extension of the blood half-life of crocetin in vivo from 10 min to 5 h. This work proposes a drug-crosslinking strategy for the design of a highly efficient radioprotective agent, which exhibits a promising prospect in the fields of nuclear emergency and public health.
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Carotenoides , Quitosano , Nanopartículas , Protección Radiológica , Protectores contra Radiación , Vitamina A/análogos & derivados , Quitosano/farmacología , Especies Reactivas de Oxígeno , Protectores contra Radiación/farmacologíaRESUMEN
Radiation-induced lung injury (RILI) is one of the major complications in patients exposed to accidental radiation and radiotherapy for thoracic malignancies. However, there is no reliable radioprotector for effective clinical treatment of RILI so far. Herein, a novel Crocin-loaded chitosan microsphere is developed for lung targeting and attenuation of RILI. The chitosan microspheres are modified with 4-carboxyphenylboronic acid and loaded with the natural antioxidant Crocin-I to give the drug-loaded microspheres (~10 µm). The microspheres possess good biocompatibility in vivo and in vitro. In a mouse model, they exhibit effective passive targeting performance and a long retention time in the lung after intravenous administration. Furthermore, they improve the radioprotective effect of Crocin-I for the treatment of RILI by reducing the level of inflammatory cytokines in bronchoalveolar lavage fluid and by regulating oxidative stress in lung tissues. The targeted agents significantly improved the bioavailability and radioprotection of Crocin-I by the outstanding passive targeting effect. This work may provide a promising strategy for efficient radioprotection on RILI using passive lung targeting microspheres.
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Quitosano , Lesión Pulmonar , Animales , Ratones , Lesión Pulmonar/tratamiento farmacológico , Lesión Pulmonar/prevención & control , Quitosano/uso terapéutico , Especies Reactivas de Oxígeno , Microesferas , Pulmón/patologíaRESUMEN
Trace iodine (I2) radioisotopes are commonly regarded as an indicator in nuclear security early warnings. Herein, we develop a visualized I2 real-time monitoring system using electrochemiluminescence (ECL) imaging technology for the first time. In detail, the polymers based on poly [(9,9-dioctylfluorene-alkenyl-2,7-diyl)-alt-co-(1,4-benzo-{2,1',3}-thiadiazole)] are synthesized for iodine detection. An ultra-low limit of detection (0.01 ppt) to iodine can be achieved by adding the modification ratio of tertiary amine onto PFBT as a co-reactive group, which is the lowest detection limit in known iodine vapor sensors. This result can be attributed to the co-reactive group poisoning response mechanism. Considering to the strong ECL behavior of this polymer dots, P-3 Pdots with ultra-low detection limit for iodine is combined with ECL imaging technology to realize the visualized rapid I2 vapor response with high selectivity. ECL imaging component based on ITO electrode can make iodine monitoring system more convenient and suitable for real-time detection in early warning of nuclear emergency. The detection result cannot be affected by vapor of organic compounds, humidity and temperature, indicating a good selectivity to iodine. This work provides a strategy for nuclear emergency early warning, showing its significance in environmental and nuclear security fields.
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The capture of radioiodine is crucial for nuclear security and environmental protection due to its volatility and superior environmental fluidity. Herein, we propose a strategy of "temperature-dependent gate" based on a swellable conjugated microporous polymer (SCMP) to significantly improve the capture of volatile iodine. The SCMP is constructed via the Buchwald-Hartwig coupling reaction of building monomers containing amines. It possesses a hierarchical pore structure with restricted pores, which can be "opened" and "closed" by changing the temperature. By virtue of the thermal-responsive pore structure, it reaches adsorption equilibrium for iodine in 2 h with a capacity of 4.3 g g-1 at 90 °C and retains 92.8% adsorbed iodine at room temperature. The SCMP also exhibits a high adsorption capacity up to 3.5 g g-1 for dissolved iodine within 10 min, as well as good radiation resistance and high selectivity for iodine against moisture, VOCs, and HNO3 vapor. The mechanism is clarified for effective iodine capture and caging based on the relationship between temperature and the pore structure. This work develops not only a strategy to enhance the capture of gaseous and dissolved iodine but also a new adsorption mechanism for iodine capture, which can be extended to the separation and caging of resources or volatile pollutants in other fields.
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Efficient separation and enrichment of uranium from radioactive effluents is of strategic significance for sustainable development of nuclear energy and environmental protection. Macropore structure of adsorbent is conducive to accessibility of the pore and transport of the adsorbate during dynamic adsorption. However, the low specific surface area results in fewer ligand sites and subsequently reduces the adsorption capacity. Herein, we present a novel strategy for efficient dynamic uranium enrichment using polyphosphonate-segmented macroporous organosilicon frameworks (PMOFs). PMOFs are constructed through the copolymerization of diethyl vinylphosphonate and triethoxyvinylsilane, followed by hydrolysis and condensation of the oligomers. The introduction of polyphosphonate segments into the frameworks endows PMOFs with a macroporous structure (31 µm) and a high ligand content (up to 72 wt%). Consequently, the optimized PMOF-3 demonstrated an ultrahigh dynamic adsorption capacity of 114.8 mg/g among covalently conjugated silicon-based materials. Additionally, PMOF-3 achieves a high enrichment factor (120) in the dynamic enrichment of uranium on a fixed bed column, which can be in-situ regenerated with 1 M NaHCO3 as the eluent. This work presents a new strategy for efficient dynamic enrichment of nuclides, which can be extended to the separation of other specific pollutants, shedding new light on adsorbent design and technical innovation.
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Radiobiological damage can be caused by radiation, and easy preparation of long-term stable radioprotectors is helpful for timely and efficient response to radiation emergencies. This study develops an ultra-stable radioprotector for rapid nuclear emergency with a simple preparing method. First of all, polyvinylpyrrolidone-modified MnO2 nanoparticles (PVP-MnO2 NPs) are obtained by one-pot synthesis with ultra-stability (remaining for at least three years) and multiple free radical scavenging activities. In the synthesis process, PVP acts as a reducing agent, a surfactant (soft template), and a steric stabilizer. PVP-MnO2 NPs can improve the survival rates of irradiated cells by effectively scavenging free radicals and protecting DNA from radiation damage. Besides, PVP-MnO2 NPs can also prevent peripheral blood cell and organ damage induced by radiation, and improve the survival rate of irradiated mice. Finally, PVP-MnO2 NPs are mainly metabolized by liver and kidney in mice, and basically excreted 72 h after administration. These results indicate that PVP-MnO2 NPs exhibit good biosafety and radioprotection activity, which is significant for the development of radioprotection agents.
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Nanopartículas , Protección Radiológica , Ratones , Animales , Povidona , Compuestos de Manganeso/farmacología , ÓxidosRESUMEN
The World Health Organization has reported radioactive Rn gas as the second leading cause of lung cancer and gives an extreme limit to indoor Radon (Rn) concentration as 100 Bq/m3. To realize rapid and accurate Rn monitoring, we report an efficient visualized electrochemiluminescence (ECL) device for Rn detection with the lowest limit of detection (0.9 Bq/m3/3.6 Bq h m-3) compared to known Rn detection methods and the shortest measurement time (less than 5 h) among non-pump methods. In detail, an efficient Rn probe is prepared by Au nanoparticles, Pb2+ aptamer, as well as NH2-ssDNA co-reactant and then modified on ITO electrodes to obtain Rn detection devices. With tris(2,2'-bipyridyl)ruthenium(II)chloride (Ru(bpy)3Cl2) as an ECL emitter, the devices can exhibit ultra-high sensitivity and selectivity to trace Rn in environment via the ECL quenching caused by 210Pb, the relatively stable decay product of Rn. Furthermore, ECL imaging technology can be applied to realize the visualized Rn detection. An efficient up-response ECL detector was also invented to support this detection device to achieve accurate Rn detection in environment. This work reports noble gas ECL detection for the first time and provides an efficient strategy for rapid and accurate monitoring of trace Rn in environment.
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Uranium extraction is highly challenging because of low uranium concentration, high salinity, and a large number of competing ions in different environments. The template strategy is developed to address the defect of poor selectivity, but the adsorption capacity is limited by cavity blocking during the preparation of materials. Herein, a two-dimensional (2D) imprinting strategy is adopted to design 2D imprinted networks with specific nanotraps for effective uranium capture. The imprinted networks are established through the condensation polymerization of uranyl complexes, which are formed by aromatic building units coordinating with uranyl ions on the equatorial plane. Different from traditional imprinting materials that contain many invalid cavities (buried cavities or unreleased cavities), the as-prepared adsorbents possess tailored 2D nanotraps, which are open and specific to uranyl. Thus, the optimized networks not only show excellent selectivity for uranium (Kd = 964,500 mL/g in multi-ion solution) and slight disturbance of high salinity but also possess an ultrahigh adsorption capacity of 1365.7 mg/g. In addition, this adsorbent shows a high extraction efficiency for uranium under a wide range of pH conditions and exhibits good regeneration performance. This work proposes a pioneering strategy of 2D imprinting networks to capture uranium specifically with high capacity and can be applied to material design in many other fields.
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The recovery of radioactive ions from high salinity low-level radioactive wastewater (LLRW) is important for the sustainable utilization of nuclear energy. Previous work primarily focuses on developing adsorbents that remove individual types of ions via physicochemical adsorption. Here, we report a new strategy for the simultaneous recovery of uranium (UO22+) and rhenium (ReO4-) as a non-radioactive surrogate of technetium from LLRW via electro-adsorption. Carboxyl functionalized covalent organic frameworks (COF-1) and cationic covalent organic frameworks (COF-2) were prepared as cathode and anode materials, respectively. The adsorption capacities were 411 mg U/g for COF-1 and 984 mg Re/g for COF-2 under 1.2 direct-current (DC) volts, 2.5 and 2.1 times higher than the capacities of the same adsorbents obtained by physicochemical adsorption. We also found that the electro-adsorption of uranium and rhenium follows pseudo-second-order kinetics with the adsorption rates of 0.45 and 1.05 g/mg/h at pH 7.0 and 298.15 K, again two times faster than those measured in physicochemical adsorption. Therefore, electro-adsorption improves both adsorption capacity and kinetics by maximizing the utility of available active sites in adsorbents and facilitating ion migration towards the adsorbents. The adsorption efficiencies for uranium and rhenium reached 65.9% and 89.2%, respectively, after electro-adsorption for 2 h. The high efficiencies can be maintained after five adsorption-desorption cycles. Furthermore, the electrodes showed high selectivity for uranium(VI) and rhenium(VII) and excellent salt resistance even in 1 mol/L NaCl solution. XPS studies revealed that covalent bonds were formed between uranium(VI) and carboxyl groups on COF-1, and rhenium(VII) was bound to cationic COF-2 through electrostatic interaction. Our asymmetric electrodes design can be extended to simultaneously and efficiently remove other types of radioactive or heavy metal ions from wastewater.
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Estructuras Metalorgánicas , Uranio , Adsorción , Electrodos , Cinética , Uranio/químicaRESUMEN
A booming demand for energy highlights the importance of an emergency cleanup system in the nuclear industry or hydrogen-energy sector to reduce the risk of hydrogen explosion and decrease tritium emission. The properties of the catalyst determine the efficiency of hydrogen isotope enrichment and removal in the emergency cleanup system. However, the aggregation behavior of Pt, deactivation effect of water vapor, and isotope effect induce a continuous decrease in the catalytic activity of the Pt catalyst. Herein, a de novo design of a Pt nanocatalyst is proposed for catalytic oxidation of the hydrogen isotope via modification of a conjugated microporous polymer onto honeycomb cordierite as a Pt support. The conjugated microporous polymer creates a microporous and hydrophobic environment to attenuate the deactivation effect of water vapor and shape Pt nanoparticles with a diameter of around 2.4 nm. Thus, the as-prepared catalysts exhibit excellent catalytic performance in the range of 25-65 °C and high space velocity (≤30â¯000 h-1) and a stable and high catalytic activity during 487 h of continuous and intermittent operation. Importantly, the charge of the Pt nanoparticles is redistributed by the conjugated skeletons, leading to a decreased energy barrier in the rate-limiting step of hydrogen isotope oxidation and a reduced isotope effect.
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With the progress of nuclear technology including radiotherapy and radiodiagnosis, radiation has been widely used in many fields as a powerful diagnostic and therapeutic tool in the medical area. Unfortunately, acute radiation disease will occur if the human body is accidentally exposed to a large dosage of ionizing radiation. However, clinical radioprotective agents are being challenged by the short half-life and several side effects. In this work, a reactive oxygen species-responsive nanodrug is developed for efficient radioprotection. The nanodrug was prepared by modifying Crocin-I with 4-pentylphenylboronic acid (PBA) and exhibited effective responsiveness and scavenging activity of reactive oxygen species. PBA-Crocin nanodrug displayed good biocompatibility and radioprotection effect compared to Crocin-I in vitro. The survival rate of cells treated with PBA-Crocin (10 µg mL-1) is comparable to that treated with amifostine (12.5 µg mL-1, the only radioprotector approved by the United States Food and Drug Administration clinically) after 6 Gy irradiation. Importantly, PBA-Crocin resulted in markedly prevention of radiation-induced damage in peripheral blood cells and a 1.6-fold longer retention time of Crocin-I in plasma in comparison with Crocin-I. The finding suggests a new design for natural medicine in effective radioprotection.
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Amifostina , Nanopartículas , Protectores contra Radiación , Carotenoides , Humanos , Nanopartículas/uso terapéutico , Protectores contra Radiación/farmacología , Especies Reactivas de Oxígeno , Estados UnidosRESUMEN
Manipulating recognition and transport at the nanoscale holds great promise for technological breakthroughs in energy conversion, catalysis, and information processing. Living systems evolve specialized membrane proteins (MPs) embedded in lipid bilayers to exquisitely control communications across the insulating membrane boundaries. Harnessing MP functions directly in synthetic systems opens up enormous opportunities for nanotechnology, but there exist fundamental challenges of how to address the labile nature of lipid bilayers that renders them of inadequate value under a broad range of harsh non-biological conditions, and how to reconstitute MPs coherently in two or three dimensions into non-lipid-based artificial membranes. Here we show that amphiphilic block copolymers can be designed to direct proteorhodopsin reconstitution and formation of hierarchically ordered proteopolymer membrane arrays spontaneously, even when the membrane-forming polymer blocks are in entangled states. These findings unfold a viable approach for the development of robust and chemically versatile nanomembranes with MP-regulated recognition and transport performance.
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Membranas Artificiales , Polímeros/química , Análisis por Matrices de Proteínas , Rodopsina/química , Nanotecnología , Tamaño de la Partícula , Rodopsinas Microbianas , Propiedades de SuperficieRESUMEN
Separation of uranium and cesium from low-level radioactive effluents (LLRE) is of great significance for sustainable development of the nuclear industry and for the environment. However, high salinity and massive coexisting ions of LLRE are giant challenges for the separation. To address the challenges, we report a strategy for efficient and simultaneous separation of uranium and cesium from a high-salt environment by dual ion-imprinted mesoporous silica based on multiple interactions. The as-prepared adsorbents can reach equilibrium for uranium and cesium within 1 h with a maximum capacity of 221.7 mg U g-1 and 34.5 mg Cs g-1. The sorption mechanism demonstrates that the highly active phenolic hydroxyl groups of imprinted cavities can extract uranium and cesium effectively through multiple interactions, including coulomb attraction, redox, ion exchange, and complexation. The synergism of multiple interactions and imprinted cavity endows the sorbent with good selectivity for uranium and cesium over other cations and with excellent salt tolerance. This work demonstrates a new strategy of selective extraction of nuclides by multifunction adsorbent through multiple interactions.
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To deal with regeneration of nuclear-waste-contaminated soil, it is important to develop new materials and techniques for effective removal of radioactive cesium ions from clay. We report herein a synergistic remediation method for cleaning cesium-contaminated clay by Prussian blue analogue-functionalized magnetic microgel along with ionized chitosan. The magnetic microgels were prepared by surface polymerization of 4-vinyl pyridine and styrene on magnetite nanoparticles and attachment of Prussian blue analogues by ligand exchange reaction. The adsorption of cesium ions by magnetic microgels in aqueous solution follows the second-order kinetics process. And the maximum adsorption capacity was determined to be 149.70 mg/g by Langmuir adsorption model. When ionized chitosan hydrochloride was mixed with cesium-contaminated clay, we found that 200 mg/g clay of chitosan hydrochloride can realize 87.6 % of cesium release from clay within 2 h. Further use of magnetic microgel adsorbents can adsorb 95.5 % free cesium ions in solution, achieving an overall 83.7 % cleaning efficiency from cesium-contaminated clays. The microgels can be regenerated effectively and recycled magnetically while keeping the adsorption capacity constant after multiple times of use. The underlying principle demonstrated in this work can be extended to remediation of other types of radionuclides or heavy-metal ions in contaminated soil.
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High-dose ionizing radiation can lead to death from the unrecoverable damage of the gastrointestinal tract, especially the small intestine. Until now, the lack of predilection for the small intestine and rapid clearance by digestive fluids limit the effects of conventional radioprotective formulations. Herein, an innovative radioprotective strategy is developed for attenuating gastrointestinal syndrome by smart oral administration nanodrugs. The nanodrug is first engineered by encapsulating thalidomide into chitosan-based nanoparticles, and then coated with polydopamine. The behaviors of gastric acid-resistance, and pH-switchable controlled release in the small intestine enhance the oral bioavailability of the pyroptosis inhibitor thalidomide. In a mouse model, nanodrugs demonstrate prolonged small intestinal residence time and accessibility to the crypt region deep in the mucus. Furthermore, the nanodrugs ameliorate survival rates of C57BL/6J mice irradiated by 14 Gy of subtotal body irradiation and also maintain their epithelial integrity. This work may provide a promising new approach for efficiently attenuating lethal radiation-induced gastrointestinal syndrome and add insights into developing nanodrug-based therapies with improved efficacy and minimum side effects.
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Protectores contra Radiación , Administración Oral , Animales , Indoles , Ratones , Ratones Endogámicos C57BL , PolímerosRESUMEN
Because of the rapid development and extensive use of nuclear technology, ionizing radiation has become a large threat to human health. Until now, there has been no practicable radioprotector for routine clinical application because of severe side effects, high toxicity, and short elimination half-life. Herein, we develop a highly efficient radioprotection strategy using a selenium-containing polymeric drug with low toxicity and long circulation by removing reactive oxygen species (ROSs). The selenium-containing polymeric drug is prepared by copolymerization of vinyl phenylselenides (VSe) and N-(2-hydroxyethyl) acrylamide (HEA). The in vitro radioprotective efficacy of the polymeric drug is increased by 40% with lower cytotoxicity compared with the small-molecular VSe monomer. Importantly, the radioprotection activity of the polymeric drug shows more remarkable effects both in cell culture and mice model compared to the commercially available drug ebselen and also exhibits a much longer retention time in blood (half-life â¼ 10 h). This work may unfold a new area for highly efficient radioprotection by polymeric drugs instead of small-molecular agents.