Hybrid metal-phenol nanoparticles with polydopamine-like coating for PET/SPECT/CT imaging

Altres ajuts: the ICN2 is funded by the CERCA programme/Generalitat de Catalunya. The authors acknowledge the support from the Cost ENBA CA15216.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

Roadmap on nanomedicine for the central nervous system

In recent years, a great deal of effort has been undertaken with regards to treatment of pathologies at the level of the central nervous system (CNS). Here, the presence of the blood-brain barrier acts as an obstacle to the delivery of potentially effective drugs and makes accessibility to, and treatment of, the CNS one of the most significant challenges in medicine. In this Roadmap article, we present the status of the timeliest developments in the field, and identify the outstanding challenges and opportunities that exist. The format of the Roadmap, whereby experts in each discipline share their viewpoint and present their vision, reflects the dynamic and multidisciplinary nature of this research area, and is intended to generate dialogue and collaboration across traditional subject areas. It is stressed here that this article is not intended to act as a comprehensive review article, but rather an up-to-date and forward-looking summary of research methodologies pertaining to the treatment of pathologies at the level of the CNS

Organometallic Ruthenium Nanoparticles as Model Catalysts for CO Hydrogenation: A Nuclear Magnetic Resonance and Ambient-Pressure X-ray Photoelectron Spectroscopy Study

International audienceWe present a study of the structure and reactivity of Ru nanoparticles of different sizes (1.3, 1.9, and 3.1 nm) for CO hydrogenation using gas-phase nuclear magnetic resonance and mass spectroscopy. In addition, the nanoparticles were characterized under reaction mixtures in situ by ambient-pressure X-ray photoelectron spectroscopy. We found that during reaction the Ru is in the metallic state and that the diphosphine ligands [bis(diphenylphosphino)butane (dppb)] on the surface of 1.9 and 3.1 nm nanoparticles not only act as capping and protecting agents but also stay on the surface during reaction and improve their activity and selectivity toward C 2 −C 4 hydrocarbons

Organometallic Ruthenium Nanoparticles and Catalysis

International audienceDue to a high number of possible applications in various domains, metal nanoparticles are nowadays the subject of an extensive development. This interest in metal nanoparticles is related to their electronic properties at the frontier between those of molecular species and bulk compounds which are induced by their nanometric size. Regarding the field of catalysis, the growing attention for metal nanoparticles also results from the high proportion of surface atoms present in the upper layer of the metallic core which gives rise to numerous potential active sites. Thus, nanocatalysis (which involves the use of catalysts with at least one dimension at the nanoscale) has emerged in the field of modern catalysis as a domain on the borderline between homogeneous and heterogeneous catalysis. Present developments aim at multifunctionality which can be achieved by the proper design of complex nanostructures also named nanohybrids. In nanohybrid the term “hybrid” refers to the appropriate association between a metal core and a stabilizing shell such as a polymer, a ligand, an ionic liquid, or even a support (inorganic materials, carbon black, carbon nanotubes, etc.…). This association can be considered as crucial to tune the surface properties of nanostructures and consequently their catalytic performance. The main expectation for the scientific community is that precisely designed nanoparticles (in terms of size, shape, and composition including surface ligands) should offer the benefits of both homogeneous and heterogeneous catalysts, namely high efficiency and better selectivity