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- Gold nanoparticles deposited on surface modified carbon xerogels as reusable catalysts for cyclohexane C-H activation in the presence of CO and waterPublication . Ribeiro, Ana Paula da Costa; Martins, Luisa; Carabineiro, Sonia Alexandra Correia; Figueiredo, José; Pombeiro, ArmandoThe use of gold as a promotor of alkane hydrocarboxylation is reported for the first time. Cyclohexane hydrocarboxylation to cyclohexanecarboxylic acid (up to 55% yield) with CO, water, and peroxodisulfate in a water/acetonitrile medium at circa 50 °C has been achieved in the presence of gold nanoparticles deposited by a colloidal method on a carbon xerogel in its original form (CX), after oxidation with HNO3 (-ox), or after oxidation with HNO3 and subsequent treatment with NaOH (-ox-Na). Au/CX-ox-Na behaves as re-usable catalyst maintaining its initial activity and selectivity for at least seven consecutive cycles. Green metric values of atom economy or carbon efficiency also attest to the improvement brought by this novel catalytic system to the hydrocarboxylation of cyclohexane. View Full-Text
- Multifunctional gold-nanoparticles: A nanovectorization tool for the targeted delivery of novel chemotherapeutic agentesPublication . Fernandes, Alexandra; Jesus, João; Martins, Pedro; Figueiredo, Sara; Rosa, Daniela; Martins, Luisa; Corvo, M. Luísa; Carvalheiro, Manuela; Costa, Pedro M.; Baptista, PedroDue to their small size and unique properties, multifunctional nanoparticles arise as versatile delivery systems easily grafted with a vast array of functional moieties, such as anticancer cytotoxic chemotherapeutics and targeting agents. Here, we formulated a multifunctional gold-nanoparticle (AuNP) system composed of a monoclonal antibody against epidermal growth factor receptor (EGFR) (anti-EGFR D-11) for active targeting and a Co(II) coordination compound [CoCl(H2O)(phendione)2][BF4] (phendione = 1,10-phenanthroline-5,6-dione) (TS265) with proven antiproliferative activity towards cancer cells (designated as TargetNanoTS265). The efficacy of this nanoformulation, and the non-targeted counterpart (NanoTS265), were evaluated in vitro using cancer cell models and in vivo using mice xenografts. Compared to the free compound, both nanoformulations (TargetNanoTS265 and NanoTS265) efficiently delivered the cytotoxic cargo in a controlled selective manner due to the active targeting, boosting tumor cytotoxicity. Treatment of HCT116-derived xenografts tumors with TargetNanoTS265 led to 93% tumor reduction. This simple conceptual nanoformulation demonstrates the potential of nanovectorization of chemotherapeutics via simple assembly onto AuNPs of BSA/HAS-drug conjugates that may easily be expanded to suit other cargo of novel compounds that require optimized controlled delivery to cancer target.
- Gold nanoparticles deposited on surface modified carbon materials as reusable catalysts for hydrocarboxylation of cyclohexanePublication . Ribeiro, A. P. C.; Martins, Luisa; Carabineiro, S. A. C.; Figueiredo, J. L.Gold nanoparticles were deposited on different carbon materials and used as catalysts for the alkane hydrocarboxylation reaction. Cyclohexane hydrocarboxylation to cyclohexanecarboxylic acid was carried out in the presence of CO and water, peroxodisulfate, in water/acetonitrile medium, at ca. 50 degrees C, with gold nanoparticles deposited by a colloidal method on carbon nanotubes and activated carbon with three different surface chemistries: in their original forms (CNT or AC, respectively), oxidized with HNO3 (ox) or oxidized with HNO3 and subsequently treated with NaOH (-ox-Na). Au/CNT-ox-Na was the best catalyst, yielding cyclohexanecarboxylic acid up to 88.2% yield, with excellent recyclability (97.5% of the initial activity was maintained after five consecutive catalytic cycles).