Embargo
Testing of black-carrots-derived fluorescence imaging and anti-metastatic potential
(Elsevier, 2024) Algarra González, Manuel; Carrillo, Celia; Nesic, Maja D.; Filipovic Trickovic, Jelena; Zakula, Jelena; Koricanac, Lela; Jiménez-Jiménez, José; Rodríguez-Castellón, Enrique; Bandosz, Teresa J.; Petkovic, Marijana; Soto, Juan; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
This paper explains the basis for the excitation energy-independent fluorescence emission of biomass-derived carbon dots (CDs) and shows that these CDs have excellent anti-melanoma and anti-metastatic potential. Additionally, we demonstrate that the black carrots´-derived CDs can be exploited as cell cycle-sensing agents, because of the interaction with chromatin material. Besides their optical properties, fluorescent CDs have gained increased attention for image-guided cancer treatment due to their water solubility, environmental friendliness, affordability, ease of synthesis, and primary biocompatibility. CDs have excellent photostability, determined by their precursors and synthesis pathways. In this study, CDs with chemically homogenous surface functional groups were made using a hydrothermal technique from black carrot extract, an anthocyanin-rich substance derived from biomass. The anti-cancer and anti-metastatic properties of black carrot-derived CDs can be attributed to flavylium cations on the surface, spherical forms, and high water dispersibility. Most importantly, these CDs demonstrate a stable emission at a single wavelength, 612 nm, independent of the excitation energy, which we have explained theoretically for the first time.
Open Access
One-pot synthesis of green-emitting nitrogen-doped carbon dots from xylose
(MDPI, 2023) Rodríguez-Carballo, Gabriela; García-Sancho, Cristina; Algarra González, Manuel; Castro, Eulogio; Moreno-Tost, Ramón; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
Carbon dots (CDs) are interesting carbon nanomaterials that exhibit great photoluminescent features, low cytotoxicity, and excellent water stability and solubility. For these reasons, many fields are starting to integrate their use for a variety of purposes. The catalytic performance of VOPO4 has been evaluated in the synthesis of nitrogen-doped carbon dots (N-CDs). The synthesis reaction was carried out at 180 °C using VOPO4 as a heterogeneous catalyst for 2 to 4 h of reaction time. After reaction, the N-CDs were purified using a novel method for the protection of the functional groups over the surfaces of the N-CDs. The morphological, superficial, and photoelectronic properties of the N-CDs were thoroughly studied by means of TEM, HRTEM, XPS, and photoluminescence measurements. The conversion of the carbon precursor was followed by HPLC. After three catalytic runs, the catalyst was still active while ensuring the quality of the N-CDs obtained. After the third cycle, the catalyst was regenerated, and it recovered its full activity. The obtained N-CDs showed a great degree of oxidized groups in their surfaces that translated into high photoluminescence when irradiated under different lasers. Due to the observed photoelectronic properties, they were then assayed in the photocatalytic degradation of methyl orange.
Open Access
Prediction of protein targets in ovarian cancer using a ru-complex and carbon dot drug delivery therapeutic nanosystems: a bioinformatics and µ-FTIR spectroscopy approach
(MDPI, 2024) Nesic, Maja D.; Dučić, Tanja; Gemović, Branislava; Senćanski, Milan; Algarra González, Manuel; Gonçalves, Mara; Stepic, Milutin; Popovic, Iva; Kapuran, Đorđe; Petkovic, Marijana; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
We predicted the protein therapeutic targets specific to a Ru-based potential drug and its combination with pristine and N-doped carbon dot drug delivery systems, denoted as RuCN/CDs and RuCN/N-CDs. Synchrotron-based FTIR microspectroscopy (µFTIR) in addition to bioinformatics data on drug structures and protein sequences were applied to assess changes in the protein secondary structure of A2780 cancer cells. µFTIR revealed the moieties of the target proteins’ secondary structure changes only after the treatment with RuCN and RuCN/N-CDs. A higher content of α-helices and a lower content of β-sheets appeared in A2780 cells after RuCN treatment. Treatment with RuCN/N-CDs caused a substantial increase in parallel β-sheet numbers, random coil content, and tyrosine residue numbers. The results obtained suggest that the mitochondrion-related proteins NDUFA1 and NDUFB5 are affected by RuCN either via overexpression or stabilisation of helical structures. RuCN/N-CDs either induce overexpression of the β-sheet-rich protein NDUFS1 and affect its random coil structure or interact and stabilise its structure via hydrogen bonding between -NH2 groups from N-CDs with protein C=O groups and –OH groups of serine, threonine, and tyrosine residues. The N-CD nanocarrier tunes this drug’s action by directing it toward a specific protein target, changing this drug’s coordination ability and inducing changes in the protein’s secondary structures and function.
Open Access
Nitrogen doped carbon dots as a photocatalyst based on biomass: a life cycle assessment
(Elsevier, 2023) Rodríguez-Carballo, Gabriela; Moreno-Tost, Ramón; Fernandes, Sónia; Esteves da Silva, Joaquim C.G.; Pinto da Silva, Luís; Castro Galiano, Eulogio; Algarra González, Manuel; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
The effectiveness of various transition metal phosphate-based acid catalysts, including vanadium and niobium, in the hydrothermal synthesis of carbon dots (CDs), has been assessed. Two sources of carbohydrates were employed for this: commercial xylose and liquor of xylose produced by processing olive pits. Catalysts were identified using the NH3-TPD, DTA/TG, XRD, and XPS techniques. The reaction was conducted for 4 h at a temperature of 180 °C. The existence of such nanoparticles, regardless of the carbohydrate source, was confirmed by an analysis of the features and characteristics of CDs nanoparticles. N-doped CDs with increased fluorescence were also created at the same time using a similar hydrothermal technique, and their photocatalytic activity was investigated. A Life Cycle Assessment (LCA) was conducted for both syntheses with the goal of comparing the environmental effects of the synthesis from commercial xylose to the synthesis from biomass. It was revealed that, although energy is the primary driver of both synthesis pathways' effect categories, the fundamental variations that seem to determine their relative sustainability are connected to the nature of the carbon precursor. Regarding the latter, it is determined that electricity has the greatest environmental impact.
Open Access
Synergistic enhancement of targeted wound healing by near-infrared photodynamic therapy and silver metal-organic frameworks combined with S- or N-doped carbon dots
(MDPI, 2024) Nesic, Maja D.; Popovic, Iva; Zakula, Jelena; Koricanac, Lela; Filipovic Trickovic, Jelena; Valenta Šobot, Ana; Jiménez, María Victoria; Algarra González, Manuel; Dučić, Tanja; Stepic, Milutin; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
The literature data emphasize that nanoparticles might improve the beneficial effects of near-infrared light (NIR) on wound healing. This study investigates the mechanisms of the synergistic wound healing potential of NIR light and silver metal–organic frameworks combined with nitrogen- and sulfur-doped carbon dots (AgMOFsN-CDs and AgMOFsS-CDs, respectively), which was conducted by testing the fibroblasts viability, scratch assays, biochemical analysis, and synchrotron-based Fourier transform infrared (SR-FTIR) cell spectroscopy and imaging. Our findings reveal that the combined treatment of AgMOFsN-CDs and NIR light significantly increases cell viability to nearly 150% and promotes cell proliferation, with reduced interleukin-1 levels, suggesting an anti-inflammatory response. SR-FTIR spectroscopy shows this combined treatment results in unique protein alterations, including increased α-helix structures and reduced cross-β. Additionally, protein synthesis was enhanced upon the combined treatment. The likely mechanism behind the observed changes is the charge-specific interaction of N-CDs from the AgMOFsN-CDs with proteins, enhanced by NIR light due to the nanocomposite’s optical characteristics. Remarkably, the complete wound closure in the in vitro scratch assay was achieved exclusively with the combined NIR and AgMOFsN-CDs treatment, demonstrating the promising application of combined AgMOFsN-CDs with NIR light photodynamic therapy in regenerative nanomedicine and tissue engineering.
Open Access
Efficient and scalable gene delivery method with easily generated cationic carbon dots
(BMC, 2024) Algarra González, Manuel; González-Muñoz, Elena; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
Gene delivery is a complex process with several challenges when attempting to incorporate genetic material efficiently and safely into target cells. Some of the key challenges include not only efficient cellular uptake and endosomal escape to ensure that the genetic material can exert its effect but also minimizing the toxicity of the delivery system, which is vital for safe gene delivery. Of importance, if gene delivery systems are intended for biomedical applications or clinical use, they must be scalable and easy and affordable to manufacture to meet the demand. Here, we show an efficient gene delivery method using a combination of carbon dots coated by PEI through electrostatic binding to easily generate cationic carbon dots. We show a biofunctional approach to generate optimal cationic carbon dots (CCDs) that can be scaled up to meet specific transfection demands. CCDs improve cell viability and increase transfection efficiency four times over the standard of PEI polyplexes. Generated CCDs enabled the challenging transfection protocol to produce retroviral vectors via cell cotransfection of three different plasmids into packing cells, showing not only high efficiency but also functionality of the gene delivery, tested as the capacity to produce infective retroviral particles.
Open Access
Lipid status of A2780 ovarian cancer cells after treatment with ruthenium complex modified with carbon dot nanocarriers: a multimodal SR-FTIR spectroscopy and MALDI TOF Mass Spectrometry Study MALDI TOF Mass Spectrometry Study
(MDPI, 2022) Nesic, Maja D.; Dučić, Tanja; Algarra González, Manuel; Popovic, Iva; Stepic, Milutin; Gonçalves, Mara; Petkovic, Marijana; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
In the last decade, targeting membrane lipids in cancer cells has been a promising approach that deserves attention in the field of anticancer drug development. To get a comprehensive understanding of the effect of the drug [Ru(¿5-Cp)(PPh3)2CN] (RuCN) on cell lipidic components, we combine complementary analytical approaches, matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI TOF MS) and synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectroscopy. Techniques are used for screening the effect of potential metallodrug, RuCN, without and with drug carriers (carbon dots (CDs) and nitrogen-doped carbon dots (N-CDs)) on the lipids of the human ovarian cancer cell line A2780. MALDI TOF MS results revealed that the lysis of ovarian cancer membrane lipids is promoted by RuCN and not by drug carriers (CDs and N-CDs). Furthermore, SR-FTIR results strongly suggested that the phospholipids of cancer cells undergo oxidative stress after the treatment with RuCN that was accompanied by the disordering of the fatty acid chains. On the other hand, using (N-)CDs as RuCN nanocarriers prevented the oxidative stress caused by RuCN but did not prevent the disordering of the fatty acid chain packing. Finally, we demonstrated that RuCN and RuCN/(N-)CDs alter the hydration of the membrane surface in the membrane—water interface region.
Open Access
Visible-light-driven photocatalytic degradation of organic dyes using a TiO2 and waste-based carbon dots nanocomposite
(Elsevier, 2025-05-20) Sendão, Ricardo M.S.; Algarra González, Manuel; Lázaro-Martínez, Juan; Brandão, Ana T.S.C.; Gil Bravo, Antonio; Pereira, Carlos; Esteves da Silva, Joaquim C.G.; Pinto da Silva, Luís; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
Herein we report a visible-light-active photocatalytic nanocomposite (NC50:50) prepared from carbon dots (CDs) and TiO2 nanoparticles, which was applied to the photodegradation of organic dyes in water. The CDs incorporated corn stover, a major agricultural waste, and were prepared via hydrothermal treatment. Using a visible-light irradiation source and the dye methylene blue as a representative of the organic dyes class, we observed that a 374% enhancement of the catalytic performance was achieved by adding CDs relative to bare TiO2. This was possible due to increased visible-light absorption and better photonic efficiency. Tests using reactive species scavengers indicated that three active species (superoxide anion, hydroxyl radicals, and electrons) were responsible for the photodegradation process, differing from bare TiO2 in which only the hydroxyl radical has a relevant role. Photocatalytic degradation was also observed toward Rhodamine B, Orange II and Methyl Orange. Finally, we performed a life cycle assessment (LCA) study to assess and analyse the associated environmental impacts of NC50:50 compared with other alternatives, which revealed that NC50:50 is the alternative resulting in the least environmental impacts. In summary, NC50:50 could, under visible-light irradiation, efficiently remove different organic dyes while incorporating organic waste materials and reducing the impacts associated with their use. We expect that this study provides a base for a more environmentally sustainable design of visible-light-active photocatalysts via waste upcycling.
Open Access
A sustainable approach for the valorization of lignocellulosic biomass in active photo- and electrocatalyst carbon dots
(Springer, 2024) Jorge, Herculys Bernardo; Gier Della-Rocca, Daniela; Herrera, Elisa Gabriela; Rodríguez-Castellón, Enrique; Gil Bravo, Antonio; Amorim, Suélen Maria de; Winiarski, Joao Paulo; Vieira, Iolanda da Cruz; Peralta Muniz Moreira, Regina de Fatima; Algarra González, Manuel; Peralta, Roselyn Aparecida; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
The recovery or degradation of organic wastes in the circular economy concept continues to be environmental protection challenges. In this study, we proposed a metal catalyst free production of useful non-doped (CDs) and nitrogen doped carbon dots (N-CDs) nanoparticles, generated from a greener hydrothermal top-down method, using paper scraps solid organic wastes from the pulp and paper industry. Both materials were fully characterized. At the same time, these high-added value materials were used as catalysts for the photocatalytic degradation of pollutants and for generating hydrogen through hydrogen evolution reaction (HER). The morphological study revealed the presence of nanoparticles with a higher carbon content than the raw biomass, from 13 to 51 wt% as assessed by X-ray photoelectron spectroscopy (XPS), ranging in size from 4.4 to 6.8 nm. The ability of these materials to catalyze the photodegradation of 4-nitrophenol has been tentatively investigated. The N-CDs proved to be more active than undoped-CDs to degrade 4-nitrophenol due to the smaller bandgap and more active sites available which will also accept the transferred electrons for H2 generation or 4-nitrophenol reduction.