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“Effect of operating and sampling conditions on the exhaust gas composition of small-scale power generators”. Smits M, Vanpachtenbeke F, Horemans B, De Wael K, Hauchecorne B, Van Langenhove H, Demeestere K, Lenaerts S, PLoS ONE 7, e32825 (2012). http://doi.org/10.1371/JOURNAL.PONE.0032825
Abstract: Small stationary diesel engines, like in generator sets, have limited emission control measures and are therefore responsible for 44% of the particulate matter (PM) emissions in the United States. The diesel exhaust composition depends on operating conditions of the combustion engine. Furthermore, the measurements are influenced by the used sampling method. This study examines the effect of engine loading and exhaust gas dilution on the composition of small-scale power generators. These generators are used in different operating conditions than road-transport vehicles, resulting in different emission characteristics. Experimental data were obtained for gaseous volatile organic compounds (VOC) and PM mass concentration, elemental composition and nitrate content. The exhaust composition depends on load condition because of its effect on fuel consumption, engine wear and combustion temperature. Higher load conditions result in lower PM concentration and sharper edged particles with larger aerodynamic diameters. A positive correlation with load condition was found for K, Ca, Sr, Mn, Cu, Zn and Pb adsorbed on PM, elements that originate from lubricating oil or engine corrosion. The nitrate concentration decreases at higher load conditions, due to enhanced nitrate dissociation to gaseous NO at higher engine temperatures. Dilution on the other hand decreases PM and nitrate concentration and increases gaseous VOC and adsorbed metal content. In conclusion, these data show that operating and sampling conditions have a major effect on the exhaust gas composition of small-scale diesel generators. Therefore, care must be taken when designing new experiments or comparing literature results.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.806
Times cited: 5
DOI: 10.1371/JOURNAL.PONE.0032825
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“Cold atmospheric plasma treatment of melanoma and glioblastoma cancer cells”. Vermeylen S, De Waele J, Vanuytsel S, De Backer J, Van der Paal J, Ramakers M, Leyssens K, Marcq E, Van Audenaerde J, L J Smits E, Dewilde S, Bogaerts A, Plasma processes and polymers 13, 1195 (2016). http://doi.org/10.1002/ppap.201600116
Abstract: In this paper, two types of melanoma and glioblastoma cancer cell lines are treated with cold atmospheric plasma to assess the effect of several parameters on the cell viability. The cell viability decreases with treatment duration and time until analysis in all cell lines with varying sensitivity. The majority of dead cells stains both AnnexinV (AnnV) and propidium iodide, indicating that the plasma-treated non-viable cells are mostly late apoptotic or necrotic. Genetic mutations might be involved in the response to plasma. Comparing the effects of two gas mixtures, as well as indirect plasma-activated medium versus direct treatment, gives different results per cell line. In conclusion, this study confirms the potential of plasma for cancer therapy and emphasizes the influence of experimental parameters on therapeutic outcome.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.846
Times cited: 26
DOI: 10.1002/ppap.201600116
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“Concept and validation of a fully automated photocatalytic test setup”. Tytgat T, Hauchecorne B, Smits M, Verbruggen S, Lenaerts S, Journal of laboratory automation 17, 134 (2012). http://doi.org/10.1177/2211068211424554
Abstract: Photocatalytic activity can be studied by several methods, each with its own strengths and weaknesses. To study photocatalytic activity in an easy, user-friendly, and realistic way, a completely new setup has been built. The setup is modularly constructed around Fourier transform infrared spectroscopy (FTIR) spectroscopy at the heart of it, resulting in great versatility. Complementary software has been written for automatic control of the setup and for processing the generated data. Two pollutants, oil and n-octane, are tested to validate the performance of the setup. These validation experiments confirm the usefulness and added value of the setup in general and of the FTIR detection methodology as well. It becomes clear that a system of online measurements with good repeatability, accuracy, and user-friendliness has been created.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.85
Times cited: 15
DOI: 10.1177/2211068211424554
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“Photocatalytic removal of soot : unravelling of the reaction mechanism by EPR and in situ FTIR spectroscopy”. Smits M, Ling Y, Lenaerts S, Van Doorslaer S, ChemPhysChem : a European journal of chemical physics and physical chemistry 13, 4251 (2012). http://doi.org/10.1002/CPHC.201200674
Abstract: Photocatalytic soot oxidation is studied on P25 TiO2 as an important model reaction for self-cleaning processes by means of electron paramagnetic resonance (EPR) and Fourier transform infrared (FTIR) spectroscopy. Contacting of carbon black with P25 leads on the one hand to a reduction of the local dioxygen concentration in the powder. On the other hand, the weakly adsorbed radicals on the carbon particles are likely to act as alternative traps for the photogenerated conduction-band electrons. We find furthermore that the presence of dioxygen and oxygen-related radicals is vital for the photocatalytic soot degradation. The complete oxidation of soot to CO2 is evidenced by in situ FTIR spectroscopy, no intermediate CO is detected during the photocatalytic process.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 3.075
Times cited: 9
DOI: 10.1002/CPHC.201200674
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“Liquid treatment with a plasma jet surrounded by a gas shield: effect of the treated substrate and gas shield geometry on the plasma effluent conditions”. Heirman P, Verloy R, Baroen J, Privat-Maldonado A, Smits E, Bogaerts A, Journal of physics: D: applied physics 57, 115204 (2024). http://doi.org/10.1088/1361-6463/ad146b
Abstract: The treatment of a well plate by an atmospheric pressure plasma jet is common for<italic>in vitro</italic>plasma medicine research. Here, reactive species are largely produced through the mixing of the jet effluent with the surrounding atmosphere. This mixing can be influenced not only by the ambient conditions, but also by the geometry of the treated well. To limit this influence and control the atmosphere, a shielding gas is sometimes applied. However, the interplay between the gas shield and the well geometry has not been investigated. In this work, we developed a 2D-axisymmetric computational fluid dynamics model of the kINPen plasma jet, to study the mixing of the jet effluent with the surrounding atmosphere, with and without gas shield. Our computational and experimental results show that the choice of well type can have a significant influence on the effluent conditions, as well as on the effectiveness of the gas shield. Furthermore, the geometry of the shielding gas device can substantially influence the mixing as well. Our results provide a deeper understanding of how the choice of setup geometry can influence the plasma treatment, even when all other operating parameters are unchanged.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 3.4
DOI: 10.1088/1361-6463/ad146b
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“Phototoxicity and cell passage affect intracellular reactive oxygen species levels and sensitivity towards non-thermal plasma treatment in fluorescently-labeled cancer cells”. Verswyvel H, Deben C, Wouters A, Lardon F, Bogaerts A, Smits E, Lin A, Journal of physics: D: applied physics 56, 294001 (2023). http://doi.org/10.1088/1361-6463/accc3d
Abstract: Live-cell imaging with fluorescence microscopy is a powerful tool, especially in cancer research, widely-used for capturing dynamic cellular processes over time. However, light-induced toxicity (phototoxicity) can be incurred from this method, via disruption of intracellular redox balance and an overload of reactive oxygen species (ROS). This can introduce confounding effects in an experiment, especially in the context of evaluating and screening novel therapies. Here, we aimed to unravel whether phototoxicity can impact cellular homeostasis and response to non-thermal plasma (NTP), a therapeutic strategy which specifically targets the intracellular redox balance. We demonstrate that cells incorporated with a fluorescent reporter for live-cell imaging have increased sensitivity to NTP, when exposed to ambient light or fluorescence excitation, likely through altered proliferation rates and baseline intracellular ROS levels. These changes became even more pronounced the longer the cells stayed in culture. Therefore, our results have important implications for research implementing this analysis technique and are particularly important for designing experiments and evaluating redox-based therapies like NTP.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 3.4
DOI: 10.1088/1361-6463/accc3d
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“Toward defining plasma treatment dose : the role of plasma treatment energy of pulsed‐dielectric barrier discharge in dictating in vitro biological responses”. Lin A, Biscop E, Gorbanev Y, Smits E, Bogaerts A, Plasma Processes And Polymers 19, e2100151 (2022). http://doi.org/10.1002/PPAP.202100151
Abstract: The energy dependence of a pulsed-dielectric barrier discharge (DBD) plasma treatment on chemical species production and biological responses was investigated. We hypothesized that the total plasma energy delivered during treatment encompasses the influence of major application parameters. A microsecond-pulsed DBD system was used to treat three different cancer cell lines and cell viability was analyzed. The energy per pulse was measured and the total plasma treatment energy was controlled by adjusting the pulse frequency, treatment time, and application distance. Our data suggest that the delivered plasma energy plays a predominant role in stimulating a biological response in vitro. This study aids in developing steps toward defining a plasma treatment unit and treatment dose for biomedical and clinical research.
Keywords: A1 Journal article; Pharmacology. Therapy; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.5
DOI: 10.1002/PPAP.202100151
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“Characterization of Non-Thermal Dielectric Barrier Discharges for Plasma Medicine: From Plastic Well Plates to Skin Surfaces”. Lin A, Gromov M, Nikiforov A, Smits E, Bogaerts A, Plasma Chemistry and Plasma Processing 43, 1587 (2023). http://doi.org/10.1007/s11090-023-10389-w
Abstract: technologies have been expanding, and one of the most exciting and rapidly growing
applications is in biology and medicine. Most biomedical studies with DBD plasma systems are performed in vitro, which include cells grown on the surface of plastic well plates, or in vivo, which include animal research models (e.g. mice, pigs). Since many DBD systems use the biological target as the secondary electrode for direct plasma generation and treatment, they are sensitive to the surface properties of the target, and thus can be altered based on the in vitro or in vivo system used. This could consequently affect biological response from plasma treatment. Therefore, in this study, we investigated the DBD plasma behavior both in vitro (i.e. 96-well flat bottom plates, 96-well U-bottom plates, and 24-well flat bottom plates), and in vivo (i.e. mouse skin). Intensified charge coupled device (ICCD) imaging was performed and the plasma discharges were visually distinguishable between the different systems. The geometry of the wells did not affect DBD plasma generation for low application distances (≤ 2 mm), but differentially affected plasma uniformity on the bottom of the well at greater distances. Since DBD plasma treatment in vitro is rarely performed in dry wells for plasma medicine experiments, the effect of well wetness was also investigated. In all in vitro cases, the uniformity of the DBD plasma was affected when comparing wet versus dry wells, with the plasma in the wide-bottom wells appearing the most similar to plasma generated on mouse skin. Interestingly, based on quantification of ICCD images, the DBD plasma intensity per surface area demonstrated an exponential one-phase decay with increasing application distance, regardless of the in vitro or in vivo system. This trend is similar to that of the energy per pulse of plasma, which is used to determine the total plasma treatment energy for biological systems. Optical emission spectroscopy performed on the plasma revealed similar trends in radical species generation between the plastic well plates and mouse skin. Therefore, taken together, DBD plasma intensity per surface area may be a valuable parameter to be used as a simple method for in situ monitoring during biological treatment and active plasma treatment control, which can be applied for in vitro and in vivo systems.
Keywords: A1 Journal Article; Non-thermal plasma · Plasma medicine · Dielectric barrier discharge · Plasma diagnostics · Plasma surface interaction · In situ plasma monitoring; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.6
DOI: 10.1007/s11090-023-10389-w
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“Anti-cancer capacity of plasma-treated PBS: effect of chemical composition on cancer cell cytotoxicity”. Van Boxem W, Van der Paal J, Gorbanev Y, Vanuytsel S, Smits E, Dewilde S, Bogaerts A, Scientific reports 7, 16478 (2017). http://doi.org/10.1038/s41598-017-16758-8
Abstract: We evaluate the anti-cancer capacity of plasma-treated PBS (pPBS), by measuring the concentrations of NO2 − and H2O2 in pPBS, treated with a plasma jet, for different values of gas flow rate, gap and plasma treatment time, as well as the effect of pPBS on cancer cell cytotoxicity, for three different glioblastoma cancer cell lines, at exactly the same plasma treatment conditions. Our experiments reveal that pPBS is cytotoxic for all conditions investigated. A small variation in gap between plasma jet and liquid surface (10 mm vs 15 mm) significantly affects the chemical composition of pPBS and its anti-cancer capacity, attributed to the occurrence of discharges onto the liquid. By correlating the effect of gap, gas flow rate and plasma treatment time on the chemical composition and anti-cancer capacity of pPBS, we may conclude that H2O2 is a more important species for the anti-cancer capacity of pPBS than NO2 −. We also used a 0D model, developed for plasma-liquid interactions, to elucidate the most important mechanisms for the generation of H2O2 and NO2 −. Finally, we found that pPBS might be more suitable for practical applications in a clinical setting than (commonly used) plasma-activated media (PAM), because of its higher stability.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.259
Times cited: 40
DOI: 10.1038/s41598-017-16758-8
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“Critical Evaluation of the Interaction of Reactive Oxygen and Nitrogen Species with Blood to Inform the Clinical Translation of Nonthermal Plasma Therapy”. Lin A, Biscop E, Breen C, Butler SJ, Smits E, Bogaerts A, Jakovljevic V, Oxidative Medicine And Cellular Longevity 2020, 1 (2020). http://doi.org/10.1155/2020/9750206
Abstract: Non-thermal plasma (NTP), an ionized gas generated at ambient pressure and temperature, has been an emerging technology for medical applications. Through controlled delivery of reactive oxygen and nitrogen species (ROS/RNS), NTP can elicit hormetic cellular responses, thus stimulating broad therapeutic effects. To enable clinical translation of the promising preclinical research into NTP therapy, a deeper understanding of NTP interactions with clinical substrates is profoundly needed. Since NTP-generated ROS/RNS will inevitably interact with blood in several clinical contexts, understanding their stability in this system is crucial. In this study, two medically relevant NTP delivery modalities were used to assess the stability of NTP-generated ROS/RNS in three aqueous solutions with increasing organic complexities: phosphate-buffered saline (PBS), blood plasma (BP), and processed whole blood. NTP-generated RNS collectively (NO2−, ONOO−), H2O2, and ONOO− exclusively were analyzed over time. We demonstrated that NTP-generated RNS and H2O2 were stable in PBS but scavenged by different components of the blood. While RNS remained stable in BP after initial scavenging effects, it was completely reduced in processed whole blood. On the other hand, H2O2 was completely scavenged in both liquids over time. Our previously developed luminescent probe europium(III) was used for precision measurement of ONOO− concentration. NTP-generated ONOO− was detected in all three liquids for up to at least 30 seconds, thus highlighting its therapeutic potential. Based on our results, we discussed the necessary considerations to choose the most optimal NTP modality for delivery of ROS/RNS to and via blood in the clinical context.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 4.593
DOI: 10.1155/2020/9750206
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“Effect of process parameters on the photocatalytic soot degradation on self-cleaning cementitious materials”. Smits M, Huygh D, Craeye B, Lenaerts S, Catalysis today 230, 250 (2014). http://doi.org/10.1016/J.CATTOD.2013.10.001
Abstract: Soot deposition has the negative ability to devalue the aesthetic appearance of buildings. Titanium dioxide applied on the building material is one way to counteract this problem as it provides air-purifying and self-cleaning properties due to its photocatalytic activity. In literature, photocatalytic soot oxidation was described, but until now, little information was available about the influence of process parameters on the photocatalytic degradation efficiency. The influence of three process parameters was tested in this study, namely TiO2 concentration, soot concentration and water-to-cement ratio (WIC-ratio) of the mortar substrates. The results revealed 50 mu gTiO(2) cm(-2) is better to use on the cementitious materials than 250 mu gTiO(2) cm(-2). The soot concentrations occurring in real-world situations will not inhibit the photocatalyst to be activated by light. Furthermore, the photonic efficiency increases slightly for lower WIC-ratios. This can be of interest for structural building applications, since a lower WIC-ratio results in a lower porosity of the samples and consequently in an increase in mortar strength. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL); Energy and Materials in Infrastructure and Buildings (EMIB)
Impact Factor: 4.636
Times cited: 14
DOI: 10.1016/J.CATTOD.2013.10.001
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“Cold Atmospheric Plasma Does Not Affect Stellate Cells Phenotype in Pancreatic Cancer Tissue in Ovo”. Privat-Maldonado A, Verloy R, Cardenas Delahoz E, Lin A, Vanlanduit S, Smits E, Bogaerts A, International Journal Of Molecular Sciences 23, 1954 (2022). http://doi.org/10.3390/ijms23041954
Abstract: Pancreatic ductal adenocarcinoma (PDAC) is a challenging neoplastic disease, mainly due to the development of resistance to radio- and chemotherapy. Cold atmospheric plasma (CAP) is an alternative technology that can eliminate cancer cells through oxidative damage, as shown in vitro, in ovo, and in vivo. However, how CAP affects the pancreatic stellate cells (PSCs), key players in the invasion and metastasis of PDAC, is poorly understood. This study aims to determine the effect of an anti-PDAC CAP treatment on PSCs tissue developed in ovo using mono- and co-cultures of RLT-PSC (PSCs) and Mia PaCa-2 cells (PDAC). We measured tissue reduction upon CAP treatment and mRNA expression of PSC activation markers and extracellular matrix (ECM) remodelling factors via qRT-PCR. Protein expression of selected markers was confirmed via immunohistochemistry. CAP inhibited growth in Mia PaCa-2 and co-cultured tissue, but its effectiveness was reduced in the latter, which correlates with reduced ki67 levels. CAP did not alter the mRNA expression of PSC activation and ECM remodelling markers. No changes in MMP2 and MMP9 expression were observed in RLT-PSCs, but small changes were observed in Mia PaCa-2 cells. Our findings support the ability of CAP to eliminate PDAC cells, without altering the PSCs.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 5.6
DOI: 10.3390/ijms23041954
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“Physical plasma-derived oxidants sensitize pancreatic cancer cells to ferroptotic cell death”. Kumar N, Perez-Novo C, Shaw P, Logie E, Privat-Maldonado A, Dewilde S, Smits E, Berghe WV, Bogaerts A, Free Radical Biology And Medicine 166, 187 (2021). http://doi.org/10.1016/j.freeradbiomed.2021.02.026
Abstract: Despite modern therapeutic advances, the survival prospects of pancreatic cancer patients remain poor, due to chemoresistance and dysregulated oncogenic kinase signaling networks. We applied a novel kinome activitymapping approach using biological peptide targets as phospho-sensors to identify vulnerable kinase dependencies for therapy sensitization by physical plasma. Ser/Thr-kinome specific activity changes were mapped upon induction of ferroptotic cell death in pancreatic tumor cells exposed to reactive oxygen and nitrogen species of plasma-treated water (PTW). This revealed a broad kinome activity response involving the CAMK, the AGC and CMGC family of kinases. This systems-level kinome network response supports stress adaptive switches between chemoresistant anti-oxidant responses of Kelch-like ECH-associated protein 1 (KEAP1)/Heme Oxygenase 1 (HMOX1) and ferroptotic cell death sensitization upon suppression of Nuclear factor (erythroid derived 2)-like 2 (NRF2) and Glutathione peroxidase 4 (GPX4). This is further supported by ex vivo experiments in the chicken chorioallantoic membrane assay, showing decreased GPX4 and Glutathione (GSH) expression as well as increased lipid peroxidation, along with suppressed BxPC-3 tumor growth in response to PTW. Taken all together, we demonstrate that plasma treated water-derived oxidants sensitize pancreatic cancer cells to ferroptotic cell death by targeting a NRF2-HMOX1-GPX4 specific kinase signaling network.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 5.606
DOI: 10.1016/j.freeradbiomed.2021.02.026
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“Photocatalytic process optimisation for ethylene oxidation”. Tytgat T, Hauchecorne B, Abakumov AM, Smits M, Verbruggen SW, Lenaerts S, Chemical engineering journal 209, 494 (2012). http://doi.org/10.1016/j.cej.2012.08.032
Abstract: When studying photocatalysis it is important to consider, beside the chemical approach, the engineering part related to process optimisation. To achieve this a fixed bed photocatalytic set-up consisting of different catalyst placings, in order to vary catalyst distribution, is studied. The use of a fixed quantity of catalyst placed packed or randomly distributed in the reactor, results in an almost double degradation for the distributed catalyst. Applying this knowledge leads to an improved performance with limited use of catalyst. A reactor only half filled with catalyst leads to higher degradation performance compared to a completely filled reactor. Taking into account this simple process optimisation by better distributing the catalyst a more sustainable photocatalytic air purification process is achieved. (C) 2012 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.216
Times cited: 12
DOI: 10.1016/j.cej.2012.08.032
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“The benefit of glass bead supports for efficient gas phase photocatalysis : case study of a commercial and a synthesised photocatalyst”. Verbruggen SW, Ribbens S, Tytgat T, Hauchecorne B, Smits M, Meynen V, Cool P, Martens JA, Lenaerts S, Chemical engineering journal 174, 318 (2011). http://doi.org/10.1016/J.CEJ.2011.09.038
Abstract: In the field of photocatalytic air purification, the immobilisation of catalyst particles on support surfaces without loss of photon efficiency is an important challenge. Therefore, an immobilisation method involving a one-step suspension coating of pre-synthesised photocatalysts on glass beads was applied. The various benefits are exemplified in the gas phase photodegradation of ethylene. Coating of glass beads is easy, fast, cheap and offers a more efficient alternative to bulk catalyst pellets. Furthermore, this coating procedure allows to use porous, pre-synthesised catalysts to their full potential, as the surface area and morphology of the initial powder is barely altered after coating, in strong contrast to pelletising. With this technique it became possible to study the gas phase photocatalytic activity of commercial titanium dioxide, trititanate nanotubes and mixed phase anatase/trititanate nanotubes in a packed bed reactor towards the degradation of ethylene without changing the catalyst properties. Coating of glass beads with the photocatalyst revealed the superior activity of the as-prepared nanotubes, compared to TiO2 Aerolyst® 7710 in gaseous phase.
Keywords: A1 Journal article; Engineering sciences. Technology; Laboratory of adsorption and catalysis (LADCA); Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.216
Times cited: 39
DOI: 10.1016/J.CEJ.2011.09.038
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“Photocatalytic degradation of soot deposition : self-cleaning effect on titanium dioxide coated cementitious materials”. Smits M, Chan C kit, Tytgat T, Craeye B, Costarramone N, Lacombe S, Lenaerts S, Chemical engineering journal 222, 411 (2013). http://doi.org/10.1016/J.CEJ.2013.02.089
Abstract: Diesel soot emissions deteriorate the appearance of architectural building materials by soot fouling. This soot deposition devalue the aesthetic value of the building. A solution to counteract this problem is applying titanium dioxide on building materials. TiO2 can provide air-purifying and self-cleaning properties due to its photocatalytic activity. In literature, photocatalytic soot oxidation is observed on glass or silicon substrates. However, degradation of soot by photocatalysis was not yet investigated on cementitious samples (mortar, concrete) although it is one of the most frequently used building materials. In this study, photocatalytic soot oxidation by means of TiO2 coated cementitious samples is addressed. The soot removal capacity of four types of TiO2 layers, coated on mortar samples, is evaluated by means of two detection methods. The first method is based on colorimetric measurements, while the second method uses digital image processing to calculate the area of soot coverage. The experimental data revealed that cementitious materials coated with commercially available TiO2 exhibited self-cleaning properties as it was found that all coated samples were able to remove soot. The P25 coating gave the best soot degradation performance, while the Eoxolit product showed the slowest soot degradation rate. In addition, gas chromatography measurements in a closed chamber experiment with P25 confirmed that complete mineralization of about 60% of the soot was obtained within 24 hours since CO2 was the sole observed oxidation product. Due to its realistic approach, this study proves that photocatalytic soot removal on TiO2 coated cementitious surfaces is possible in practice, which is an important step towards the practical application of self-cleaning building materials.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.216
Times cited: 43
DOI: 10.1016/J.CEJ.2013.02.089
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“Oxidative damage to hyaluronan–CD44 interactions as an underlying mechanism of action of oxidative stress-inducing cancer therapy”. Yusupov M, Privat-Maldonado A, Cordeiro RM, Verswyvel H, Shaw P, Razzokov J, Smits E, Bogaerts A, Redox Biology 43, 101968 (2021). http://doi.org/10.1016/j.redox.2021.101968
Abstract: Multiple cancer therapies nowadays rely on oxidative stress to damage cancer cells. Here we investigated the biological and molecular effect of oxidative stress on the interaction between CD44 and hyaluronan (HA), as interrupting their binding can hinder cancer progression. Our experiments demonstrated that the oxidation of HA decreased its recognition by CD44, which was further enhanced when both CD44 and HA were oxidized. The reduction of CD44–HA binding negatively affected the proliferative state of cancer cells. Our multi-level atomistic simulations revealed that the binding free energy of HA to CD44 decreased upon oxidation. The effect of HA and CD44 oxidation on CD44–HA binding was similar, but when both HA and CD44 were oxidized, the effect was much larger, in agreement with our experiments. Hence, our experiments and computations support our hypothesis on the role of oxidation in the disturbance of CD44–HA interaction, which can lead to the inhibition of proliferative signaling pathways inside the tumor cell to induce cell death.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 6.337
DOI: 10.1016/j.redox.2021.101968
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“OrBITS : label-free and time-lapse monitoring of patient derived organoids for advanced drug screening”. Deben C, Cardenas De La Hoz E, Le Compte M, Van Schil P, Hendriks JMH, Lauwers P, Yogeswaran SK, Lardon F, Pauwels P, van Laere S, Bogaerts A, Smits E, Vanlanduit S, Lin A, Cellular Oncology (2211-3428) , 1 (2022). http://doi.org/10.1007/S13402-022-00750-0
Abstract: Background Patient-derived organoids are invaluable for fundamental and translational cancer research and holds great promise for personalized medicine. However, the shortage of available analysis methods, which are often single-time point, severely impede the potential and routine use of organoids for basic research, clinical practise, and pharmaceutical and industrial applications. Methods Here, we developed a high-throughput compatible and automated live-cell image analysis software that allows for kinetic monitoring of organoids, named Organoid Brightfield Identification-based Therapy Screening (OrBITS), by combining computer vision with a convolutional network machine learning approach. The OrBITS deep learning analysis approach was validated against current standard assays for kinetic imaging and automated analysis of organoids. A drug screen of standard-of-care lung and pancreatic cancer treatments was also performed with the OrBITS platform and compared to the gold standard, CellTiter-Glo 3D assay. Finally, the optimal parameters and drug response metrics were identified to improve patient stratification. Results OrBITS allowed for the detection and tracking of organoids in routine extracellular matrix domes, advanced Gri3D (R)-96 well plates, and high-throughput 384-well microplates, solely based on brightfield imaging. The obtained organoid Count, Mean Area, and Total Area had a strong correlation with the nuclear staining, Hoechst, following pairwise comparison over a broad range of sizes. By incorporating a fluorescent cell death marker, infra-well normalization for organoid death could be achieved, which was tested with a 10-point titration of cisplatin and validated against the current gold standard ATP-assay, CellTiter-Glo 3D. Using this approach with OrBITS, screening of chemotherapeutics and targeted therapies revealed further insight into the mechanistic action of the drugs, a feature not achievable with the CellTiter-Glo 3D assay. Finally, we advise the use of the growth rate-based normalised drug response metric to improve accuracy and consistency of organoid drug response quantification. Conclusion Our findings validate that OrBITS, as a scalable, automated live-cell image analysis software, would facilitate the use of patient-derived organoids for drug development and therapy screening. The developed wet-lab workflow and software also has broad application potential, from providing a launching point for further brightfield-based assay development to be used for fundamental research, to guiding clinical decisions for personalized medicine.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Center for Oncological Research (CORE)
Impact Factor: 6.6
DOI: 10.1007/S13402-022-00750-0
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“Oxidative Stress-Inducing Anticancer Therapies: Taking a Closer Look at Their Immunomodulating Effects”. Van Loenhout J, Peeters M, Bogaerts A, Smits E, Deben C, Antioxidants 9, 1188 (2020). http://doi.org/10.3390/antiox9121188
Abstract: Cancer cells are characterized by higher levels of reactive oxygen species (ROS) compared to normal cells as a result of an imbalance between oxidants and antioxidants. However, cancer cells maintain their redox balance due to their high antioxidant capacity. Recently, a high level of oxidative stress is considered a novel target for anticancer therapy. This can be induced by increasing exogenous ROS and/or inhibiting the endogenous protective antioxidant system. Additionally, the immune system has been shown to be a significant ally in the fight against cancer. Since ROS levels are important to modulate the antitumor immune response, it is essential to consider the effects of oxidative stress-inducing treatments on this response. In this review, we provide an overview of the mechanistic cellular responses of cancer cells towards exogenous and endogenous ROS-inducing treatments, as well as the indirect and direct antitumoral immune effects, which can be both immunostimulatory and/or immunosuppressive. For future perspectives, there is a clear need for comprehensive investigations of different oxidative stress-inducing treatment strategies and their specific immunomodulating effects, since the effects cannot be generalized over different treatment modalities. It is essential to elucidate all these underlying immune effects to make oxidative stress-inducing treatments effective anticancer therapy.
Keywords: A1 Journal article; Pharmacology. Therapy; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 7
DOI: 10.3390/antiox9121188
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“Inactivation of SARS-CoV-2 and other enveloped and non-enveloped viruses with non-thermal plasma for hospital disinfection”. Sahun M, Privat-Maldonado A, Lin A, De Roeck N, Van de Heyden L, Hillen M, Michiels J, Steenackers G, Smits E, Ariën KK, Jorens PG, Delputte P, Bogaerts A, ACS Sustainable Chemistry and Engineering , 1 (2023). http://doi.org/10.1021/ACSSUSCHEMENG.2C07622
Abstract: As recently highlighted by the SARS-CoV-2 pandemic, viruses have become an increasing burden for health, global economy, and environment. The control of transmission by contact with contaminated materials represents a major challenge, particularly in hospital environments. However, the current disinfection methods in hospital settings suffer from numerous drawbacks. As a result, several medical supplies that cannot be properly disinfected are not reused, leading to severe shortages and increasing amounts of waste, thus prompting the search for alternative solutions. In this work, we report that non-thermal plasma (NTP) can effectively inactivate SARS-CoV-2 from non-porous and porous materials commonly found in healthcare facilities. We demonstrated that 5 min treatment with a dielectric barrier discharge NTP can inactivate 100% of SARS-CoV-2 (Wuhan and Omicron strains) from plastic material. Using porcine respiratory coronavirus (surrogate for SARS-CoV-2) and coxsackievirus B3 (highly resistant non-enveloped virus), we tested the NTP virucidal activity on hospital materials and obtained complete inactivation after 5 and 10 min, respectively. We hypothesize that the produced reactive species and local acidification contribute to the overall virucidal effect of NTP. Our results demonstrate the potential of dielectric barrier discharge NTPs for the rapid, efficient, and low-cost disinfection of healthcare materials.
Keywords: A1 Journal article; Engineering sciences. Technology; Center for Oncological Research (CORE); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Laboratory Experimental Medicine and Pediatrics (LEMP)
Impact Factor: 8.4
DOI: 10.1021/ACSSUSCHEMENG.2C07622
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“Non‐Thermal Plasma as a Unique Delivery System of Short‐Lived Reactive Oxygen and Nitrogen Species for Immunogenic Cell Death in Melanoma Cells”. Lin A, Gorbanev Y, De Backer J, Van Loenhout J, Van Boxem W, Lemière F, Cos P, Dewilde S, Smits E, Bogaerts A, Advanced Science 6, 1802062 (2019). http://doi.org/10.1002/advs.201802062
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 9.034
Times cited: 39
DOI: 10.1002/advs.201802062
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“Photocatalytic degradation of ethylene : an FTIR in situ study under atmospheric conditions”. Hauchecorne B, Tytgat T, Verbruggen SW, Hauchecorne D, Terrens D, Smits M, Vinken K, Lenaerts S, Applied catalysis : B : environmental 105, 111 (2011). http://doi.org/10.1016/J.APCATB.2011.03.041
Abstract: In this paper, the reaction mechanism of the photocatalytic oxidation of ethylene is elucidated by means of an in-house developed FTIR in situ reactor. This reactor allowed us to look at the catalytic surface at the moment the reactions actually occur. This new approach gave some exciting new insights in how ethylene is photocatalytically oxidised. It was found that there is a change in dipole moment of the ethylene molecule when it is brought in the neighbourhood of the catalyst. From this finding, a hypothesis was formulated on how the CC-bond from ethylene will break. It was found that the aforementioned interaction between the catalyst and the molecule, allows the excited electrons from the UV irradiated catalyst to occupy the lowest unoccupied molecular orbital (LUMO) of the ethylene molecule through a process known as backdonation. Following this hypothesis, it was found that the degradation occurs through the formation of two intermediates: formaldehyde and formic acid, for which formaldehyde is bound in two different ways (coordinatively and as bidentate). Finally CO2 and H2O are found as end products, resulting in the complete mineralisation of the pollutant.
Keywords: A1 Journal article; Engineering sciences. Technology; Molecular Spectroscopy (MolSpec); Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 9.446
Times cited: 29
DOI: 10.1016/J.APCATB.2011.03.041
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“The pro- and anti-tumoral properties of gap junctions in cancer and their role in therapeutic strategies”. Oliveira MC, Verswyvel H, Smits E, Cordeiro RM, Bogaerts A, Lin A, Redox Biology 57, 102503 (2022). http://doi.org/10.1016/j.redox.2022.102503
Abstract: Gap junctions (GJs), essential structures for cell-cell communication, are made of two hemichannels (commonly called connexons), one on each adjacent cell. Found in almost all cells, GJs play a pivotal role in many physiological and cellular processes, and have even been linked to the progression of diseases, such as cancer. Modulation of GJs is under investigation as a therapeutic strategy to kill tumor cells. Furthermore, GJs have also been studied for their key role in activating anti-cancer immunity and propagating radiation- and oxidative stress-induced cell death to neighboring cells, a process known as the bystander effect. While, gap junction (GJ)based therapeutic strategies are being developed, one major challenge has been the paradoxical role of GJs in both tumor progression and suppression, based on GJ composition, cancer factors, and tumoral context. Therefore, understanding the mechanisms of action, regulation, and the dual characteristics of GJs in cancer is critical for developing effective therapeutics. In this review, we provide an overview of the current under standing of GJs structure, function, and paradoxical pro- and anti-tumoral role in cancer. We also discuss the treatment strategies to target these GJs properties for anti-cancer responses, via modulation of GJ function.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 11.4
DOI: 10.1016/j.redox.2022.102503
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Debie Y, van Audenaerde JRM, Vandamme T, Croes L, Teuwen L-A, Verbruggen L, Vanhoutte G, Marcq E, Verheggen L, Le Blon D, Peeters B, Goossens M, Pannus P, Arië,n KK, Anguille S, Janssens A, Prenen H, Smits ELJ, Vulsteke C, Lion E, Peeters M, Van Dam PA (2023) Humoral and cellular immune responses against SARS-CoV-2 after third dose BNT162b2 following double-dose vaccination with BNT162b2 versus ChAdOx1 in patients with cancer. 635–646
Abstract: Purpose: Patients with cancer display reduced humoral responses after double-dose COVID-19 vaccination, whereas their cellular response is more comparable with that in healthy individuals. Recent studies demonstrated that a third vaccination dose boosts these immune responses, both in healthy people and patients with cancer. Because of the availability of many different COVID-19 vaccines, many people have been boosted with a different vaccine fromthe one used for double-dose vaccination. Data on such alternative vaccination schedules are scarce. This prospective study compares a third dose of BNT162b2 after double-dose BNT162b2 (homologous) versus ChAdOx1 (heterologous) vaccination in patients with cancer. Experimental Design: A total of 442 subjects (315 patients and 127 healthy) received a third dose of BNT162b2 (230 homologous vs. 212 heterologous). Vaccine-induced adverse events (AE) were captured up to 7 days after vaccination. Humoral immunity was assessed by SARS-CoV-2 anti-S1 IgG antibody levels and SARSCoV- 2 50% neutralization titers (NT50) against Wuhan and BA.1 Omicron strains. Cellular immunity was examined by analyzing CD4þ and CD8þ T-cell responses against SARS-CoV-2–specific S1 and S2 peptides. Results: Local AEs were more common after heterologous boosting. SARS-CoV-2 anti-S1 IgG antibody levels did not differ significantly between homologous and heterologous boosted subjects [GMT 1,755.90 BAU/mL (95% CI, 1,276.95–2,414.48) vs. 1,495.82 BAU/mL (95% CI, 1,131.48–1,977.46)]. However, homologous- boosted subjects show significantly higher NT50 values against BA.1 Omicron. Subjects receiving heterologous boosting demonstrated increased spike-specific CD8þ T cells, including higher IFNg and TNFa levels. Conclusions: In patients with cancer who received double-dose ChAdOx1, a third heterologous dose of BNT162b2 was able to close the gap in antibody response.
Keywords: University Hospital Antwerp; A1 Journal article; Laboratory for Experimental Hematology (LEH); Center for Oncological Research (CORE)
Impact Factor: 11.5
DOI: 10.1158/1078-0432.CCR-22-2185
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“Injectable Plasma‐Treated Alginate Hydrogel for Oxidative Stress Delivery to Induce Immunogenic Cell Death in Osteosarcoma”. Živanić, M, Espona‐Noguera A, Verswyvel H, Smits E, Bogaerts A, Lin A, Canal C, Advanced functional materials (2023). http://doi.org/10.1002/adfm.202312005
Abstract: Cold atmospheric plasma (CAP) is a source of cell‐damaging oxidant molecules that may be used as low‐cost cancer treatment with minimal side effects. Liquids treated with cold plasma and enriched with oxidants are a modality for non‐invasive treatment of internal tumors with cold plasma via injection. However, liquids are easily diluted with body fluids which impedes high and localized delivery of oxidants to the target. As an alternative, plasma‐treated hydrogels (PTH) emerge as vehicles for the precise delivery of oxidants. This study reports an optimal protocol for the preparation of injectable alginate PTH that ensures the preservation of plasma‐generated oxidants. The generation, storage, and release of oxidants from the PTH are assessed. The efficacy of the alginate PTH in cancer treatment is demonstrated in the context of cancer cell cytotoxicity and immunogenicity–release of danger signals and phagocytosis by immature dendritic cells, up to now unexplored for PTH. These are shown in osteosarcoma, a hard‐to‐treat cancer. The study aims to consolidate PTH as a novel cold plasma treatment modality for non‐invasive or postoperative tumor treatment. The results offer a rationale for further exploration of alginate‐based PTHs as a versatile platform in biomedical engineering.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 19
DOI: 10.1002/adfm.202312005
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“Acquired non-thermal plasma resistance mediates a shift towards aerobic glycolysis and ferroptotic cell death in melanoma”. Lin A, Sahun M, Biscop E, Verswyvel H, De Waele J, De Backer J, Theys C, Cuypers B, Laukens K, Berghe WV, Smits E, Bogaerts A, Drug resistance updates 67, 100914 (2023). http://doi.org/10.1016/j.drup.2022.100914
Abstract: To gain insights into the underlying mechanisms of NTP therapy sensitivity and resistance, using the firstever
NTP-resistant cell line derived from sensitive melanoma cells (A375).
Methods: Melanoma cells were exposed to NTP and re-cultured for 12 consecutive weeks before evaluation
against the parental control cells. Whole transcriptome sequencing analysis was performed to identify differentially
expressed genes and enriched molecular pathways. Glucose uptake, extracellular lactate, media acidification,
and mitochondrial respiration was analyzed to determine metabolic changes. Cell death inhibitors were
used to assess the NTP-induced cell death mechanisms, and apoptosis and ferroptosis was further validated via
Annexin V, Caspase 3/7, and lipid peroxidation analysis.
Results: Cells continuously exposed to NTP became 10 times more resistant to NTP compared to the parental cell
line of the same passage, based on their half-maximal inhibitory concentration (IC50). Sequencing and metabolic
analysis indicated that NTP-resistant cells had a preference towards aerobic glycolysis, while cell death analysis
revealed that NTP-resistant cells exhibited less apoptosis but were more vulnerable to lipid peroxidation and
ferroptosis.
Conclusions: A preference towards aerobic glycolysis and ferroptotic cell death are key physiological changes in
NTP-resistance cells, which opens new avenues for further, in-depth research into other cancer types.
Keywords: A1 Journal article; Pharmacology. Therapy; ADReM Data Lab (ADReM); Center for Oncological Research (CORE); Proteinscience, proteomics and epigenetic signaling (PPES); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 24.3
DOI: 10.1016/j.drup.2022.100914
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