A. Cheruvathoor Poulose, G. Zoppellaro, I. Konidakis, E. Serpetzoglou, E. Stratakis, O. Tomanec, M. Beller, A. Bakandritsos and R. Zbořil, "Reply to: Primary role of photothermal heating in light-driven reduction of nitroarenes," NATURE NANOTECHNOLOGY, vol. 18, iss. 4, pp. 327-328, 2023.
DOI: 10.1038/s41565-023-01353-y, IF = 40.523
A. Cheruvathoor Poulose, M. Medveď, V. R. Bakuru, A. Sharma, D. Singh, S. B. Kalidindi, H. Bares, M. Otyepka, K. Jayaramulu, A. Bakandritsos and R. Zbořil, "Acidic graphene organocatalyst for the superior transformation of wastes into high-added-value chemicals," NATURE COMMUNICATIONS, vol. 14, pp. 1373, 2023.
DOI: 10.1038/s41467-023-36602-0, IF = 14.919
Abstract: Our dependence on finite fossil fuels and the insecure energy supply chains have stimulated intensive research for sustainable technologies. Upcycling glycerol, produced from biomass fermentation and as a biodiesel formation byproduct, can substantially contribute in circular carbon economy. Here, we report glycerol’s solvent-free and room-temperature conversion to high-added-value chemicals via a reusable graphene catalyst (G-ASA), functionalized with a natural amino acid (taurine). Theoretical studies unveil that the superior performance of the catalyst (surpassing even homogeneous, industrial catalysts) is associated with the dual role of the covalently linked taurine, boosting the catalyst’s acidity and affinity for the reactants. Unlike previous catalysts, G-ASA exhibits excellent activity (7508 mmol g−1 h−1) and selectivity (99.9%) for glycerol conversion to solketal, an additive for improving fuels’ quality and a precursor of commodity and fine chemicals. Notably, the catalyst is also particularly active in converting oils to biodiesel, demonstrating its general applicability.
I. Tantis, S. Talande, V. Tzitzios, G. Basina, V. Shrivastav, A. Bakandritsos and R. Zboril, "Non‐van der Waals 2D Materials for Electrochemical Energy Storage," ADVANCED FUNCTIONAL MATERIALS, Article in press, 2023.
DOI: 10.1002/adfm.202209360, IF = 19.924
Abstract: The development of advanced electrode materials for the next generation of electrochemical energy storage (EES) solutions has attracted profound research attention as a key enabling technology toward decarbonization and electrification of transportation. Since the discovery of graphene's remarkable properties, 2D nanomaterials, derivatives, and heterostructures thereof, have emerged as some of the most promising electrode components in batteries and supercapacitors owing to their unique and tunable physical, chemical, and electronic properties, commonly not observed in their 3D counterparts. This review particularly focuses on recent advances in EES technologies related to 2D crystals originating from non-layered 3D solids (non-van der Waals; nvdW) and their hallmark features pertaining to this field of application. Emphasis is given to the methods and challenges in top-down and bottom-up strategies toward nvdW 2D sheets and their influence on the materials’ features, such as charge transport properties, functionalization, or adsorption dynamics. The exciting advances in nvdW 2D-based electrode materials of different compositions and mechanisms of operation in EES are discussed. Finally, the opportunities and challenges of nvdW 2D systems are highlighted not only in electrochemical energy storage but also in other applications, including spintronics, magnetism, and catalysis.
S. Rej, E. Y. Santiago, O. Baturina, Y. Zhang, S. Burger, S. Kment, A. O. Govorov and A. Naldoni, "Colloidal titanium nitride nanobars for broadband inexpensive plasmonics and photochemistry from visible to mid-IR wavelengths," NANO ENERGY, vol. 104, iss. , pp. 107989, 2023.
DOI: 10.1016/j.nanoen.2022.107989, IF = 19.069
Abstract: Developing colloidal plasmonic nanomaterials with high carrier density that show optical resonances and photochemical activity extending from the visible to the mid-infrared (MIR) ranges remains a challenging pursuit. Here, we report the fabrication of titanium nitride (TiN) nanobars obtained using a two–step procedure based on a wet chemical route synthesis of TiO2 nanowires and their subsequent high temperature annealing in ammonia flow. Electromagnetic simulations of the resulting TiN nanobars reveal a rich set of optical resonances featuring transverse, longitudinal and mixed transverse–longitudinal plasmonic modes that cover energies from the visible to MIR region. TiN nanobars decorated with Pt co-catalyst nanocrystals show enhanced photocatalytic hydrogen evolution activity in comparison to both isotropic TiN nanospheres of similar size and TiN nanocubes under near infrared excitation at 940 nm due to the enhanced hot electron generation. We also demonstrate that plasmonic TiN nanobars can be used for the detection of furfural molecular vibrations by providing a strong surface enhanced infrared absorption (SEIRA) effect in the MIR region.
M. Xie, M. Gao, Y. Yun, M. Malmsten, V. M. Rotello, R. Zboril, O. Akhavan, A. Kraskouski, J. Amalraj, X. Cai, J. Lu, H. Zheng and R. Li, "Antibacterial Nanomaterials: Mechanisms, Impacts on Antimicrobial Resistance and Design Principles," ANGEWANDTE CHEMIE INTERNATIONAL EDITION, vol. 62, iss. 17, pp. e202217345, 2023.
DOI: 10.1002/anie.202217345, IF = 16.823
Abstract: Antimicrobial resistance (AMR) is one of the biggest threats to the environment and health. AMR rapidly invalidates conventional antibiotics, and antimicrobial nanomaterials have been increasingly explored as alternatives. Interestingly, several antimicrobial nanomaterials show AMR-independent antimicrobial effects without detectable new resistance and have therefore been suggested to prevent AMR evolution. In contrast, some are found to trigger the evolution of AMR. Given these seemingly conflicting findings, a timely discussion of the two faces of antimicrobial nanomaterials is urgently needed. This review systematically compares the killing mechanisms and structure-activity relationships of antibiotics and antimicrobial nanomaterials. We then focus on nano-microbe interactions to elucidate the impacts of molecular initiating events on AMR evolution. Finally, we provide an outlook on future antimicrobial nanomaterials and propose design principles for the prevention of AMR evolution.
J. M. R. Flauzino, M. Nalepa, D. D. Chronopoulos, V. Šedajová, D. Panáček, P. Jakubec, P. Kührová, M. Pykal, P. Banáš, A. Panáček, A. Bakandritsos and M. Otyepka, "Click and Detect: Versatile Ampicillin Aptasensor Enabled by Click Chemistry on a Graphene–Alkyne Derivative," SMALL, Article in press, 2023.
DOI: 10.1002/smll.202207216, IF = 15.153
Abstract: Tackling the current problem of antimicrobial resistance (AMR) requires fast, inexpensive, and effective methods for controlling and detecting antibiotics in diverse samples at the point of interest. Cost-effective, disposable, point-of-care electrochemical biosensors are a particularly attractive option. However, there is a need for conductive and versatile carbon-based materials and inks that enable effective bioconjugation under mild conditions for the development of robust, sensitive, and selective devices. This work describes a simple and fast methodology to construct an aptasensor based on a novel graphene derivative equipped with alkyne groups prepared via fluorographene chemistry. Using click chemistry, an aptamer is immobilized and used as a successful platform for the selective determination of ampicillin in real samples in the presence of interfering molecules. The electrochemical aptasensor displayed a detection limit of 1.36 nM, high selectivity among other antibiotics, the storage stability of 4 weeks, and is effective in real samples. Additionally, structural and docking simulations of the aptamer shed light on the ampicillin binding mechanism. The versatility of this platform opens up wide possibilities for constructing a new class of aptasensor based on disposable screen-printed carbon electrodes usable in point-of-care devices.
T. Malina, C. Hirsch, A. Rippl, D. Panacek, K. Polakova, V. Sedajova, M. Scheibe, R. Zboril and P. Wick, "Safety assessment of graphene acid and cyanographene: Towards new carbon-based nanomedicine," CARBON, vol. 211, pp. 118093, 2023.
DOI: 10.1016/j.carbon.2023.118093, IF = 11.307
Abstract: Graphene oxide (GO) has been intensively studied in last decades as a promising delivery nanoplatform. Although it surpasses the pristine graphene in its hydrophilic properties, variability in GO syntheses and chemical composition, its non-specific surface properties and heterogeneity in colloidal stability hamper its commercial application in general. Reliable cytotoxicity investigation of new nanotherapeutics under relevant physiological conditions represents an indispensable first step for their potential clinical translation. In the case of delivery nanoplatforms, the vasculature represents the first encounter after intravenous application. Therefore, an evaluation of interaction with endothelial and immune cells is highly desirable. Here, we performed a first comprehensive safety assessment of emerging graphene derivatives with high potential in biomedical technologies: graphene acid (GA) and cyanographene (GCN). We utilized an easy-to-use co-culture model of matured human umbilical vein endothelial cells (HUVECs) and a human monocyte/macrophage like cell line (THP-1) under dynamic flow conditions. An environment that has not been used yet to evaluate any graphene material. Our results demonstrate that well-defined synthesis/structure of GA and GCN overcome some drawbacks of graphene oxide (GO), the benchmark graphene derivative. Furthermore, applying a system mimicking a simplified blood vessel, both GA and GCN showed excellent biocompatibility without any indication of acute inflammation or dysfunction of endothelium. In summary, GA and GCN display so far all desirable properties to be potentially utilized in drug/gene delivery applications compared to the conventional GO.
Q. Yang, E. Nguyen, D. Panáček, V. Šedajová, V. Hrubý, G. Rosati, C. de C. C. Silva, A. Bakandritsos, M. Otyepka and A. Merkoçi, "Metal-free cysteamine-functionalized graphene alleviates mutual interferences in heavy metal electrochemical detection," CHEMICAL REVIEWS, Article in press, 2023.
DOI: 10.1039/D2GC02978B, IF = 11.034
Abstract: Heavy metal pollutants are of great concern to environmental monitoring due to their potent toxicity. Electrochemical detection, one of the main techniques, is hindered by the mutual interferences of various heavy metal ions in practical use. In particular, the sensitivity of carbon electrodes to Cd2+ ions (one of the most toxic heavy metals) is often overshadowed by some heavy metals (e.g. Pb2+ and Cu2+). To mitigate interference, metallic particles/films (e.g. Hg, Au, Bi, and Sn) typically need to be embedded in the carbon electrodes. However, these additional metallic materials may face issues of secondary pollution and unsustainability. In this study, a metal-free and sustainable nanomaterial, namely cysteamine covalently functionalized graphene (GSH), was found to lead to a 6-fold boost in the Cd2+ sensitivity of the screen-printed carbon electrode (SPCE), while the sensitivities to Pb2+ and Cu2+ were not influenced in simultaneous detection. The selective enhancement could be attributed to the grafted thiols on GSH sheets with good affinity to Cd2+ ions based on Pearson's hard and soft acid and base principle. More intriguingly, the GSH-modified SPCE (GSH-SPCE) featured high reusability with extended cycling times (23 times), surpassing the state-of-art SPCEs modified by non-covalently functionalized graphene derivatives. Last, the GSH-SPCE was validated in tap water.
M. Langer, L. Zdražil, M. Medved and M. Otyepka, "Communication of Molecular Fluorophores with Other Photoluminescence Centres in Carbon Dots," NANOSCALE, Article in press, 2023.
DOI: 10.1039/d2nr05114a, IF = 8.307
The establishment of structure-photoluminescence (PL) relationships remains an ultimate challenge in the field of carbon dots (CDs). It is now commonly understood that various structural domains may evolve during the preparation of CDs; nonetheless, we are still far from capturing the specific features that determine the overall PL of CDs. Although the core, surface and molecular states are usually considered the three main sources of PL, it is not known to which extent they interact and/or affect one another. Expectedly, the communication between the different PL centres depends on the mutual arrangement and the type of linking. To gain insights into such a communication, time-dependent density functional theory (TD-DFT) calculations were performed for several (N-doped/O-functionalized) polyaromatic hydrocarbons (PAHs) as representative models for the core/surfaces PL states and the prototypical molecular fluorophore (MF) 5-oxo-1,2,3,5-tetrahydroimidazo-[1,2-α]-pyridine-7-carboxylic acid (IPCA), considering different interaction modes, namely hydrogen bonded and stacked complexes as well as covalently bonded and fused structures. Our results revealed that each of the studied arrangements in some way supported the communication between the PL centres. The deactivation pathways typically involve multiple charge and energy transfer events that can promote the formation of charge separated states and/or lead to the activation of other PL centres in CDs. Depending on the arrangement, the doping pattern and surface functionalization, both the CD core and the MF can act as an electron donor or acceptor, which could help to design CDs with desirable hole–electron surface/core characteristics.
Z. Trávníček, T. Malina, J. Vančo, M. Šebela and Z. Dvořák, "Heteroleptic Copper(II) Complexes Containing 2′-Hydroxy-4-(Dimethylamino)Chalcone Show Strong Antiproliferative Activity," PHARMACEUTICS, vol. 15, iss. 2, pp. 307, 2023.
DOI: 10.3390/pharmaceutics15020307, IF = 6.525
Abstract: Text: A series of six heteroleptic copper(II) complexes with 2′-hydroxy-4-(dimethylamino)chalcone (HL) with the composition [Cu(N-N)(L)]NO3 (1–6), where N-N stands for dmbpy = 5,5′-dimethyl-2,2′-bipyridine (1), bphen = 4,7-diphenyl-1,10-phenanthroline (2), dbbpy = 4,4′-di-tert-butyl-2,2′-bipyridine (3), nphen = 5-nitro-1,10-phenanthroline (4), bpy = 2,2′-bipyridine, (5), and dpa = 2,2′-dipyridylamine (6), was prepared and thoroughly characterized. The in vitro cytotoxicity screening on eight human cancer cell lines identified complex 2, containing the bulkiest N-donor ligands (bphen) as highly cytotoxic against cancer cells, with IC50 values ranking from 1.0 to 2.3 μM, with good selectivity and low toxicity against healthy human fetal lung fibroblasts MRC-5. The cell-based assays, involving the most effective complex 2 in A2780 cancer cells, revealed its strong pro-apoptotic effects based on the effective activation of caspases 3/7, ROS overproduction, and autophagy in the A2780 cells while not impeding the cell cycle and mitochondrial membrane functions. The cellular uptake studies in A2780 and 22Rv1 cells uncovered no intracellular transport of the cationic complex 2, supporting the hypothesis that the in vitro anticancer effects of complex 2 are based on the combined extrinsic activation of apoptosis and autophagy induction.
Z. Trávníček, J. Vančo, J. Belza, J. Hošek, Z. Dvořák, R. Lenobel, I. Popa, K. Šmejkal and P. Uhrin, "The Gold(I) Complex with Plant Hormone Kinetin Shows Promising In Vitro Anticancer and PPARγ Properties," INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, vol. 24, iss. 3, pp. 2293, 2023.
DOI: 10.3390/ijms24032293, IF = 6.208
Abstract: Abstract Motivated by the clinical success of gold(I) metallotherapeutic Auranofin in the effective treatment of both inflammatory and cancer diseases, we decided to prepare, characterize, and further study the [Au(kin)(PPh3)] complex (1), where Hkin = kinetin, 6-furfuryladenine, for its in vitro anti-cancer and anti-inflammatory activities. The results revealed that the complex (1) had significant in vitro cytotoxicity against human cancer cell lines (A2780, A2780R, PC-3, 22Rv1, and THP-1), with IC50 ≈ 1–5 μM, which was even significantly better than that for the conventional platinum-based drug Cisplatin while comparable with Auranofin. Although its ability to inhibit transcription factor NF-κB activity did not exceed the comparative drug Auranofin, it has been found that it is able to positively influence peroxisome-proliferator-activated receptor-gamma (PPARγ), and as a consequence of this to have the impact of moderating/reducing inflammation. The cellular effects of the complex (1) in A2780 cancer cells were also investigated by cell cycle analysis, induction of apoptosis, intracellular ROS production, activation of caspases 3/7 and disruption of mitochondrial membrane potential, and shotgun proteomic analysis. Proteomic analysis of R2780 cells treated with complex (1) and starting compounds revealed possible different places of the effect of the studied compounds. Moreover, the time-dependent cellular accumulation of copper was studied by means of the mass spectrometry study with the aim of exploring the possible mechanisms responsible for its biological effects.
M. Paloncýová, M. Šrejber, P. Čechová, P. Kührová, F. Zaoral and M. Otyepka, "Atomistic Insights into Organization of RNA-Loaded Lipid Nanoparticles," THE JOURNAL OF PHYSICAL CHEMISTRY B, vol. 127, iss. 5, pp. 1158-1166, 2023.
DOI: 10.1021/acs.jpcb.2c07671, IF = 3.466
Abstract: RNA-based therapies have shown promise in a wide range of applications, from cancer therapy, treatment of inherited diseases to vaccination. Encapsulation of RNA into ionizable lipid (IL) containing lipid nanoparticles (LNPs) has enabled its safe and targeted delivery. We present here the simulations of the self-assembly process of pH-sensitive RNA-carrying LNPs and their internal morphology. At low pH, the simulations confirm a lipid core encapsulating RNA in the hexagonal phase. Our all-atom and coarse-grained simulations show that an RNA molecule inside an LNP is protected from interactions with ions by being enveloped in the charged ILs. At neutral pH, representing the environment after LNP administration into human tissues, LNPs expelled most of the encapsulated RNA and water and formed separate bulk IL-rich and ordered the helper-lipid-rich phase. Helper lipids arranged themselves to be in contact with RNA or water. The presented models provide atomistic understanding of the LNP structure and open a way to investigate them in silico, varying the LNP composition or interacting with other biostructures aiming at increasing the efficiency of RNA-based medicine.