Research Topics

The research activities in the Bonifazi group are centred on ambitious targeted organic synthesis, carbon-based nanostructure chemistry, self-assembly and self-organisation studies to develop practical access to functional organic architectures displaying tailored properties for real world-technologies. Current research interests can be divided in four main topics:

Since its creation at the end of 2006, our team has been very active in the field of supramolecular organic chemistry at interfaces, with the objective of taking advantage of the supramolecular approach as a route to build defined two- and three-dimensional nano-patterned organic networks. We have validated the concept for which complementary H-bonding interactions can serve as powerful and versatile tool for tuning the shape of materials giving access to an enormous number of structurally-organized architectures, mastering their organization from the nanoscale up to the macroscopic level [Chem. Eur. J., 2009, 15, 7004; Coord. Chem. Rev., 2010, 254, 2342; Pure Appl. Chem., 2010, 10, 917; Nanoscale, 2013, 5, 8837]. In a collaborative research program with the group of Prof. M. Stohr (University of Groningen, Holland), exploiting the triply H-bonded uracil-2,6-diamidopyridine recognition motif linked to oligo(phenylene-ethynylene) molecular wires, we have reported the first example, at that time, of a simultaneous three-components H-bonded assembly on Ag(111) surfaces by STM analysis under ultrahigh vacuum conditions (UHV). [Angew. Chem. Int. Ed., 2008, 47, 7726]

Simultaneously, for the first time, we also reported the first writable organic-based surfaces based on thermally switchable 2D porous assembly [Chem. Commun., 2009, 3525]. Discrete assemblies, featuring hosting properties towards hydrophobic porphyrin guests, have been also formed using complementary angular modules. The multicomponent non-covalent H-bonded hollowed assemblies featuring polygonal porous domains (in coll. with Prof. P Samori at Universisty of Strasbourg, France) have also been comprehensively investigated at the solid-liquid interfaces, for the first time showing that both the network and the phase depend on the molecular geometry, concentrations and the peculiar chemical structure [Chem. Commun., 2008, 5289; Adv. Funct. Mater., 2009, 19, 1207; J. Am. Chem. Soc., 2009, 131, 509; J. Am. Chem. Soc., 2009, 131, 13062]. Passing from the molecular to the nanoscale, our team has also shown how the use of H-bonding allowed the tuning of the size and shape of uniform architectures enabling a morphological change to occur from nanoparticle and vesicles [Chem. Commun., 2009, 2830]. The formation of helicoidally organized rods, crater-, prism- and crown-like morphologies have been also fully described [Chem. Eur. J., 2010, 17, 3262; Langmuir, 2011, 27, 1513].

Aiming at introducing asymmetric properties and relate molecular and macroscopic chirality [ChemPlusChem, 2014, 79, 895], we have very recently engineered a new family of BINOLs derivatives undergoing solvent-dependent nanostructuration. Depending on the solvophobic properties of the liquid media, the material can be moulded into spherical, rod-like, fibrous and helical morphologies [J. Am. Chem. Soc., 2015, 137, 8150]. This behaviour is interpreted as a consequence of an interplay between the degree of association of the H-bond recognition, the vapour pressure of the solvent and the solvophobic/solvophilic character of the supramolecular adducts in the different solutions under dynamic conditions, namely during solvent evaporation conditions at room temperature.

In collaboration with the group of Prof. J. Barth and Prof. W. Auwarter (TUM), we have described for the first time the formation of discrete, tunable and hollowed cyclic supramolecular architectures on insulating boron-nitrate [J. Am. Chem. Soc., 2015, 137, 2420] and on metal surfaces exploiting metal-coordination bonding interactions with pyridyl-bearing ligands [Nano Lett., 2010, 10, 122; J. Am. Chem. Soc., 2010, 132, 6783; ACS Nano, 2010, 6, 4936], the structure of which could be tailored by the geometry, conformational flexibility and functionality of the porphyrin molecular modules. Recently, we have also reported the first patterning of lanthanide and transition metal atoms on surfaces exploiting the orthogonal coordination properties of tetrapyridyl porphyrins [Angew. Chem. Int. Ed., 2015, 54, 6163]. Expanding the topic, a series of differently substituted pyridyl-bearing pyrenyl modules [ACS Nano, 2016, 10, 7665] have been prepared, all showing a different self-assembly behavior (e.g., spangling, crocheting and knitting) depending on the spatial disposition of the pyridyl groups. Extended porous networks showing inherent flexibility and adaptability properties have been prepared exploiting competing non-covalent interactions, using tripodal modules like 1,3,4-tris-pyridyl-benzene [ACS Nano, 2012, 6, 4258; Chem. Eur. J., 2013, 14143]. In a parallel study, in collaboration with the groups of Prof. G. Costantini (Warwick University, United Kingdom) and Prof. A. De Vita (King’s College, United Kingdom), we demonstrated that polyaromatic hydrocarbons form nanostructures at the interface that are ruled by an interplay between van der Waals attractions and intermolecular repulsions, the latter driven by reversible molecule-substrate charge transfer [ACS Nano, 2014, 8, 12356, Nanoscale, 2016, 8, 19004].

Aiming at introducing a certain functionality on porous self-assembled organic networks, we have very recently initiated a novel research project (sponsored by the ERC Starting Grant 2012, COLORLANDS) in which, taking advantage of the molecular self-assembly, we seek to create a new generation of periodically-organized organic architectures that can structurally control the arrangement of molecular chromophores and/or fluorophores. The ultimate aim is to create a library of supramolecularly-assembled architectures emitting or adsorbing light throughout the visible region that, depending on their spatial organization, are suitable for producing versatile organic materials for device implementation (e.g. an OLED with luminophores or an artificial “leafs” mimicking natural antenna if hosting chromophores). In this respect, we conceived a facile and versatile protocol for the simultaneous use of three orthogonal dynamic covalent reactions, namely disulfide, boronate and acyl hydrazine formation. Using a pre-programmed a-helix peptide, we conceived a facile and versatile protocol to spatially organize tailored blue, red and yellow chromophores [Angew. Chem. Int. Ed., 2015, 54, 15739].

The inorganic mimic of benzene, borazine, first reported by Stock in 1926 possesses a wide energy gap of ~6 eV, although displaying similarity to benzene in both geometry and in formal topology of the π-molecular orbitals. The UV emissive properties of borazine and of its potential oligomeric derivatives make such molecular substrates attractive candidates to be implemented as active layer in UV light-emitting devices (LEDs) where high photon energy is necessary for either processing or sensing/characterization purposes. Thus, we turned our attention to borazine units as substituting unit to replace aromatic six-member rings [Chem. Commun., 2015, 51, 5222]. However, the susceptibility of the BN bonds to undergo hydrolysis in the presence of moisture is one of the major deterrent toward the use of this substrate, and attempts to significantly prevent the hydrolytic decomposition of borazines by introduction of various substituents were not successful until bulky substituents were placed in the ortho positions of B-aryl groups [Chem. Eur. J., 2013, 19, 7771].

With this approach, different borazine derivatives could be prepared, laterally exposing different functional groups. The electroluminescent properties of borazine-containing LEDs and LECs devices (in coll. with Prof. F. Cacialli, UCL London, United Kingdom) showed for the first time an UV-electroluminescent behavior. One patents also cover these works [WO 2012/126842]. Exploiting the decarbonilative [4+2] cycloaddition route, we have very recently tackled the first synthesis of borazine-based dendritic structures. Upon increasing the number of the borazine cores, a dramatic enhancement the UV-centered emission quantum yield has been observed, up to 60% for the heptaborazino-doped derivative [J. Am. Chem. Soc., 2017, 139, 503]. Also, we have prepared hydroxyl- and methyl-pentaaryl borazine molecules and studied their self-assembly behavior on a metal surface to prepare unprecedented bottom-up borazine-based supramolecular architectures [Angew. Chem. Int. Ed., 2013, 52, 7410; Chem. Eur. J., 2014, 20, 11856].

By means of the STM technique (Prof. G. Costantini, University of Warwick, United Kingdom and Prof. A. De Vita King’s College, United Kingdom) it has been found that hydroxyl-pentaaryl borazine molecules assemble in magic clusters of 7, 10, 11, 12, and 13 monomers on Cu(111). When peripheral ethynyl-phenyl substituents are added, porous networks are obtained with the borazine essentially decoupled from the metal surface (Cu or Au) [Chem. Eur. J., 2014, 20, 11856].Angew. Chem. Int. Ed., 2016, 55, 5947]. This allowed us to develop the first family of O-doped dyes, the type of O-annulation revealed to dictate the HOMO-LUMO gap and its chromatic properties.

Descending in the chalcogenic group, we also tackled the synthesis of Se- and Te-doped scaffolding, in particular the benzo-1,3-chalcogenazoles. Exceptionally, these aromatic heterocycles proved to be very stable and thus very handy to form controlled solid-state organizations in which wire-like polymeric structures are formed through secondary N…Y bonding interactions engaging the chalcogen (Y = Se or Te) and nitrogen atoms. In particular, it has been shown that the recognition properties of the chalcogen center at the solid state could be programmed by selectively barring one of its σ-holes through a combination of electronic and steric effects exerted by the substituent at the 2-position.

As predicted by the electrostatic potential surfaces calculated by quantum chemical modeling, the pyridyl groups revealed to be the stronger chalcogen bonding acceptors, and thus the best ligand candidate for programming the molecular organization at the solid state. The weaker chalcogen donor properties of the Se-analogues trigger the formation of feeble N…Se contacts, which are manifested in similar solid-state polymers featuring longer nitrogen-chalcogen distances [Chem. Eur. J., 2015, 21, 15377].

Cellular motility is nowadays well recognised as a key process involved in both physiological and pathological phenomena. In the immune system, an elaborate network of signalling directs leukocytes from the circulation into the surrounding tissue to destroy invading microorganisms and infected cells. In vertebrate adults, cell motility is a critical part of wound healing and tissue repair and it is also critical in disease states where the failure of migratory processes results in chronic inflammatory, vascular diseases, multiple sclerosis, and even mental retardation. Furthermore, aberrant cell migration in tumour invasion and metastasis is one the leading causes for cancer. Aiming at interfacing supramolecular chemistry with cell migration to govern its directionality, we very decided to explore this field, as it could lead to new paradigms to study new approaches for control cell growth, tumour invasion, and tissue regeneration. Physical and chemical cues such as the concentration gradients of signalling molecules are the main guiding stimuli for cell migration, inducing cell polarity and thus controlling the migration rate and direction.

Exploiting the haptotactic cellular response and taking advantage of the SAMs approach, we have engineered motogenic surfaces in which different cells displayed different migratory reactions. Contrary to the majority of the reports in which SAMs of Arginine-Glycine-Aspartic (RGD) peptides are used to induce migratory events as a consequence of a change of the surface adhesive properties, we have used for the first time the isoleucine-glycine-aspartic (IGD) peptidic motif present in the fibronectin gelating-binding domain. By preparing mixed SAMs on Au(111) exposing a chemical gradient of IGD-containing synthetic peptide, we could prepare for the first time motogenic surfaces displaying a truly macroscopic unidirectional migratory event of the deposited cells [Small, 2016, 12, 321]. By preparing mixed SAMs on Au(111) exposing a chemical gradient of IGD-containing synthetic peptide, we could prepare for the first time motogenic surfaces displaying a truly macroscopic unidirectional migratory event of the deposited cells. In particular, comparing the migratory response of human dermal fibroblasts (isolated from fetal skin, AG04431 skin HDFs) and cancer cells (MDA-MB-231, a model of human breast cancer), a different spatio-temporal migratory response could be observed for the two cellular typologies. Propelled by these achievements, we are now expanding our studies toward more complex systems in which bidirectional (or even multidirectional) cellular movements can be remotely controlled through external stimuli. Once achieved, future perspectives in this field will tackle the supramolecular modulation and control of the interactions between cells, aiming at triggering their interconnectivity and thus intercellular communications, essential actions for ruling a collective migratory behavior. In this respect, genetically-modified models cells are currently being investigated to interface specific receptor sites with artificial recognition units that are responsive toward an external stimulus.

Focusing on the CNTs-driven activities, our team has developed the first route based on H-bond driven reversible exohedral solubilization/functionalization of multi-walled MWCNTs in apolar organic solvents [J. Am. Chem. Soc., 2011, 133, 15412]. It has been demonstrated that efficient dispersion of CNTs could be obtained through a dynamic combination of self-assembly and self-organization processes involving first the formation of a supramolecular polymer, and subsequently its intertwinement around the outer wall of the MWCNTs (multiwalled carbon nanotubes).

Aiming at extending the concept to aqueous solutions for probing biochemical properties, we have also engineered supramolecular polymers efficiently dispersing CNTs in water and in biological media, in which the lateral alkyl substituents have been replaced by PEG-type chains. This is extremely useful to further increase the water solubility of our recently designed biocompatible, magnetically-active, Fe-filled CNTs [Adv. Funct. Mater., 2013, 23, 3173; Chem. Eur. J., 2015, 21, 9288; Nanoscale, 2015, 7, 20474].

Through a covalent linkage, we recently prepared exohedrally-functionalized Fe-filled CNTs with monoclonal antibody Cetuximab (in coll. with Prof. C. Michiels, University of Namur, Belgium), known to selectively bind the epidermal growth factor receptor (EGFR), a plasma membrane receptor over-expressed (EGFR+) in several cancer cells. In-vitro magnetic filtration experiments demonstrated that a selective removal of cancer cells (red: cancer cells, green: healthy cells) from a mixed population could be obtained with the hybrid material. Aiming at understanding the nature of the interactions between the tubular framework and the antibody, molecular dynamic and docking simulations of the Cetuximab-CNT bioconjugates were performed displaying the predominant role of the hydrophobic interactions [Chem. Eur. J., 2013, 19, 12281; Chem. Soc. Rev., 2015, 44, 6916]. Experiments to determine the bio-distribution profile of the CNT hybrids through magnetic resonance imaging (MRI) both in-vivo and after organ dissection are on going.

In another direction, following our seminal collaborative report with the group led by Prof. N. Armaroli (ISOF-CNR, Bologna, Italy) on luminescent CNTs [Adv. Funct. Mater., 2007, 17, 2975] in which we figured out that the low-lying electronic levels of CNTs do not quench lanthanide-centered emission, we have developed a series of protocols [Chem. Commun., 2011, 47, 1626; invited paper] for the covalent and non-covalent functionalization of MWCNTs with Eu(III) complexes. In order to further enhance the complex loading, MWCNTs were covalently functionalized with a second-generation positively-charged polycationic polyamidoamine (PAMAM) dendron presenting four ammonium groups per grafted aryl moiety [Chem. Eur. J., 2012, 18, 5889]. These newly-designed emissive CNTs hybrids are now being tested as active layers in electroluminescent devices (OLEDs, LECs) where the presence of the carbon material could provide substantial improvements of the conduction properties. In a parallel venue, we also developed an encapsulation protocol to prepare endohedral luminescent MWCNTs with a neutral and hydrophobic tris-hexafluoro acetylacetonate Eu(III) complex [Chem. Eur. J., 2011, 17, 8533]. Another encapsulated material, in which a fullerene-based carrier directed the encapsulation of a negatively-charged Eu(III) complex, has been also prepared showing an enhanced luminescent output suitable for bio-imaging applications [Nanoscale, 2014, 6, 2887].

Aiming at organizing carbon nanotubes in molecular materials, we have designed the first example of anisotropic fluorescent, thermoresponsive hydrogels containing Eu(III)-CNT hybrids, in which a water-soluble polycationic polyvinylpyridinium polymer is ion-paired with an anionic Eu(III) complex [Adv. Mater., 2013, 25, 2462]. Upon alignment of the CNT frameworks induced via a magnetic field, the emission properties of the hydrogel resulted anisotropically affected as compared to the non-magnetically treated materials. Based on these results, future directions with CNTs in our research group are focused on the design and engineering of hierarchically-structured CNTs-based materials in which organic or inorganic molecular guests are encapsulated inside the tubular hollow cavity [New J. Chem., 2014, 38, 22], exploiting in-situ and ex-situ protocols, and the external surface is exohedrally modified with covalent or non-covalent peripheral groups. While the electronic active features are dictated by the cavity-induced self-organized guest molecules, the final applications (i.e., catalysis, electrochromic or emitting devices) influence the choice of the external functionalization [Chem. Eur. J., 2015, 36, 12769]. Parts of the research objectives described in this section are supported by the European ‘SACS’ project (NMP-FP7 framework). Two main materials are targeted: a) CNT templates shaping hierarchical photosynthetic systems and b) functional platforms for magnetic-driven applications [Chem. Eur. J., 2015, 21, 9288].

Related Publications
Boron Nitride-Doped Polyphenylenic Organogels

Boron Nitride-Doped Polyphenylenic Organogels

J. Dosso, H. Oubaha, F. Fasano, S. Melinte, J.-F. Gohy, C.E. Hughes, K.D.M. Harris, N. Demitri, M. Abrami, M. Grassi, D. Bonifazi
Chemistry of Materials 34 (23)
18 Nov 2021

Herein, we describe the synthesis of the first boron nitride-doped polyphenylenic material obtained through a [4 + 2] cycloaddition reaction between a triethynyl borazine unit and a biscyclopentadienone derivative, which undergoes organogel formation in chlorinated solvents (the critical jellification concentration is 4% w/w in CHCl3). The polymer has been characterized extensively by Fourier-transform infrared spectroscopy, solid-state 13C NMR, solid-state 11B NMR, and by comparison with the isolated monomeric unit. Furthermore, the polymer gels formed in chlorinated solvents have been thoroughly characterized and studied, showing rheological properties comparable to those of polyacrylamide gels with a low crosslinker percentage. Given the thermal and chemical stability, the material was studied as a potential support for solid-state electrolytes. showing properties comparable to those of polyethylene glycol-based electrolytes, thus presenting great potential for the application of this new class of material in lithium-ion batteries.

Engineering Te-Containing Recognition Modules for ChalcogenBonding: Towards Supramolecular Polymeric Materials

Engineering Te-Containing Recognition Modules for ChalcogenBonding: Towards Supramolecular Polymeric Materials

D. Romito, D. Bonifazi.
Helvetica Chimica Acta 106 (2)
5 Dec 2023

Aiming at the preparation of one-dimensional (1D) chalcogen-bonded supramolecular polymers at the solid state, this work describes the different syntheses which have been challenged to obtain ditopic molecular modules. At first, tellurazolopyridyl (TZP) rings have been chosen as recognition units, given their well-proven ability and persistency to self-assemble through double Te⋅⋅⋅N chalcogen bonds (ChBs). The second synthetic strategy dealt with the preparation of pyridyl-modified ebselen Te-containing analogues. By attempting several synthetic protocols, the targeted ebselen derivatives could not be obtained, whereas an unexpected Te-containing lactone as well as a spiro-type Te(IV)-containing derivatives were isolated, with the latter investigated by X-ray diffraction (XRD) analysis.

Expanding the Library of 2-Phenylbenzotellurazoles: Red-Shifting Effect of Ethoxy Functionalities on the UV/Vis Absorption Properties

Expanding the Library of 2-Phenylbenzotellurazoles: Red-Shifting Effect of Ethoxy Functionalities on the UV/Vis Absorption Properties

Deborah Romito, Leonardo Amendolare, Krishnan K Kalathil, Davide Bonifazi
Synthesis 55(02)
10 May 2022

This work describes the high-yield synthesis of a novel series of benzotellurazoles bearing a phenyl ring in 2-position, which is differently functionalized with ethoxy chains. Changing the number and the position of these functional groups determines differences in the self-assembly in the solid state, as well as in the photophysical properties of the targeted molecules. As anticipated by theoretical calculations of the HOMO-LUMO gap of each molecule, the presence of ethoxy chains in o– and p-positions determines up to 20 nm red-shifts in the absorption peaks, when compared to unsubstituted benzotellurazole. Similarly, more significant changes are observed in the chemical shifts of 125Te NMR spectra for those derivatives bearing o– and p-ethoxy functionalization.

Photoreduction of Anthracenes Catalyzed by peri-Xanthenoxanthene: a Scalable and Sustainable Birch-Type Alternative

Photoreduction of Anthracenes Catalyzed by peri-Xanthenoxanthene: a Scalable and Sustainable Birch-Type Alternative

Cristian De Luca, Davide Zanetti, Dr. Tommaso Battisti, Rúben R. Ferreira, Sofia Lopez, Dr. Alexander H. McMillan, Dr. Sasha Cai Lesher-Pérez, Dr. Laura Maggini, Prof. Dr. Davide Bonifazi
Chemistry A European Journal 63
18 Aug 2023

The typical Birch reduction transforms arenes into cyclohexa-1,4-dienes by using alkali metals, an alcohol as a proton source, and an amine as solvent. Capitalizing on the strong photoreductive properties of peri-xanthenoxanthene (PXX), herein we report the photocatalyzed “Birch-type” reduction of acenes by employing visible blue light irradiation at room temperature in the presence of air. Upon excitation at 405 or 460 nm in the presence of a mixture of N,N-diisopropylethylamine (DIPEA) and trifluoromethanesulfonimide (HNTf2) in DMSO, PXX photocatalyzes the selective reduction of full-carbon acene derivatives (24–75 %). Immobilization of PXX onto polydimethylsiloxane (PDMS) beads (PXX-PDMS) allowed the use of the catalyst in heterogeneous batch reactions, giving 9-phenyl-9,10-dihydroanthracene in high yield (68 %). The catalyst could easily be recovered and reused, with no notable drop in performance observed after five reaction cycles. Integration of the PXX-PDMS beads into a microreactor enabled the reduction of acenes under continuous-flow conditions, thereby validating the sustainability and scalability of this heterogeneous-phase approach.

Photoredox Annulation of Polycyclic Aromatic Hydrocarbons

Photoredox Annulation of Polycyclic Aromatic Hydrocarbons

Davide Zanetti, Oliwia Matuszewska, Giuliana Giorgianni, Cristofer Pezzetta, Nicola Demitri, and Davide Bonifazi
14 Nov 2023

The rise of interest in using polycyclic aromatic hydrocarbons (PAHs) and molecular graphenoids in optoelectronics has recently stimulated the growth of modern synthetic methodologies giving access to intramolecular aryl–aryl couplings. Here, we show that a radical-based annulation protocol allows expansion of the planarization approaches to prepare functionalized molecular graphenoids. The enabler of this reaction is peri-xanthenoxanthene, the photocatalyst which undergoes photoinduced single electron transfer with an ortho-oligoarylenyl precursor bearing electron-withdrawing and nucleofuge groups. Dissociative electron transfer enables the formation of persistent aryl radical intermediates, the latter undergoing intramolecular C–C bond formation, allowing the planarization reaction to occur. The reaction conditions are mild and compatible with various electron-withdrawing and -donating substituents on the aryl rings as well as heterocycles and PAHs. The method could be applied to induce double annulation reactions, allowing the synthesis of π-extended scaffolds with different edge peripheries.

Tweaking the Optoelectronic Properties of S-Doped Polycyclic Aromatic Hydrocarbons by Chemical Oxidation

Tweaking the Optoelectronic Properties of S-Doped Polycyclic Aromatic Hydrocarbons by Chemical Oxidation

Matuszewska, O., Battisti, T., Ferreira, R.R., Biot, N., Demitri, N., Mézière, C., Allain, M., Sallé, M., Mañas-Valero, S., Coronado, E., Fresta, E., Costa, R..D. and Bonifazi, D.
Chemistry–A European Journal 29
4 Nov 2022

Peri-thiaxanthenothiaxanthene, an S-doped analog of peri-xanthenoxanthene, is used as a polycyclic aromatic hydrocarbon (PAH) scaffold to tune the molecular semiconductor properties by editing the oxidation state of the S-atoms. Chemical oxidation of peri-thiaxanthenothiaxanthene with H2O2 led to the relevant sulfoxide and sulfone congeners, whereas electrooxidation gave access to sulfonium-type derivatives forming crystalline mixed valence (MV) complexes. These complexes depicted peculiar molecular and solid-state arrangements with face-to-face p-p stacking organization. Photophysical studies showed a widening of the optical bandgap upon progressive oxidation of the S-atoms, with the bis-sulfone derivative displaying the largest value (E00 = 2.99 eV). While peri-thiaxanthenothiaxanthene showed reversible oxidation properties, the sulfoxide and sulfone derivatives mainly showed reductive events, corroborating their n-type properties. Electric measurements of single crystals of the MV complexes exhibited a semiconducting behavior with a remarkably high conductivity at room temperature (10-1-10-2 S cm-1 and 10-2-10-3 S cm-1 for the O and S derivatives, respectively), one of the highest reported so far. Finally, the electroluminescence properties of the complexes were tested in light-emitting electrochemical cells (LECs), obtaining the first mid-emitting PAH-based LECs.

peri-Acenoacene Ribbons with Zigzag BN-Doped Peripheries

peri-Acenoacene Ribbons with Zigzag BN-Doped Peripheries

Franceschini, M., Crosta, M., Ferreira, R. R., Poletto, D., Demitri, N., Zobel, J. P., González, L., and Bonifazi, D.
Journal of the American Chemical Society 144 (47)
17 Nov 2022

Here, we report the synthesis of BN-doped graphenoid nanoribbons, in which peripheral carbon atoms at the zigzag edges have been selectively replaced by boron and nitrogen atoms as BN and NBN motifs. This includes high-yielding ring closure key steps that, through N-directed borylation reaction using solely BBr3, allow the planarization of meta-oligoarylenyl precursors, through the formation of B–N and B–C bonds, to give ter-, quater-, quinque-, and sexi-arylenyl nanoribbons. X-ray single-crystal diffraction studies confirmed the formation of the BN and NBN motifs and the zigzag-edged topology of the regularly doped ribbons. Steady-state absorption and emission investigations at room temperature showed a systematic bathochromic shift of the UV–vis absorption and emission envelopes upon elongation of the oligoarylenyl backbone, with the nanoribbon emission featuring a TADF component. All derivatives displayed phosphorescence at 77 K. Electrochemical studies showed that the π-extension of the peri-acenoacene framework provokes a lowering of the first oxidative event (from 0.83 to 0.40 V), making these nanoribbons optimal candidates to engineer p-type organic semiconductors.

Indacaterol inhibits collective cell migration and IGDQ-mediated single cell migration in metastatic breast cancer MDA-MB-231 cells

Indacaterol inhibits collective cell migration and IGDQ-mediated single cell migration in metastatic breast cancer MDA-MB-231 cells

Sophie Ayama-Canden, Rodolfo Tondo, Martha Liliana Pineros Leyton, Noëlle Ninane, Catherine Demazy, Marc Dieu, Antoine Fattaccioli, Aude Sauvage, Tijani Tabarrant, Stéphane Lucas, Davide Bonifazi & Carine Michiels
Cell Communication and Signaling 21
30 Oct 2023
IGDQ motogenic peptide gradient induces directional cell migration through integrin (αv)β3 activation in MDA-MB-231 metastatic breast cancer cells

IGDQ motogenic peptide gradient induces directional cell migration through integrin (αv)β3 activation in MDA-MB-231 metastatic breast cancer cells

S. Ayama-Canden, R. Tondo, L. Piñeros, N. Ninane, C. Demazy, M. Dieu, A. Fattaccioli, T. Tabarrant, S. Lucas, D. Bonifazi, C. Michiels
Neoplasia 31
1 Sep 2022

In the context of breast cancer metastasis study, we have shown in an in vitro model of cell migration that IGDQ-exposing (IsoLeu-Gly-Asp-Glutamine type I Fibronectin motif) monolayers (SAMs) on gold sustain the adhesion of breast cancer MDA-MB-231 cells by triggering Focal Adhesion Kinase and integrin activation. Such tunable scaffolds are used to mimic the tumor extracellular environment, inducing and controlling cell migration. The observed migratory behavior induced by the IGDQ-bearing peptide gradient along the surface allows to separate cell subpopulations with a “stationary” or “migratory” phenotype. In this work, we knocked down the integrins α5(β1) and (αv)β since they are already known to be implicated in cell migration. To this aim, a whole proteomic analysis was performed in beta 3 integrin (ITGB3) or alpha 5 integrin (ITGA5) knock-down MDA-MB-231 cells, in order to highlight the pathways implied in the integrin-dependent cell migration.

Our results showed that i) ITGB3 depletion influenced ITGA5 mRNA expression, ii) ITGB3 and ITGA5 were both necessary for IGDQ-mediated directional single cell migration and iii) integrin (αv)β3 was activated by IGDQ fibronectin type I motif. Finally, the proteomic analysis suggested that co-regulation of recycling transport of ITGB3 by ITGA5 is potentially necessary for directional IGDQ-mediated cell migration.