Search results for "Functionalized"
showing 10 items of 47 documents
Functionalized halloysite nanotubes: Efficient carrier systems for antifungine drugs
2018
Abstract Halloysite-cyclodextrin hybrid was employed as carrier for sustained release of clotrimazole for vaginal or buccal treatment of Candidiasis. The nanocarrier was obtained by functionalization of halloysite surface with cyclodextrin moieties by means of microwave irradiation, with the final goal to obtain a scaffold for the covalent linkage of cysteamine hydrochloride. The interaction between clotrimazole and the pristine components, namely cyclodextrin and halloysite, was thoroughly investigated by several techniques such as DSC, TGA, UV–vis spectroscopy and some adsorption studies were, also, carried out. The release of the antifungine molecule was finally investigated in a medium …
Progress in Understanding of the Interactions between Functionalized Polyolefins and Organo-Layered Double Hydroxides
2014
The dispersion of organo-layered double hydroxides (O-LDH) in functionalized polyolefins (POs) is investigated. Two different polyethylene matrices (maleic anhydride (MAH) and diethyl maleate functionalized) are tested and a hydrogenated fatty acid modified LDH is used. The attention is focused on evidencing the interaction between the functional groups of the polymer and the O-LDH through FT-IR. Moreover, a combination of solvent fractionation, morphological, and rheological characterizations enables to gain a deeper insight into the structure of these composites. In particular, the formation of bridging bonds between the particles and MAH functionalized macromolecules is assumed, possibly…
Calcium binding and ionic conduction in single conical nanopores with polyacid chains: model and experiments.
2012
Calcium binding to fixed charge groups confined over nanoscale regions is relevant to ion equilibrium and transport in the ionic channels of the cell membranes and artificial nanopores. We present an experimental and theoretical description of the dissociation equilibrium and transport in a single conical nanopore functionalized with pH-sensitive carboxylic acid groups and phosphonic acid chains. Different phenomena are simultaneously present in this basic problem of physical and biophysical chemistry: (i) the divalent nature of the phosphonic acid groups fixed to the pore walls and the influence of the pH and calcium on the reversible dissociation equilibrium of these groups; (ii) the asym…
Insertion Reactions of Neutral Phosphidozirconocene Complexes as a Convenient Entry into Frustrated Lewis Pair Territory
2016
International audience; Neutral phosphidozirconocene complexes [Cp2Zr(PR2)Me] (Cp=cyclopentadienyl; 1a: R=cyclohexyl (Cy); 1b: R=mesityl (Mes); 1c: R=tBu) undergo insertion into the Zr-P bond by non-enolisable carbonyl building blocks (O=CRR), such as benzophenone, aldehydes, paraformaldehyde or CO2, to give [Cp2Zr(OCRRPR2)Me] (3-7). Depending on the steric bulk around P, complexes 3-7 react with B(C6F5)(3) to give O-bridged cationic zirconocene dimers that display typical frustrated Lewis pair (FLP)/ambiphilic ligand behaviour. Thus, the reaction of {[Cp2Zr(-OCHPhPCy2)][MeB(C6F5)(3)]}(2) (10a) with chalcone results in 1,4 addition of the Zr+/P FLP, whereas the reaction of {[Cp2Zr(-OCHFcPCy…
General route to dissymmetric heteroannular-functionalized ferrocenyl 1,2-diphosphines: selective synthesis and characterization of a new class of tr…
2006
Several monosubstituted-cyclopentadienyl anions (A-Li) and [1,2-bis(diphenylphosphino)-4-tert-butylcyclopentadienyl]lithium (B-Li) react with FeCl2 to afford a novel class of multidentate ferroceny...
Polyfunctional Tetraaza-Macrocyclic Ligands: Zn(II), Cu(II) Binding and Formation of Hybrid Materials with Multiwalled Carbon Nanotubes
2017
The binding properties of HL1, HL2, and HL3 ligands toward Cu(II) and Zn(II) ions, constituted by tetraaza-macrocyclic rings decorated with pyrimidine pendants, were investigated by means of potentiometric and UV spectrophotometric measurements in aqueous solution, with the objective of using the related HL-M(II) (HL = HL1–HL3; M = Cu, Zn) complexes for the preparation of hybrid MWCNT-HL-M(II) materials based on multiwalled carbon nanotubes (MWCNTs), through an environmentally friendly noncovalent procedure. As shown by the crystal structure of [Cu(HL1)](ClO4)2, metal coordination takes place in the macrocyclic ring, whereas the pyrimidine residue remains available for attachment onto the s…
New folate-functionalized biocompatible block copolymer micelles as potential anti-cancer drug delivery systems
2006
Abstract The main objective of this study was to synthesize novel folic acid-functionalized diblock copolymer micelles and evaluate their solubilization of two poorly water-soluble anti-tumor drugs, tamoxifen and paclitaxel, which suffer from low water solubility and/or poor hydrolytic stability. The diblock copolymer consisted of a permanently hydrophilic block comprising 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) residues and a pH-sensitive hydrophobic block comprising 2-(diisopropylamino)ethyl methacrylate (DPA) residues. Folic acid (FA) was conjugated to the end of the MPC block so that this group was located on the micelle periphery. Tamoxifen- and paclitaxel-loaded micelles were…
Pyrene-functionalized nanoparticles: two independent sensors, the excimer and the monomer.
2012
The high surface-to-volume ratio of nanoparticles has been used to obtain a high local concentration of pyrene units on their periphery, making the formation of both pyrene emissive species possible using amazingly small pyrene concentrations. The sensing properties of model pyrene-functionalized nanoparticles was investigated by using different nitroaromatic compounds [m-nitroaniline and p-nitroaniline] and nitrobenzenes [nitrobenzene, p-nitrotoluene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene]. The hybrid system acts as a dual-fluorescence sensor, in which the decrease of the pyrene emission, induced by the quencher, is hardly reflected in the pyrene excimer emission. The encapsulation ca…
In vivo biodistribution of amino-functionalized ceria nanoparticles in rats using positron emission tomography.
2012
A variety of nanoparticles have been proposed for several biomedical applications. To gauge the therapeutic potential of these nanoparticles, in vivo biodistribution is essential and mandatory. In the present study, ceria nanoparticles (5 nm average particle size) were labeled with F-18 to study their in vivo biodistribution in rats by positron emission tomography (PET). The F-18 isotope was anchored by reaction of N-succinimidyl 4-[F-18]fluorobenzoate (F-18-SFB) with a modified nanoparticle surface obtained by silylation with 3-aminopropylsilyl. Radiolabeled ceria nanoparticles accumulated mainly in lungs, spleen, and liver. Metabolic products of the radiolabeled nanoparticulate material w…
Radiation engineered nanogels as platforms for medical diagnostics and therapeutic nanodevices
2015
A scalable, single step, synthetic approach for the manufacture of biocompatible, functionalized microgels and nanogels has been developed. Pulsed EB irradiation of PVP aqueous solutions, at relatively low energies per pulse and doses within the sterilization dose range, has led to a variety of ‘as-born’ sterile, functional nanostructures that exhibit a combination of favourable properties which make them suitable as biomedical nanocarriers. Reactive functional groups have been generated by graft copolymerization of functional acrylic monomers. These groups can be used to attach fluorescent probes to the NPs, to bioconjugate ligands of specific cell receptors and to incorporate therapeutics…