Impacts of a Silver‐Coated Future

Silver is a compound that is well known for its adverse environmental effects. More recently, silver in the form of silver nanoparticles (Ag NPs) has begun to be produced in increasingly larger amounts for antibacterial purposes in, for instance, textiles, wound dressings, and cosmetics. Several authors have highlighted the potential environmental impact of these NPs. To contribute to a risk assessment of Ag NPs, we apply a suggested method named “particle flow analysis” to estimating current emissions from society to the environment. In addition, we set up explorative scenarios to account for potential technology diffusion of selected Ag NP applications. The results are uncertain and need to be refined, but they indicate that emissions from all applications included may increase significantly in the future. Ag NPs in textiles and electronic circuitry may increase more than in wound dressings due to the limited consumption of wound dressings. Due to the dissipative nature of Ag NPs in textiles, the results indicate that they may cause the highest emissions in the future, thus partly confirming the woes of both scientists and environmental organizations. Gaps in current knowledge are identified. In particular, the fate of Ag NPs during different waste‐handling processes is outlined as an area that requires more research.     

Characterization of titanium dioxide nanoparticles imprinted for tyrosine by flow field-flow fractionation and spectrofluorimetric analysis

Films based on TiO₂ nanoparticles (NPs) have been successfully used as sensing elements in chemical sensors. TiO₂ colloidal suspensions can be obtained by spontaneous hydrolysis in acidic solutions of Ti(IV) compounds. The obtained TiO₂ NPs can be employed to build up nanostructured films. With the purpose of preparing TiO₂-based nanostructured, imprinted materials as sensing elements for piezoelectric sensors, we obtained TiO₂ NP dispersions by hydrolyzing potassium titanyl oxalate in the presence of a target analyte (tyrosine). Since morphological properties of the synthesized NPs are known to influence the nanostructured film characteristics, an analytical strategy to characterize such colloidal systems can combine a size-based separation method with spectroscopic analysis to correlate the particle size distribution (PSD) with the particle-target interaction properties able to determine the sensing efficiency.In this work, we present the characterization of colloidal tyrosine-TiO₂ NP systems by flow field-flow fractionation (FlFFF) with online, UV/Vis absorption detection and offline fluorescence analysis. FlFFF eliminates the possible contribution of free tyrosine to the absorption and fluorescence properties of the NPs. FlFFF also fractionates NPs on a size basis. Particle size distribution (PSD) profiles of the fractionated NPs are then obtained by conversion of the multi-wavelength UV/Vis fractograms. Size of the fractionated NPs is finally related to fluorescence properties of the collected NPs fractions. Good correlation between the fluorescence intensity, which is proportional to the tyrosine uptake, and the FlFFF-based, NP mass-size frequency distribution finally confirms the existence of tyrosine-TiO₂ NP interaction.     

二氧化钛纳米颗粒对沼泽土壤反硝化和N2O排放的影响

近年来,二氧化钛纳米颗粒（TiO₂NPs）环境释放量不断增加,并通过多种途径进入湿地生态系统,不可避免地影响到湿地生态系统环境和功能。然而,关于TiO₂NPs对沼泽土壤反硝化作用和氧化亚氮（N₂O）排放的影响机及制尚不明确。选择典型沼泽土壤,通过室内培养实验研究土壤理化性质、反硝化酶活性、反硝化速率（DNR）和N₂O排放对不同剂量TiO₂NPs 0 mg/kg （CK）、10 mg/kg （A10）、100 mg/kg （A100）、1000 mg/kg （A1000）输入的响应,探讨TiO₂NPs输入对沼泽土壤反硝化作用和N₂O排放影响的内在机制。结果表明：不同剂量TiO₂NPs处理显著降低了土壤pH （P<0.05）,A10处理显著降低土壤总有机碳（TOC）含量（P<0.01）,A1000处理显著降低硝态氮（NO₃^--N）和亚硝态氮（NO₂^--N）含量（P<0.05）。TiO₂NPs处理抑制硝酸盐还原酶（NAR）活性,促进一氧化氮还原酶（NOR）和氧化亚氮还原酶（NOS）活性（P<0.01）,A1000处理先促进后抑制了亚硝酸盐还原酶（NIR）活性（P<0.05）。不同剂量TiO₂NPs处理抑制了土壤DNR,促进了N₂O排放,TiO₂NPs处理通过抑制NIR活性,降低土壤DNR,同时通过促进NOR活性,提高N₂O排放。综上,TiO₂NPs输入通过影响反硝化还原酶活性改变沼泽土壤反硝化过程,导致沼泽土壤N₂O排放增加,改变湿地氮的源、汇功能,影响全球气候变化。为TiO₂NPs输入的湿地环境风险评估研究提供理论基础。     

Toxicity of TiO2 Nanoparticles to Escherichia coli: Effects of Particle Size,Crystal Phase and Water Chemistry

Controversial and inconsistent results on the eco-toxicity of TiO₂ nanoparticles (NPs) are commonly found in recorded studies and more experimental works are therefore warranted to elucidate the nanotoxicity and its underlying precise mechanisms. Toxicities of five types of TiO₂ NPs with different particle sizes (10∼50 nm) and crystal phases were investigated using Escherichia coli as a test organism. The effect of water chemistry on the nanotoxicity was also examined. The antibacterial effects of TiO₂ NPs as revealed by dose-effect experiments decreased with increasing particle size and rutile content of the TiO₂ NPs. More bacteria could survive at higher solution pH (5.0–10.0) and ionic strength (50–200 mg L⁻¹ NaCl) as affected by the anatase TiO₂ NPs. The TiO₂ NPs with anatase crystal structure and smaller particle size produced higher content of intracellular reactive oxygen species and malondialdehyde, in line with their greater antibacterial effect. Transmission electron microscopic observations showed the concentration buildup of the anatase TiO₂ NPs especially those with smaller particle sizes on the cell surfaces, leading to membrane damage and internalization. These research results will shed new light on the understanding of ecological effects of TiO₂ NPs.     

Effect of TiO2 nanoparticles on some photophysical characteristics of ketocyanine dyes

The effect of titanium dioxide (TiO₂) nanoparticles (NPs) on photophysical characteristics of 2,5‐di[(E)‐1‐(4‐dimethylaminophenyl) methylidine]‐1‐cyclopentanone (2,5‐DMAPMC) and 2,5‐di[(E)‐1‐(4‐diethylaminophenyl)methylidine]‐1‐cyclopentanone (2,5‐DEAPMC) ketocyanine dyes has been studied using absorption, steady‐state and time‐resolved fluorescence spectroscopy. The magnitudes of association constants determined based on modified absorption spectrum of dyes due to the presence of TiO₂ NPs indicate the interaction of TiO₂ NPs with dye molecules. The quenching of fluorescence intensity of dyes by TiO₂ NPs is observed and it follows linear Stern‐Volmer (S‐V) equation. The magnitude of quenching rate parameter suggests the involvement of static quenching mechanism. The involvement of electron transfer process in reducing fluorescence intensity of dyes has been discussed. Also, varying influence of TiO₂ NPs on two dyes is explained based on the presence of different alkyl substituent in two dyes.     

CO2 emissions from the Chinese cement sector: Analysis from both the supply and demand sides

China is the largest producer and consumer of cement worldwide, and cement production entails the release of substantial carbon dioxide (CO₂) emissions. As the cement sector is a crucial sector of the Chinese economy, understanding the role of supply‐ and demand‐side factors may help accelerate efforts to mitigate CO₂ emissions. However, few studies have analyzed the critical factors affecting CO₂ emissions in the sector based on a combined supply‐ and demand‐side perspective. In this study, we developed an integrated framework that included eleven indicators covering both the supply and demand sides. Results revealed that improving cement production technology cannot offset CO₂ emissions from the growth in demand for cement. Improving technology on the supply side would considerably reduce CO₂ emissions from Chinese cement production; nevertheless, the combination of rapid urbanization, GDP growth, and an ultra‐high fixed capital formation ratio on the demand side increased CO₂ emissions nearly 25‐fold from 1990 to 2015. Notably, some demand‐side factors also had an effect that reduced CO₂ emissions. The in‐use stock per unit of fixed capital formation and output per in‐use stock reduced CO₂ emissions by 332 million metric tons, which is comparable to the contribution of technological progress. Based on these results, we examine why these demand‐side factors substantially influence CO₂ emissions in the Chinese cement sector, and we provide recommendations for policy‐makers on carbon‐reduction measures in this CO₂‐intensive sector.     

Titanium nanoparticles influence the Akt/Tor signal pathway in the silkworm,Bombyx mori,silk gland

Various nanoparticles, such as silver nanoparticles (AgNPs) and titanium nanoparticles (TiO₂NPs) are increasingly used in industrial processes. Because they are released into the environment, research into their influence on the biosphere is necessary. Among its other effects, dietary TiO₂NPs promotes silk protein synthesis in silkworms, which prompted our hypothesis that TiO₂NPs influence protein kinase B (Akt)/Target of rapamycin (Tor) signaling pathway (Akt/Tor) signaling in their silk glands. The Akt/Tor signaling pathway is a principle connector integrating cellular reactions to growth factors, metabolites, nutrients, protein synthesis, and stress. We tested our hypothesis by determining the influence of dietary TiO₂NPs (for 72 h) and, separately, of two Akt/Tor pathway inhibitors (LY294002 and rapamycin) on expression of Akt/Tor signaling pathway genes and proteins in the silk glands. TiO₂NPs treatments led to increased accumulation of mRNAs for Akt, Tor1 and Tor2 by 1.6‐, 12.1‐, and 4.8‐fold. Dietary inhibitors led to 2.6‐ to 4‐fold increases in mRNAs encoding Akt and substantial decreases in mRNAs encoding Tor1 and Tor2. Western blot analysis showed that dietary TiO₂NPs increased the phosphorylation of Akt and its downstream proteins. LY294002 treatments led to inhibition of Akt phosphorylation and its downstream proteins and rapamycin treatments similarly inhibited the phosphorylation of Tor‐linked downstream proteins. These findings support our hypothesis that TiO₂NPs influence Akt/Tor signaling in silk glands. The significance of this work is identification of specific sites of TiO₂NPs actions.     

Prophylactic administration of carnosine and melatonin abates the incidence of renal toxicity induced by an over dose of titanium dioxide nanoparticles

The alleviative effects of two antioxidants, carnosine (Car) and melatonin (Mel), against titanium dioxide nanoparticles (TiO₂‐NPs) toxicity‐induced oxidative and inflammatory renal damage were examined in rats. Administration of these antioxidants along with TiO₂‐NPs effectively reduced serum urea, uric acid, creatinine, glucose, tumor necrosis factor‐α, interleukin‐6, C‐reactive protein, immunoglobulin G, vascular endothelial growth factor, and nitric oxide, as well as a significant amelioration of the decrease in glutathione levels in renal tissue was observed, compared to those in rats treated with TiO₂‐NPs alone. The renoprotective properties of the antioxidants were confirmed by reduced intensity of renal damage as demonstrated by histological findings. In conclusion, Car and Mel play protective roles against TiO₂‐NPs‐induced renal inflammation and oxidative injury, likely due to their antioxidant and anti‐inflammatory properties.     

High‐Performance Electrocatalytic Conversion of N2 to NH3 Using Oxygen‐Vacancy‐Rich TiO2 In Situ Grown on Ti3C2Tx MXene

To achieve the energy‐effective ammonia (NH₃) production via the ambient‐condition electrochemical N₂ reduction reaction (NRR), it is vital to ingeniously design an efficient electrocatalyst assembling the features of abundant surface deficiency, good dispersibility, high conductivity, and large surface specific area (SSA) via a simple way. Inspired by the fact that the MXene contains thermodynamically metastable marginal transition metal atoms, the oxygen‐vacancy‐rich TiO₂ nanoparticles (NPs) in situ grown on the Ti₃C₂T_x nanosheets (TiO₂/Ti₃C₂T_x) are prepared via a one‐step ethanol‐thermal treatment of the Ti₃C₂T_x MXene. The oxygen vacancies act as the main active sites for the NH₃ synthesis. The highly conductive interior untreated Ti₃C₂T_x nanosheets could not only facilitate the electron transport but also avoid the self‐aggregation of the TiO₂ NPs. Meanwhile, the TiO₂ NPs generation could enhance the SSA of the Ti₃C₂T_x in return. Accordingly, the as‐prepared electrocatalyst exhibits an NH₃ yield of 32.17 µg h^?1 mg^?1_cat. at ?0.55 V versus reversible hydrogen electrode (RHE) and a remarkable Faradaic efficiency of 16.07% at ?0.45 V versus RHE in 0.1 m HCl, placing it as one of the most promising NRR electrocatalysts. Moreover, the density functional theory calculations confirm the lowest NRR energy barrier (0.40 eV) of TiO₂ (101)/Ti₃C₂T_x compared with Ti₃C₂T_x or TiO₂ (101) alone.     

Neurotoxicity mediated by oxidative stress caused by titanium dioxide nanoparticles in human neuroblastoma (SH-SY5Y) cells

BackgroundTitanium is widely used in biomedicine. Due to biotribocorrosion, titanium dioxide (TiO₂) nanoparticles (NPs) can be released from the titanium implant surface, enter the systemic circulation, and migrate to various organs and tissues including the brain. A previous study showed that 5 nm TiO₂ NPs reached the highest concentration in the brain. Even though TiO₂ NPs are believed to possess low toxicity, little is known about their neurotoxic effects. The aim of the study was to evaluate in vitro the effects of 5 nm TiO₂ NPs on a human neuroblastoma (SH-SY5Y) cell line.MethodsCell cultures were divided into non-exposed and exposed to TiO₂ NPs for 24 h. The following were evaluated: reactive oxygen species (ROS) generation, apoptosis, cellular antioxidant response, endoplasmic reticulum stress and autophagy.ResultsExposure to TiO₂ NPs induced ROS generation in a dose dependent manner, with values reaching up to 10 fold those of controls (p < 0.001). Nrf2 nuclear localization and autophagy, also increased in a dose dependent manner. Apoptosis increased by 4- to 10-fold compared to the control group, depending on the dose employed.ConclusionsOur results show that TiO₂ NPs cause ROS increase, induction of ER stress, Nrf2 cytoplasmic translocation to the nucleus and apoptosis. Thus, neuroblastoma cell response to TiO₂ NPs may be associated with an imbalance of the oxidative metabolism where endoplasmic reticulum-mediated signal pathway seems to be the main neurotoxic mechanism.     

Developing an antibacterial super-hydrophilic barrier between bacteria and membranes to mitigate the severe impacts of biofouling

Biofouling produces concentrated microbial populations with highly resistive biofilms and is considered to be a serious obstacle for a wide range of membrane technology applications. An antibacterial super-hydrophilic barrier could help to reduce biofouling by preventing direct contact between membranes and bacteria. In this study, an antibacterial super-hydrophilic barrier consisting of a layer of TiO₂ nanoparticles (NPs) was developed on polyvinylidene fluoride (PVDF)-based membrane via a facile technique. The results demonstrated that the presence of TiO₂ NPs eliminated the first step of biofouling, ie bacterial adhesion to the membrane. In addition, after bacterial deposition onto the membrane during ultrafiltration (UF), the TiO₂ NPs significantly retarded bacterial growth and reproduction (the second step of biofouling). During UF, the membrane flux decreased due to bacterial deposition, but 85% of the flux was recovered through physical cleaning using water. This study sheds light on the potential advantages of antibacterial super-hydrophilic membranes for biofouling mitigation.     

The Characteristics and Trends of Socioeconomic Metabolism in China

China has become the country with the largest resource use and has high levels of waste emissions that pose a great management challenge. To provide more details about environmental problems and to find effective solutions, this article analyzed the scale, structure, and trend of the socioeconomic metabolism in China during the period 1992–2014 based on economy‐wide material flow accounts (EW‐MFA), and predicted resource use during the period of the 13th Five‐Year Plan. The results of this study show that the scale of China's socioeconomic metabolism in China increased more than twofold, during 1992–2014. However, after 2011, with the economic slowdown, the growth rates of total material requirement (TMR), direct material input (DMI), and domestic processed output (DPO) began to decrease. China may reach an inflection point, but this point will probably not be approached before the year 2020. Material recycling (MR) has played an important role in improving resource productivity, improving it by 92.52 renminbi per tonne in 2014. Metallic minerals and fossil fuels are the main sources of hidden flow. Carbon dioxide (CO₂) emissions, construction waste, and agricultural emissions have become the major sources of DPO. Because of the 13th Five‐Year Plan, China may slow the growth rate of DMI and may save 10.26 gigatonnes of resources during 2015–2020. Resource productivity is predicted to increase by 15.91%. Imports and MR may play more important roles. These suggestions are made: (1) strengthening the recycling system; (2) stronger policies, especially in metallic mineral and fossil fuels; (3) developing management systems for CO₂ emissions, construction waste, and agricultural emissions; and (4) adjusting China's economic structure.     

Detection of cellular response to titanium dioxide nanoparticle agglomerates by sensor cells using heat shock protein promoter

Nanotechnology is becoming increasingly important for products used in our daily lives, such as the masses of titanium dioxide nanoparticle agglomerates (TiO₂ NPs) used in the pharmaceutical industry, for cosmetic products, or for pigments. Meanwhile, a serious lack of detailed information concerning the interaction between the nanomaterials and cells limits their biological and medical applications. Sensing technology is very important for understanding these interactions. We have shown that TiO₂ NPs induce heat shock protein 70B' (HSP70B') mRNA [Okuda‐Shimazaki et al., 2010. Int J Mol Sci 11:2383–2392]. In the current work, sensor cells for detection of cellular responses to NPs were prepared by transfecting an HSP70B' promoter–reporter plasmid. First, to find suitable cells for detection, five different mammalian cell lines were chosen as potential sensor cells. The results showed TiO₂ NP response in some cell lines, although different sensor cells had different TiO₂ NP response levels, as heat shock response ability is important for the detection. Then, we studied the TiO₂ NP time‐course response and dose response. The results indicated that our sensor cells can detect TiO₂ NP cellular responses. Our work should aid in understanding the interactions between bio‐nanomaterials and cells. Biotechnol. Bioeng. 2012; 109: 3112–3118. © 2012 Wiley Periodicals, Inc.     

Exposure–Response of Wheat Cultivars to TiO2 Nanoparticles in Contrasted Soils

Unprecedent usage of nanoparticles (NPs) over very large scale has raised concerns about their release into agro-environments. The effects of these emerging pollutants on staple food crops and contrasted soils are not very well documented. The main aim of present work was to investigate the exposure–response of 10 wheat cultivars to titanium dioxide (TiO₂) NPs (0–1000 mg kg^?1) in terms of early growth parameters followed by evaluation of the selected cultivar for complete growth cycle cultivated on contrasted soils in terms of various physicochemical characteristics. Among all the 10 tested wheat cultivars, only Galaxy cultivar sustained to the whole TiO₂ NPs exposure range. TiO₂ NPs exposure at 1000 mg kg^?1 adversely affected the early growth response parameters in MH, Ujala, Uqab, Shafaq and FSD wheat cultivars which clearly indicated the toxic effects induced by NPs. Pot studies were performed using Galaxy cultivar cultivated in different textured soils (loam and sandy loam). At the highest tested concentration of TiO₂ NPs, plant growth, biomass and phosphorus (P) concentration along with other tested parameters were not improved in both types of soils compared to their respective control groups. These results suggested the controlled use of NPs to avoid the NPs contamination in soil–plant ecosystems in the longer run.     

Titanium Dioxide Nanoparticles As Guardian against Environmental Carcinogen Benzo[alpha]Pyrene

Polycyclic aromatic hydrocarbons (PAH), like Benzo[alpha]Pyrene (BaP) are known to cause a number of toxic manifestations including lung cancer. As Titanium dioxide Nanoparticles (TiO₂ NPs) have recently been shown to adsorb a number of PAHs from soil and water, we investigated whether TiO₂ NPs could provide protection against the BaP induced toxicity in biological system. A549 cells when co-exposed with BaP (25 µM, 50 µM and 75 µM) along with 0.1 µg/ml,0.5 µg/ml and 1 µg/ml of TiO₂ NPs, showed significant reduction in the toxic effects of BaP, as measured by Micronucleus Assay, MTT Assay and ROS Assay. In order to explore the mechanism of protection by TiO₂ NP against BaP, we performed in silico studies. BaP and other PAHs are known to enter the cell via aromatic hydrocarbon receptor (AHR). TiO₂ NP showed a much higher docking score with AHR (12074) as compared to the docking score of BaP with AHR (4600). This indicates a preferential binding of TiO₂ NP with the AHR, in case if both the TiO₂ NP and BaP are present. Further, we have done the docking of BaP with the TiO₂ NP bound AHR-complex (score 4710), and observed that BaP showed strong adsorption on TiO₂ NP itself, and not at its original binding site (at AHR). TiO₂ NPs thereby prevent the entry of BaP in to the cell via AHR and hence protect cells against the deleterious effects induced by BaP.     

Cellular Toxicity of TiO2 Nanoparticles in Anatase and Rutile Crystal Phase

Titanium dioxide nanoparticles are massively produced and widely used in daily life, which has posed potential risk to human health. However, the molecular mechanism of TiO₂ nanoparticles (NPs) with different crystal phases is not clear. In this study, the characterization of two crystalline phases of TiO₂ NPs is evaluated by transmission electron microscopy and X-ray absorption fine structure spectrum; an interaction of these TiO₂ NPs with HaCaT cells is studied in vitro using transmission electron microscopy, chemical precipitation method, and X-ray absorption fine structure spectrometry. The coordination and surface properties indicate that only the anatase–TiO₂ NPs allow spontaneous reactive oxygen species (ROS) generation, but rutile–TiO₂ NPs do not after dispersion. The interaction between TiO₂ NPs and cellular components might also generate ROS for both anatase–TiO₂ NPs and rutile–TiO₂ NPs. The ROS generation could lead to cellular toxicity if the level of ROS production overwhelms the antioxidant defense of the cell or induces the mitochondrial apoptotic mechanisms. Furthermore, Ti had a direct combination with some protein or DNA after NPs enter the cell, which could also lead to cellular toxicity.     

Survey of cytotoxic and UV protection effects of biosynthesized cerium oxide nanoparticles

Cerium oxide nanoparticles (CeO₂ NPs) are among the important nanoparticles that are extensively utilized in cosmetics, automotive industries, ultraviolet (UV) filtration, gas sensors, and pharmaceutical products. In this study, CeO₂ NPs were synthesized using an aqueous extract of Ziziphus jujube fruit. The synthesized nanoparticles were characterized using UV‐visible spectroscopy, powder X‐ray diffraction, Fourier transform infrared spectroscopy, energy‐dispersive spectroscopy, field energy scanning electron microscopy, and Raman methods. The results indicated that the size of synthesized nanoparticles is between 18 and 25 nm, and they have a spherical shape. UV absorbance of the synthesized nanoparticles was measured through spectrophotometric method in the range of 290 to 320 nm. The cytotoxic activity of synthesized CeO₂ NPs against colon (HT‐29) cancer cell line was surveyed through 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. The results showed that synthesized nanoparticles are nontoxic on HT‐29 cells under 400 μg/mL concentrations after 24 hours of treatment time periods. The increase in treatment time cases increases cytotoxic activity of synthesized nanoparticles. Sun protection factor of CeO₂ NPs, as a criterion for amount of sunlight radiation protection, was determined by applying Mansur equation. The results demonstrated that synthesized CeO₂ NPs have excellent UV protection and sunscreen physical absorption properties.     

Samarium doped titanium dioxide nanoparticles as theranostic agents in radiation therapy

PurposeTitanium dioxide nanoparticles (TiO₂ NPs) have been investigated for their role as radiosensitisers for radiation therapy. The study aims to increase the efficiency of these NPs by synthesising them with samarium.MethodsSamarium-doped TiO₂ NPs (Ti(Sm)O₂ NPs) were synthesised using a solvothermal method. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS) were performed for characterising of the Ti(Sm)O₂ NPs. The intracellular uptake and cytotoxicity were assessed in vitro using A549 and DU145 cancer cell lines. Furthermore, the effect of dose enhancement and generation of reactive oxygen species (ROS) in response to 6 MV X-rays was evaluated. Additionally, the image contrast properties were investigated using computed tomography (CT) images.ResultsThe synthesised Ti(Sm)O₂ NPs were about 13 nm in diameter as determined by TEM. The XRD pattern of Ti(Sm)O₂ NPs was consistent with that of anatase-type TiO₂. EDS confirmed the presence of samarium in the nanoparticles. At 200 μg/ml concentration, no differences in cellular uptake and cytotoxicity were observed between TiO₂ NPs and Ti(Sm)O₂ NPs in both A549 and DU145 cells. However, the combination of Ti(Sm)O₂ NPs and X-rays elicited higher cytotoxic effect and ROS generation in the cells than that with TiO₂ NPs and X-rays. The CT numbers of Ti(Sm)O₂ NPs were systematically higher than that of TiO₂ NPs.ConclusionsThe Ti(Sm)O₂ NPs increased the dose enhancement of MV X-ray beams than that elicited by TiO₂ NPs. Samarium improved the efficiency of TiO₂ NPs as potential radiosensitising agent.