Staff directory Salvio Suárez García

Salvio Suárez García

Senior Postdoctoral Researcher
Nanostructured Functional Materials



  • Antitumour activity of coordination polymer nanoparticles

    Suárez-García S., Solórzano R., Alibés R., Busqué F., Novio F., Ruiz-Molina D. Coordination Chemistry Reviews; 441 (213977) 2021. 10.1016/j.ccr.2021.213977. IF: 22.315

    Nanoscale coordination polymers (NCPs) have fascinated researchers over the last years. Their intrinsic theranostic properties of metal ions and organic ligands, the encapsulation of several drugs/biomolecules with excellent yields and the surface functionalisation, enhancing their biocompatibility and targeting, have remarkably impacted in prospective drug delivery alternatives in medicine. Moreover, the properties and characteristics of these nanoparticles (NPs) can be fine-tuned thanks to the synthetic flexibility of coordination chemistry. For all these reasons, the number of examples published has grown exponentially over the last years, embracing different disciplines such as molecular electronics, sensors or nanomedicine, among others. Specifically, significant advances in antitumoural applications are reported, one of the areas where this novel family of NPs has experienced a considerable advance. NCPs have accomplished a high sophistication degree and efficiency as theranostic nanoplatforms (i.e., drug delivery carriers and bioimaging probes) with long residence time in the bloodstream, targeting capacities and remarkable cellular internalisation. In this review, an introduction emphasizing the advantages of NPs for cancer treatment is included. Later on, the most representative examples of NCPs for antitumoural applications are described grouped into six mean representative areas: i) encapsulation approaches, ii) stimuli-responsive NCPs, iii) metal chemotherapy, iv) photodynamic therapy (PDT), v) unconventional therapeutic approaches and vi) theranostics. Particular emphasis is given to understand the encapsulation/release properties of these particles at the nanoscale and their interaction with biological environments, highlighting any limitation and challenges that these systems are facing from a clinical translation perspective and envisioning possible future trends and areas that will deserve further attention for the following years. © 2021 The Authors

  • Bioinspired theranostic coordination polymer nanoparticles for intranasal dopamine replacement in parkinson's disease

    García-Pardo J., Novio F., Nador F., Cavaliere I., Suárez-García S., Lope-Piedrafita S., Candiota A.P., Romero-Gimenez J., Rodríguez-Galván B., Bové J., Vila M., Lorenzo J., Ruiz-Molina D. ACS Nano; 15 (5): 8592 - 8609. 2021. 10.1021/acsnano.1c00453. IF: 15.881

    Dopamine (DA) is one of the main neurotransmitters found in the central nervous system and has a vital role in the function of dopaminergic (DArgic) neurons. A progressive loss of this specific subset of cells is one of the hallmarks of age-related neurodegenerative disorders such as Parkinson's disease (PD). Symptomatic therapy for PD has been centered in the precursor l-DOPA administration, an amino acid precursor of DA that crosses the blood-brain barrier (BBB) while DA does not, although this approach presents medium- to long-term side effects. To overcome this limitation, DA-nanoencapsulation therapies are actively being searched as an alternative for DA replacement. However, overcoming the low yield of encapsulation and/or poor biodistribution/bioavailability of DA is still a current challenge. Herein, we report the synthesis of a family of neuromelanin bioinspired polymeric nanoparticles. Our system is based on the encapsulation of DA within nanoparticles through its reversible coordination complexation to iron metal nodes polymerized with a bis-imidazol ligand. Our methodology, in addition to being simple and inexpensive, results in DA loading efficiencies of up to 60%. In vitro, DA nanoscale coordination polymers (DA-NCPs) exhibited lower toxicity, degradation kinetics, and enhanced uptake by BE(2)-M17 DArgic cells compared to free DA. Direct infusion of the particles in the ventricle of rats in vivo showed a rapid distribution within the brain of healthy rats, leading to an increase in striatal DA levels. More importantly, after 4 days of nasal administrations with DA-NCPs equivalent to 200 μg of the free drug per day, the number and duration of apomorphine-induced rotations was significantly lower from that in either vehicle or DA-treated rats performed for comparison purposes. Overall, this study demonstrates the advantages of using nanostructured DA for DA-replacement therapy. © 2021 American Chemical Society.

  • Coordination polymers nanoparticles for bioimaging

    Suárez-García S., Solórzano R., Novio F., Alibés R., Busqué F., Ruiz-Molina D. Coordination Chemistry Reviews; 432 (213716) 2021. 10.1016/j.ccr.2020.213716. IF: 22.315

    Early diagnosis of patient diseases is subjected to the appropriate use of bioimaging techniques. For this reason, the development of contrast agents that improve and enhance the response of current clinical imaging practices is a pressing concern. Non-invasive bioimaging techniques most often need specific probes to follow and measure biological routes in living systems. These molecular imaging agents must exhibit: I) a remarkable contrast effect, i.e. a high signal-to-noise ratio under real physiological conditions, II) pronounced in vivo stability under the effect of numerous enzymes or proteases present in serum or targeted tissue equilibrated with a fast clearance from healthy organs and III) low cost and eco-friendly production. To overcome current drawbacks that hindrance the full development of the different bioimaging techniques, several groups are exploring nanoparticles as contrast agents. In this scenario, coordination polymer nanoparticles have emerged as a handy platform offering predesigned unique advantages thanks to their chemical flexibility, structural diversity and tailoring skills. Indeed, these systems reveal high metal cargos, low toxicity and multifunctional character by adequately selecting the combination of metal ions and ligands. Moreover, in a reminiscent way of organic polymeric nanoparticles, coordination polymer nanoparticles have also demonstrated its ability to encapsulate therapeutic-active molecules, thus combining diagnostic and therapeutic functionalities, the so-called Theranostic nanomedicine. For all these reasons, the use of this family of nanoparticles as imaging contrast agents has attracted broad interest over the last years with numerous examples being reported. Herein, we review main accomplishments in the area grouped according to the used technology, including magnetic resonance imaging, computed tomography, optical imaging, radioimaging or photoacoustic imaging. © 2020 Elsevier B.V.

  • Gossypol treatment restores insufficient apoptotic function of dff40/cad in human glioblastoma cells

    Martínez-Escardó L., Alemany M., Sánchez-Osuna M., Sánchez-Chardi A., Roig-Martínez M., Suárez-García S., Ruiz-Molina D., Vidal N., Plans G., Majós C., Ribas J., Baltrons M.A., Bayascas J.R., Barcia C., Bruna J., Yuste V.J. Cancers; 13 (21, 5579) 2021. 10.3390/cancers13215579. IF: 6.639

    Glioblastoma (GBM) is a highly aggressive brain tumor and almost all patients die because of relapses. GBM-derived cells undergo cell death without nuclear fragmentation upon treatment with different apoptotic agents. Nuclear dismantling determines the point-of-no-return in the apoptotic process. DFF40/CAD is the main endonuclease implicated in apoptotic nuclear disassembly. To be properly activated, DFF40/CAD should reside in the cytosol. However, the endonuclease is poorly expressed in the cytosol and remains cumulated in the nucleus of GBM cells. Here, by employing commercial and non-commercial patient-derived GBM cells, we demonstrate that the natural terpenoid aldehyde gossypol prompts DFF40/CAD-dependent nuclear fragmentation. A comparative analysis between gossypol-and staurosporine-treated cells evidenced that levels of neither caspase activation nor DNA damage were correlated with the ability of each compound to induce nuclear fragmentation. Deconvoluted confocal images revealed that DFF40/CAD was almost completely excluded from the nucleus early after the staurosporine challenge. However, gossypol-treated cells maintained DFF40/CAD in the nucleus for longer times, shaping a ribbon-like structure piercing the nuclear fragments and building a network of bridged masses of compacted chromatin. Therefore, GBM cells can fragment their nuclei if treated with the adequate insult, making the cell death process irreversible. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

  • Hybrid Metal-Phenol Nanoparticles with Polydopamine-like Coating for PET/SPECT/CT Imaging

    SuÃirez-GarcÃ-A S., Esposito T.V.F., Neufeld-Peters J., Bergamo M., Yang H., Saatchi K., Schaffer P., HÃfeli U.O., Ruiz-Molina D., RodrÃ-Guez-RodrÃ-Guez C., Novio F. ACS Applied Materials and Interfaces; 13 (9): 10705 - 10718. 2021. 10.1021/acsami.0c20612. IF: 9.229

    The validation of metal-phenolic nanoparticles (MPNs) in preclinical imaging studies represents a growing field of interest due to their versatility in forming predesigned structures with unique properties. Before MPNs can be used in medicine, their pharmacokinetics must be optimized so that accumulation in nontargeted organs is prevented and toxicity is minimized. Here, we report the fabrication of MPNs made of a coordination polymer core that combines In(III), Cu(II), and a mixture of the imidazole 1,4-bis(imidazole-1-ylmethyl)-benzene and the catechol 3,4-dihydroxycinnamic acid ligands. Furthermore, a phenolic-based coating was used as an anchoring platform to attach poly(ethylene glycol) (PEG). The resulting MPNs, with effective hydrodynamic diameters of around 120 nm, could be further derivatized with surface-embedded molecules, such as folic acid, to facilitate in vivo targeting and multifunctionality. The prepared MPNs were evaluated for in vitro plasma stability, cytotoxicity, and cell internalization and found to be biocompatible under physiological conditions. First, biomedical evaluations were then performed by intrinsically incorporating trace amounts of the radioactive metals 111In or 64Cu during the MPN synthesis directly into their polymeric matrix. The resulting particles, which had identical physicochemical properties to their nonradioactive counterparts, were used to perform in vivo single-photon emission computed tomography (SPECT) and positron emission tomography (PET) in tumor-bearing mice. The ability to incorporate multiple metals and radiometals into MPNs illustrates the diverse range of functional nanoparticles that can be prepared with this approach and broadens the scope of these nanoconstructs as multimodal preclinical imaging agents. ©

  • Solvent-tuned ultrasonic synthesis of 2D coordination polymer nanostructures and flakes

    Pepió B., Contreras-Pereda N., Suárez-García S., Hayati P., Benmansour S., Retailleau P., Morsali A., Ruiz-Molina D. Ultrasonics Sonochemistry; 72 (105425) 2021. 10.1016/j.ultsonch.2020.105425. IF: 7.491

    Herein, a new 2-dimensional coordination polymer based on copper (II), {Cu2(L)(DMF)2}n, where L stands for 1,2,4,5-benzenetetracarboxylate (complex 1) is synthesized. Interestingly, we demonstrate that both solvent and sonication are relevant in the top-down fabrication of nanostructures. Water molecules are intercalated in suspended crystals of complex 1 modifying not only the coordination sphere of Cu(II) ions but also the final chemical formula and crystalline structure obtaining {[Cu(L)(H2O)3]·H2O}n (complex 2). On the other hand, ultrasound is required to induce the nanostructuration. Remarkably, different morphologies are obtained using different solvents and interconversion from one morphology to another seems to occur upon solvent exchange. Both complexes 1 and 2, as well as the corresponding nanostructures, have been fully characterized by different means such as infrared spectroscopy, x-ray diffraction and microscopy. © 2020 The Authors


  • Pathway selection as a tool for crystal defect engineering: A case study with a functional coordination polymer

    Abrishamkar A., Suárez–García S., Sevim S., Sorrenti A., Pons R., Liu S.-X., Decurtins S., Aromí G., Aguilà D., Pané S., deMello A.J., Rotaru A., Ruiz–Molina D., Puigmartí-Luis J. Applied Materials Today; 20 (100632) 2020. 10.1016/j.apmt.2020.100632. IF: 8.352

    New synthetic routes capable of achieving defect engineering of functional crystals through well-controlled pathway selection will spark new breakthroughs and advances towards unprecedented and unique functional materials and devices. In nature, the interplay of chemical reactions with the diffusion of reagents in space and time is already used to favor such pathway selection and trigger the formation of materials with bespoke properties and functions, even when the material composition is preserved. Following this approach, herein we show that a controlled interplay of a coordination reaction with mass transport (i.e. the diffusion of reagents) is essential to favor the generation of charge imbalance defects (i.e. protonation defects) in a final crystal structure (thermodynamic product). We show that this synthetic pathway is achieved with the isolation of a kinetic product (i.e. a metastable state), which can be only accomplished when a controlled interplay of the reaction with mass transport is satisfied. Accounting for the relevance of controlling, tuning and understanding structure-properties correlations, we have studied the spin transition evolution of a well-defined spin-crossover complex as a model system. © 2020 Elsevier Ltd


  • Delamination of 2D coordination polymers: The role of solvent and ultrasound

    Contreras-Pereda N., Hayati P., Suárez-García S., Esrafili L., Retailleau P., Benmansour S., Novio F., Morsali A., Ruiz-Molina D. Ultrasonics Sonochemistry; 55: 186 - 195. 2019. 10.1016/j.ultsonch.2019.02.014. IF: 7.279

    Two novel cadmium-based 2D coordination polymers have been synthesized and characterized. Experimental results evidence that the best delamination processes occurs when weak interactions dominate the cohesion between layers and solvent molecules are occluded within the crystalline network. In this case, the delamination of the crystals occurs spontaneously in water. On top of that, and thanks to the high stability of the resulting (flake) colloidal dispersions, we have completed a detailed study of the sonication assisted delamination impact by: I) comparison of two different sonication approaches (bath vs. tip sonication) and II) optimization of final flake morphology and yield by controlling solvent and sonication time. Our results definitely pave the way for the fabrication and implementation of 2D coordination polymers using ultrasound. © 2019 Elsevier B.V.


  • Dual T1/ T2 Nanoscale Coordination Polymers as Novel Contrast Agents for MRI: A Preclinical Study for Brain Tumor

    Suárez-García S., Arias-Ramos N., Frias C., Candiota A.P., Arús C., Lorenzo J., Ruiz-Molina D., Novio F. ACS Applied Materials and Interfaces; 10 (45): 38819 - 38832. 2018. 10.1021/acsami.8b15594. IF: 8.097

    In the last years, extensive attention has been paid on designing and developing functional imaging contrast agents for providing accurate noninvasive evaluation of pathology in vivo. However, the issue of false-positives or ambiguous imaging and the lack of a robust strategy for simultaneous dual-mode imaging remain to be fully addressed. One effective strategy for improving it is to rationally design magnetic resonance imaging (MRI) contrast agents (CAs) with intrinsic T1/T2 dual-mode imaging features. In this work, the development and characterization of one-pot synthesized nanostructured coordination polymers (NCPs) which exhibit dual mode T1/T2 MRI contrast behavior is described. The resulting material comprises the combination of different paramagnetic ions (Fe3+, Gd3+, Mn2+) with selected organic ligands able to induce the polymerization process and nanostructure stabilization. Among them, the Fe-based NCPs showed the best features in terms of colloidal stability, low toxicity, and dual T1/T2 MRI contrast performance overcoming the main drawbacks of reported CAs. The dual-mode CA capability was evaluated by different means: in vitro phantoms, ex vivo and in vivo MRI, using a preclinical model of murine glioblastoma. Interestingly, the in vivo MRI of Fe-NCPs show T1 and T2 high contrast potential, allowing simultaneous recording of positive and negative contrast images in a very short period of time while being safer for the mouse. Moreover, the biodistribution assays reveals the persistence of the nanoparticles in the tumor and subsequent gradual clearance denoting their biodegradability. After a comparative study with commercial CAs, the results suggest these nanoplatforms as promising candidates for the development of dual-mode MRI CAs with clear advantages. © 2018 American Chemical Society.

  • Sonochemical synthesis of a novel nanoscale 1D lead(II) [Pb2(L)2(I)4]n coordination Polymer, survey of temperature, reaction time parameters

    Hayati P., Suárez-García S., Gutiérrez A., Molina D.R., Morsali A., Rezvani A.R. Ultrasonics Sonochemistry; 42: 320 - 326. 2018. 10.1016/j.ultsonch.2017.11.033. IF: 6.012

    One new lead(II) coordination supramolecular complex (CSC) (1D), [Pb2(L)2(I)4]n, L = C4H6N2 (1-methyl imidazole), has been synthesized under different experimental conditions. Micrometric crystals (bulk) or nano-sized materials have been obtained depending on using the branch tube method or sonochemical irradiation. All materials have been characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Single crystal X-ray analyses on complex 1 showed that Pb2+ ion is 4-coordinated. Topological analysis shows that the complex 1 is 2,3,5C2 net. Finally, the role of reaction time and temperature on the growth and final morphology of the structures obtained by sonochemical irradiation have been studied. © 2017 Elsevier B.V.

  • Sonochemical synthesis of two novel Pb(II) 2D metal coordination polymer complexes: New precursor for facile fabrication of lead(II) oxide/bromide micro-nanostructures

    Hayati P., Suárez-García S., Gutierrez A., Şahin E., Molina D.R., Morsali A., Rezvani A.R. Ultrasonics Sonochemistry; 42: 310 - 319. 2018. 10.1016/j.ultsonch.2017.11.037. IF: 6.012

    Two new lead(II) coordination polymer complexes (CSCs) (2D), [Pb2(L)2(Br)2]n·H2O (1), [Pb2(HL/)(L/)(H2O)2]n·H2O (2), where L = C6H5NO2 (2-pyridinecarboxylic acid) and L/ = C9H6O6 (1,3,5-tricarboxylic acid), have been synthesized under different experimental conditions. Micrometric crystals (bulk) or microsized materials have been obtained depending on using the branch tube method or sonochemical irradiation. All materials have been characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Single crystal X-ray analyses on complexes 1 and 2 shows that Pb2+ ions are 8-coordinated, 7 and 9-coordinated, respectively. Topological analysis shows that the compound 1 and 2 are 4,6L26 and bnn net, respectively. However, neither the shape nor the morphology is maintained, showing the role of sonochemistry to modulate both morphology and dimensions of the resulting crystalline material, independently of whether we have a 2D coordination polymer (CP). Finally, micro structuration of lead(II) bromide oxide and lead(II) oxide have been prepared by calcination of two different lead (II) CPs at 700 °C that were characterized by SEM and XRD. © 2017 Elsevier B.V.

  • Spin-Crossover in an Exfoliated 2D Coordination Polymer and Its Implementation in Thermochromic Films

    Salvio Suárez-García, Nayarassery N. Adarsh, Gábor Molnár, Azzedine Bousseksou, Yann Garcia, Marinela M. Dîrtu, Javier Saiz-Poseu, Roberto Robles, Pablo Ordejón, and Daniel Ruiz-Molina ACS Applied Nano Materials; 1 (6): 2662 - 2668. 2018. 10.1021/acsanm.8b00341 . IF: 0.000

    Development of novel 2D materials with singular and thrilling properties has aroused large interest due to the novel unexpected applications that can be derived from there. In this sense, coordination polymers (CPs) have appeared as matching candidates thanks to their rational chemical design and the added-value properties given by the presence of metal ions. This is the case of switchable spin-crossover systems that have been proposed as excellent candidates for data storage or sensing, among others. Here we report the delamination of crystals of the 2D spin-crossover (SCO) {[Fe(L1)2](ClO4)2}∝ (1) CP by liquid-phase exfoliation (LPE) in water. The application of this top-down technique results in the formation of flakes with controlled thicknesses, down to 1–2 nm thick (mostly mono- and bilayer), that retain the chemical composition and SCO interconversion of the bulk material. Moreover, these flakes can be handled as stable colloidal dispersions for many days. This allows for a controlled transfer to solid substrates and the formation of thermochromic polymeric films as a proof-of-concept of device. These first results will definitely open new venues and opportunities for the investigation and future integration of these original switchable 2D materials in devices.