Amphiphilic COSAN and I2-COSAN crossing synthetic lipid membranes: planar bilayers and liposomes

The boron-rich cobaltabisdicarbollide (COSAN) and its 8,80-I2 derivative (I2-COSAN), both of purely inorganic nature, are shown to cross through synthetic lipid membranes. These results reveal unexpected properties at the interface of biological and synthetic membranes

New PtII diimine–dithiolate complexes containing a 1,2-dithiolate-1,2-closo-dicarbadodecarborane: an experimental and theoretical investigation

A new class of solvatochromic diimine–dithiolate complexes [Pt(N^N)(dtoc)] (dtoc2− = 1,2-dithiolate-1,2-closo-dicarbadodecaborane) is reported

Ion Transport across Biological Membranes by Carborane-Capped Gold Nanoparticles

Carborane-capped gold nanoparticles (Au/carborane NPs, 2-3 nm) can act as artificial ion transporters across biological membranes. The particles themselves are large hydrophobic anions that have the ability to disperse in aqueous media and to partition over both sides of a phospholipid bilayer membrane. Their presence therefore causes a membrane potential that is determined by the relative concentrations of particles on each side of the membrane according to the Nernst equation. The particles tend to adsorb to both sides of the membrane and can flip across if changes in membrane potential require their repartitioning. Such changes can be made either with a potentiostat in an electrochemical cell or by competition with another partitioning ion, for example, potassium in the presence of its specific transporter valinomycin. Carborane-capped gold nanoparticles have a ligand shell full of voids, which stem from the packing of near spherical ligands on a near spherical metal core. These voids are normally filled with sodium or potassium ions, and the charge is overcompensated by excess electrons in the metal core. The anionic particles are therefore able to take up and release a certain payload of cations and to adjust their net charge accordingly. It is demonstrated by potential-dependent fluorescence spectroscopy that polarized phospholipid membranes of vesicles can be depolarized by ion transport mediated by the particles. It is also shown that the particles act as alkali-ion-specific transporters across free-standing membranes under potentiostatic control. Magnesium ions are not transported

Boron clusters (ferrabisdicarbollides) shaping the future as radiosensitizers for multimodal (chemo/radio/PBFR) therapy of glioblastoma

Glioblastoma multiforme (GBM) is the most common and fatal primary brain tumor, and is highly resistant to conventional radiotherapy and chemotherapy. Therefore, the development of multidrug resistance and tumor recurrence are frequent. Given the poor survival with the current treatments, new therapeutic strategies are urgently needed. Radiotherapy (RT) is a common cancer treatment modality for GBM. However, there is still a need to improve RT efficiency, while reducing the severe side effects. Radiosensitizers can enhance the killing effect on tumor cells with less side effects on healthy tissues. Herein, we present our pioneering study on the highly stable and amphiphilic metallacarboranes, ferrabis(dicarbollides) ([o-FESAN]- and [8,8'-I2-o-FESAN]-), as potential radiosensitizers for GBM radiotherapy. We propose radiation methodologies that utilize secondary radiation emissions from iodine and iron, using ferrabis(dicarbollides) as iodine/iron donors, aiming to achieve a greater therapeutic effect than that of a conventional radiotherapy. As a proof-of-concept, we show that using 2D and 3D models of U87 cells, the cellular viability and survival were reduced using this treatment approach. We also tested for the first time the proton boron fusion reaction (PBFR) with ferrabis(dicarbollides), taking advantage of their high boron (11B) content. The results from the cellular damage response obtained suggest that proton boron fusion radiation therapy, when combined with boron-rich compounds, is a promising modality to fight against resistant tumors. Although these results are encouraging, more developments are needed to further explore ferrabis(dicarbollides) as radiosensitizers towards a positive impact on the therapeutic strategies for GBM.The authors received support from the Spanish Ministerio de Economía y Competitividad (PID2019-106832RB-100), the Generalitat de Catalunya (2017SGR1720), FCT - Fundação para a Ciência e a Tecnologia, in the scope of the project UID/Multi/04349/2019 and the projects LISBOA-01-0247-FEDER-045904 and UTAP-EXPL/FMT/0020/2021 of Centro de Ciências e Tecnologias Nucleares/IST, PTDC/BTM-TEC/29256/2017, UIDP/04565/2020 of iBB/IST, UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences – UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy – i4HB. The Metrology Laboratory of Ionizing Radiation team of Centro Tecnológico e Nuclear, Instituto Superior Técnico (CTN/IST) is acknowledged for their support in the irradiation setups. Miquel Nuez-Martínez is enrolled in the PhD program of the UAB. MQM and VMA acknowledge financial support by the Spanish Government MCIN/AEI/10.13039/501100011033 (project 2019-108434GB-I00 to VMA and project IJC2018-035283-I to MQM), and Universitat Jaume I (project UJI-B2018-53 to V. M. A. and project UJI-A2020-21 to MQM). SV thanks Croatian Science Foundation (project IP-2018-01-3168). Catarina I.G. Pinto is enrolled in the PhD scholarship 689 DFA/BD/07119/2020.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Preparation and characterization of au nanoparticles capped with mercaptocarboranyl clusters

The preparation of 3–4 nm and 10 nm gold nanoparticles capped with neutral carborane-based mercaptocarboranes, via two different preparative routes, is reported. The resulting boron-enriched nanomaterials exhibit complete dispersibility in water, opening the way for the use of these monolayer protected clusters (MPCs) in medical applications, such as boron neutron capture therapy (BNCT). These newly prepared MPCs have been characterized by FTIR, 1H and 11B NMR spectroscopy, UV-visible, centrifugal particle sizing (CPS), and, in some cases, inductively coupled plasma atomic emission spectrometry (ICP-AES). Water dispersibility exhibited by these MPCs allowed the study of the cellular uptake by HeLa cells

The first examples of η⁵-bonding of a carbaborylphosphine ligand to transition metals. Synthesis and characterisation of 7-{PPh₂AuPPh₃}-8-Ph-7,8-nido-C₂B ₉H₁₀, 1-{PPh₂AuCl}-2-Ph-3-(p-cymene)-3,1,2-pseudocloso-RuC ₂B₉H₉

The closo carbaborylmonophosphine 1-PPh2-2-Ph-1,2-closo-C2B10H10 is deboronated by reaction with ClAuPPh3 in refluxing ethanol to afford the zwitterionic compound 7-{PPh2AuPPh3}-8-Ph-7,8-nido-C2B 9H10, characterised by NMR spectroscopy and X-ray crystallography. Deprotonation of this species using NaH in THF followed by reaction with either [(p-cymene)RuCl2]2 or [(?-C5Me5)RhCl2]2 yields the compounds 1-{PPh2AuCl}-2-Ph-3-(p-cymene)-3,1,2-RuC2B 9H9 and 1-{PPh2AuCl}-2-Ph-3-(?-C5Me 5)-3,1,2-RhC2B9H9, respectively. These latter products, which on the basis of 11B-NMR spectroscopy and (in the first case) a single crystal diffraction analysis, have pseudocloso structures, are the first reported examples of compounds in which a carbaborylphosphine ligand is ?5-bonded to a transition metal.</p