BUSCADOR RECOLECTA

The relevance of the asymmetric Biginelli reaction (ABR) has been increased in this century, due to the pharmacological application of its products. This review focuses predominantly on articles published in the period from 2015 to 2024 on asymmetric synthetic advances in the formation of dihydropyrimidinones (DHPMs), dihydropyrimidinethiones (DHPMTs), and related compounds. The relevant bibliography on general processes in the Biginelli reaction and some methods of separation of isomers have also been referenced., Financial support has been received from the Spanish Ministry of Science and Innovation RTI2018-098296-BI00 (MINECO and FEDER), and M. Algarra would like to thank the Ministry of Science and Innovation (MCIN/AEI/https://doi.org/10.13039/501100011033) for their support under the grant number PID2021-122613OB-I00

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., From Ministerio de Ciencia e Innovación del Gobierno de España (grant number
PID2021-124033OB-I00), from Consejería Economía y Conocimiento Junta de
Andalucía-FEDER (grant number UMA18-FEDERJA-107) and from Ministry of
Science and Innovation (MCIN/AEI/https://doi.org/10.13039/501100011033)
for financial support (grant number PID2021-122613OB-I00).

Heterogeneous bi-magnetic nanostructured systems have had a sustained interest during the last decades owing to their unique magnetic properties and the wide range of derived potential applications. However, elucidating the details of their magnetic properties can be rather complex. Here, a comprehensive study of Fe3O4/Mn3O4 core/shell nanoparticles using polarized neutron powder diffraction, which allows disentangling the magnetic contributions of each of the components, is presented. The results show that while at low fields the Fe3O4 and Mn3O4 magnetic moments averaged over the unit cell are antiferromagnetically coupled, at high fields, they orient parallel to each other. This magnetic reorientation of the Mn3O4 shell moments is associated with a gradual evolution with the applied field of the local magnetic susceptibility from anisotropic to isotropic. Additionally, the magnetic coherence length of the Fe3O4 cores shows some unusual field dependence due to the competition between the antiferromagnetic interface interaction and the Zeeman energies. The results demonstrate the great potential of the quantitative analysis of polarized neutron powder diffraction for the study of complex multiphase magnetic materials., I.V.G. acknowledges financial support from the Russian Foundation for Basic Research under Grant No 20-02-00109. A.G.R. and J.N. acknowledge financial support from the grants PID2019-106229RB-I0 funded by MCIN/AEI/10.13039/50110001103 and 2021-SGR-00651 from Generalitat de Catalunya. I.K. and A.G. acknowledge the European Union's H2020 reserach and innovation program, Grant agreement No 871072. A.G.R. acknowledges financial support from RYC2019-027449-I funded by MCIN/AEI/10.13039/501100011033. ICN2 is funded by the CERCA programme/Generalitat de Catalunya. The ICN2 is supported by the CEX2021–001214–S grant funded by MCIN/AEI/10.13039/501100011033. M.E. acknowledges the grants RYC2018-024396-I and PID2019-106165GB-C22 funded by MCIN/AEI/ 10.13039/501100011033 and by “ESF Investing in your future.” A.L.O. acknowledges financial support from the grants PID2021-122613OB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and PJUPNA2020 from Universidad Pública de Navarra.

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., The authors thank the Ministry of Science, Technological Development, and Innovation
of the Republic of Serbia (451-03-66/2024-03/200017) and the Spanish Ministry of Science and
Innovation (MCIN/AEI/10.13039/501100011033) through the project PID2021-122613OB-I00.

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., This research was funded by the Spanish Ministry of Science and
Innovation (PID2021- 122736OB-C42), FEDER (European Union) funds
(PID2021-122736OB-C42, P20-00375, UMA20- FEDERJA88). M.A
thanks to the Spanish Ministry of Science and Innovation (MCIN/AEI/
10.13039/501100011033) through project PID2021-122613OB-I00.
This work was made in the framework of projects UIDB/00081/2020
(CIQUP), UIDB/05748/2020 (GreenUPorto), LA/P/00081/2020 (IMS),
and PTDC/QUI-QFI/2870/2020, funded by the Portuguese Foundation
for Science and Technology (FCT, Lisbon). Luís Pinto da Silva acknowledges
funding from FCT under the Scientific Employment Stimulus
(CEECINST/00069/2021), while S.F acknowledges FCT for funding
of her Ph.D. grant (2021. 05479.BD).

This work analyzes chemical surface and optical characteristics of a commercial nanoporous
alumina structure (NPAS) as a result of surface coverage by different imidazolium-based ionic liquids
(1-butyl-3-metylimidazolium hexafluorophosphate, 3-methyl-1-octylimidazolium hexafluorophosphate, or 1-ethyl-3-methylimidazolium tetrafluoroborate). Optical characteristics of the IL/NPAS
samples were determined by photoluminescence (at different excitation wavelengths (from 300 nm
to 400 nm), ellipsometry spectroscopy, and light transmittance/reflectance measurements for a range
of wavelengths that provide information on modifications related to both visible and near-infrared
regions. Chemical surface characterization of the three IL/NPAS samples was performed by X-ray
photoelectron spectroscopy (XPS), which indicates almost total support coverage by the ILs. The
IL/NPAS analyzed samples exhibit different photoluminescence behavior, high transparency (<85%),
and a reflection maximum at wavelength ~380 nm, with slight differences depending on the IL, while
the refractive index values are rather similar to those shown by the ILs. Moreover, the illuminated
I–V curves (under standard conditions) of the IL/NPAS samples were also measured for determining
the efficiency energy conversion to estimate their possible application as solar cells. On the other
hand, a computational quantum mechanical modeling method (DFT) was used to establish the most
stable bond between the ILs and the NPAS support., M.A. thanks the SpanishMinistry of Science and Innovation (MCIN/AEI/10.13039/
501100011033) through project PID2021-122613OB-I00.

Nanoparticle-based nanocarriers represent a viable alternative to conventional direct administration in cancer cells. This advanced approach employs the use of nanotechnology to transport therapeutic agents directly to cancer cells, thereby reducing the risk of damage to healthy cells and enhancing the efficacy of treatment. By approving nanoparticle-based nanocarriers, the potential for targeted, effective treatment is greatly increased. The so-called carbon-based nanoparticles, or carbon dots, have been hydrothermally prepared and initiated by a polymerization process. We synthesized and characterized nanoparticles of 2-acrylamido-2-methylpropanesulfonic acid, which showed biocompatibility with glioblastoma cells, and further, we tested them as a carrier for the drug riluzole. The obtained nanoparticles have been extensively characterized by techniques to obtain the exact composition of their surface by using Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance (NMR) spectroscopy, as well as cryo-transmission electron microscopy. We found that the surface of the synthesized nanoparticles (NPs) is covered mainly by sulfonated, carboxylic, and substituted amide groups. These functional groups make them suitable as carriers for drug delivery in cancer cells. Specifically, we have successfully utilized the NPs as a delivery system for the drug riluzole, which has shown efficacy in treating glioblastoma cancer cells. The effect of nanoparticles as carriers for the riluzole system on glioblastoma cells was studied using live-cell synchrotron-based FTIR microspectroscopy to monitor in situ biochemical changes. After applying nanoparticles as nanocarriers, we have observed changes in all biomacromolecules, including the nucleic acids and protein conformation. These findings provide a strong foundation for further exploration into the development of targeted treatments for glioblastoma., The authors are grateful for financial support from the Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033) through project PID2021-122613OB-I00 as well as the ALBA In-house grant: “Synergetic multimodal FTIR and X-ray spectro-microscopical approach for 3D cell culture evaluation”. Open access funding is provided by Universidad Pública de Navarra. The authors acknowledge funding from Project, IU16-014045 (CRYO-TEM) from Generalitat de Catalunya and by “ERDF A way of making Europe”, by the European Union.

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., This research was funded by the Spanish Ministry of Science and Innovation (PID2021-122736OB-C42, PID2021-122613OB-I00) and FEDER (European Union) funds (PID2021-122736OB-C42, P20-00375, UMA20-FEDERJA88).

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., Authors thank to Spanish Ministry of Science and Innovation (MCIN/
AEI/10.13039/501100011033) though the projects PID2021-
122613OB-I00 and PID2021-126235OB-C32 and P18-RT-4592 of Junta
de Andalucía and FEDER funds, and the Ministry of Science, Technological Development, and Innovation of the Republic of Serbia (grant
451-03-47/2023-01/200017).

Additive manufacturing technology has attracted the attention of industrial and technological sectors due to the versatility
of the design and the easy manufacture of structural and functional elements based on composite materials. The embedding
of magnetic nanoparticles in the polymeric matrix enables the development of an easy manufacturing process of low-cost
magnetically active novel polymeric composites. In this work, we report a series of magnetic composites prepared by solution
casting method combining 5 to 60 wt.% of 140 ± 50 nm commercial Fe3O4
nanoparticles, with a semi-crystalline, biocompatible,
and biodegradable polymeric blend made of polylactic acid (PLA) and polycaprolactone (PCL). The composites were
extruded, obtaining 1.5 ± 0.2 mm diameter continuous and flexible filaments for fused deposition modelling 3D printing.
The chemical, magnetic, and calorimetric properties of the obtained filaments were investigated by differential scanning
calorimetry, thermogravimetric analysis, magnetometry, and scanning electron microscopy. Furthermore, taking advantage
of the magnetic character of the filaments, their capability to generate heat under the application of low-frequency alternating
magnetic fields (magnetic induction heating) was analyzed. The obtained results expose the versatility of these easy
manufacturing and low-cost filaments, where selecting a desired composition, the heating capacity can be properly adjusted
for those applications where magnetic induction plays a key role (i.e., magnetic hyperthermia, drug release, heterogeneous
catalysis, water electrolysis, gas capture, or materials synthesis)., Open Access funding provided by Universidad Pública de Navarra. This work has been carried out with the financial support of the Navarra Government (project number PC017-018 AMELEC). The Spanish Government is acknowledged for the HIPERNANO research network (RED2018-102626-T). ALO acknowledges financial support from the grants PID2021-122613OB-I00 funded by MCIN/AEI/10.13039/501100011033 and PJUPNA2020 from Universidad Pública de Navarra. P. La Roca has received funding from “la Caixa” and “Caja Navarra” Foundations, under agreement LCF/PR/PR13/51080004.

In this work, we have studied the photodissociation of the protonated derivatives of N-nitrosodimethylamine [(CH3)2N–NO] with the
CASPT2 method. It is found that only one of the four possible protonated species of the dialkylnitrosamine compound absorbs in the visible region at 453 nm, that is, N-nitrosoammonium ion [(CH3)2NH-NO]+
. This species is also the only one whose first singlet excited state
is dissociative to directly yield the aminium radical cation [(CH3)2NHN⋅]
+
and nitric oxide. In addition, we have studied the intramolecular proton migration reaction {[(CH3)2N–NOH]
+ → [(CH3)2NH–NO]+
} both in the ground and excited state (ESIPT/GSIPT); our results
indicate that this process is not accessible neither in the ground nor in the first excited state. Furthermore, as a first approximation,
MP2/HF calculations on the nitrosamine–acid complex indicate that in acidic solutions of aprotic solvents, only [(CH3)2NH–NO]+
is
formed., This work was supported by the Spanish Ministry of Science
and Innovation (Grant No. MCIN/AEI/10.13039/501100011033)
through Project No. PID2021-122613OB-I00.

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., The research was funded by the Ministry of Science, Technological Development and Innovation of the Republic of Serbia (451-03-66/2024-03/200017). The authors are grateful for financial support from the Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033) through project PID2021-122613OB-I00, and also to FCT (CQM Base Fund—UIDB/00674/2020, Programmatic Fund—UIDP/00674/2020); Madeira 14-20 Program (project Reforço do Investimentoem Equipamentos e Infrastructures Científcasna RAM (PROEQUIPRAM) M1420-01-0145-FEDER-000008); and Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI) through the ARDITI-CQM/2018/007-PDG (Fellowship Grant to M.G.), project M1420-01-0145-FEDER-000005-CQM+ (Madeira 14–20).

Heterogeneous bi-magnetic nanostructured systems have had a sustained interest during the last decades owing to their unique magnetic properties and the wide range of derived potential applications. However, elucidating the details of their magnetic properties can be rather complex. Here, a comprehensive study of Fe3 O4 /Mn3 O4 core/shell nanoparticles using polarized neutron powder diffraction, which allows disentangling the magnetic contributions of each of the components, is presented. The results show that while at low fields the Fe3 O4 and Mn3 O4 magnetic moments averaged over the unit cell are antiferromagnetically coupled, at high fields, they orient parallel to each other. This magnetic reorientation of the Mn3 O4 shell moments is associated with a gradual evolution with the applied field of the local magnetic susceptibility from anisotropic to isotropic. Additionally, the magnetic coherence length of the Fe3 O4 cores shows some unusual field dependence due to the competition between the antiferromagnetic interface interaction and the Zeeman energies. The results demonstrate the great potential of the quantitative analysis of polarized neutron powder diffraction for the study of complex multiphase magnetic materials., I.V.G. acknowledges financial support from the Russian Foundation for Basic Research under Grant No 20-02-00109. A.G.R. and J.N. acknowledge financial support from the grants PID2019-106229RB-I0 funded by MCIN/AEI/10.13039/50110001103 and 2021-SGR-00651 from Generalitat de Catalunya. I.K. and A.G. acknowledge the European Union's H2020 reserach and innovation program, Grant agreement No 871072. A.G.R. acknowledges financial support from RYC2019-027449-I funded by MCIN/AEI/10.13039/501100011033. ICN2 is funded by the CERCA programme/Generalitat de Catalunya. The ICN2 is supported by the CEX2021–001214–S grant funded by MCIN/AEI/10.13039/501100011033. M.E. acknowledges the grants RYC2018-024396-I and PID2019-106165GB-C22 funded by MCIN/AEI/ 10.13039/501100011033 and by “ESF Investing in your future.” A.L.O. acknowledges financial support from the grants PID2021-122613OB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and PJUPNA2020 from Universidad Pública de Navarra., With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001214-S)., Peer reviewed

Heterogeneous bi-magnetic nanostructured systems have had a sustained interest during the last decades owing to their unique magnetic properties and the wide range of derived potential applications. However, elucidating the details of their magnetic properties can be rather complex. Here, a comprehensive study of FeO/MnO core/shell nanoparticles using polarized neutron powder diffraction, which allows disentangling the magnetic contributions of each of the components, is presented. The results show that while at low fields the FeO and MnO magnetic moments averaged over the unit cell are antiferromagnetically coupled, at high fields, they orient parallel to each other. This magnetic reorientation of the MnO shell moments is associated with a gradual evolution with the applied field of the local magnetic susceptibility from anisotropic to isotropic. Additionally, the magnetic coherence length of the FeO cores shows some unusual field dependence due to the competition between the antiferromagnetic interface interaction and the Zeeman energies. The results demonstrate the great potential of the quantitative analysis of polarized neutron powder diffraction for the study of complex multiphase magnetic materials.