Search results for "FARMACEUTICO"
showing 10 items of 419 documents
Synthesis and in vitro studies on a potential dopamine prodrug.
2008
Dopamine delivery to the central nervous system (CNS) undergoes the permeability limitations of blood-brain barrier (BBB) which is a selective interface that excludes most water-soluble molecules from entering the brain. Neutral amino acids permeate the BBB by specific transport systems. Conden- sation of dopamine with neutral amino acids could afford potential prodrugs able to interact with the BBB endogenous transporters and easily enter the brain. The synthesis and characterization of the dopamine derivative 2-amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide (7) is de- scribed. The chemical and enzymatic stability of 7 was evaluated. The molecular weight (300 Da) and Log P …
Inulin-iron complexes: a potential treatment of iron deficiency anaemia.
2007
The aim of this work was that to synthesize macromolecular derivatives based on inulin able to complex iron and useful in the treatment of iron deficiency anaemia. Carboxylated or thiolated/carboxylated inulin derivatives were obtained by single or double step reactions, respectively. The first one was obtained by reaction of inulin (INU) with succinic anhydride (SA) alone obtaining INU-SA derivative; the second one was obtained by the reaction of INU with succinic anhydride and subsequent reaction of INU-SA with cysteine; both derivatives were treated with ferric chloride in order to obtain the INU-SA-Fe(III) and INU-SA-Cys-Fe(III) complexes. Both complexes showed an excellent biodegradabi…
NEW SELF-ASSEMBLING POLYASPARTYLHYDRAZIDE COPOLYMER MICELLES FOR ANTICANCER DRUG DELIVERY.
2010
A new amphiphilic copolymer have been synthesized starting from the hydrosoluble polyaspartylhydrazide (PAHy) polymer, by grafting both hydrophilic PEG(2000) chains and hydrophobic palmitic acid (C(16)) moieties on polymer backbone, and the structure of obtained PAHy-PEG(2000)-C(16) copolymer have been characterized by 2D (1)H/(13)C NMR experiments. PAHy-PEG(2000)-C(16) copolymer showed the ability of self-assembling in aqueous media giving a core-shell structure and resulted potentially useful for encapsulating and dissolving hydrophobic drug. The formation of micellar core-shell structure has been investigated by 2D (1)H NMR NOESY experiments. The presence of cross-peaks for protons of C(…
Galactosylated micelles for a ribavirin prodrug targeting to hepatocytes.
2013
Polymeric micelles potentially able to carry to hepatocytes a ribavirin (RBV) prodrug, exploiting the presence of carbohydrate receptors, that is, ASGPR, were prepared starting from a galactosylated polylactide-polyaminoacid conjugate. This latter was obtained by chemical reaction of α,β-poly(N-2-hydroxyethyl) (2-aminoethylcarbamate)-dl-aspartamide (PHEA-EDA) with polylactic acid (PLA), and subsequent reaction with lactose, obtaining PHEA-EDA-PLA-GAL copolymer. To enhance the entrapment into obtained nanostructures, a hydrophobic RBV prodrug, that is, RBV tripalmitate, was synthesized and its capability to release RBV in the presence of an adequate enzymatic activity was demonstrated. Liver…
SELF-ASSEMBLED AMPHIPHILIC HYALURONIC ACID GRAFT COPOLYMERS FOR TARGETED RELEASE OF ANTITUMORAL DRUG
2009
Polymeric micelles obtained by self-assembling of amphiphilic hyaluronic acid (HA) graft copolymers have been prepared and characterized. In particular, hyaluronic acid (HA) has been grafted to polylactic acid (PLA) and polyethylenglycol chains (PEG), then the copolymers able to form micelles in aqueous medium have been chosen to entrap the antitumoral drug Doxorubicin. The critical aggregation concentration of HA-g-PLA or HA-g-PLA-g-PEG micelles has been determined by using pyrene as a fluorescent probe, whereas their shape and size have been evaluated by light scattering measurements, scanning and transmission electron microscopies. The selective cytotoxicity of drug loaded micelles towar…
Self-assembling and auto-crosslinkable hyaluronic acid hydrogels with a fibrillar structure
2008
Abstract A hyaluronic acid derivative bearing pendant l -benzoyl-cysteine portions (with a derivatization degree equal to 10 mol.%) was synthesized by linking N,N′-dibenzoyl- l -cystine to the polysaccharide and then reducing its disulfide bridge to thiol groups. The formation of π–π stacking interactions between the benzoyl moieties was studied by fluorescence spectroscopy as a function of polymer concentration and oxidation time. The efficiency of oxidation of thiol groups to disulfide bridges occurring in phosphate buffer pH 7.4, was determined by colorimetric assays. The hydrogel formed by means of oxidative crosslinking has shown the presence of fibrillar aggregates as detected by ligh…
Smart copolymer coated SPIONs for colon cancer chemotherapy
2019
Human colon cancer is one of the higher aggressive solid tumors, whose high mortality, much like many other solid tumors, results from metastasis formation. To reduce this high mortality, more effective chemotherapy, allowing a specific tumor accumulation and an efficient early-stage medical imaging as well, are still needed. At this regard, stimuli-responsive nanocarriers for anticancer drug delivery are promising strategy in cancer therapy. For this purpose, a dual targeted redox-responsive drug delivery system, prepared by coating superparamagnetic nanoparticles (SPIONs) with the amphiphilic copolymer INU-LA-PEG-FA and loading doxorubicin (DOXO-SPIONs) was investigated as tool for solid …
Evaluation of thermoresponsive properties and biocompatibility of polybenzofulvene aggregates for leuprolide delivery
2012
Abstract In this study, a polybenzofulvene derivative named poly-6-MOEG-9-BF3k, was evaluated as polymeric material for the production of injectable thermoresponsive nano-aggregates able to load low molecular weight peptidic drug, like the anticancer leuprolide. Thermoresponsive behavior of poly-6-MOEG-9-BF3k was studied in aqueous media by evaluating scattering intensity variations by means of DLS in function of temperature. Zeta potential measurements and SEM observations were also carried out. Moreover, critical aggregation temperature of the poly-6-MOEG-9-BF3k polymer was evaluated by pyrene fluorescence analysis. Then, the ability of prepared thermoresponsive aggregates to protect this…
Fluorinated and pegylated polyaspartamide derivatives to increase solubility and efficacy of Flutamide
2012
New fluorinated amphiphilic copolymers based on a biocompatible polyaspartamide have been prepared in order to obtain polymeric micelles useful for delivering anticancer drugs. In particular, α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) has been derivatized with polyethylene glycol (PEG(2000)) and ethylendiamine (EDA). Both these portions form the hydrophilic part of the copolymer, while the hydrophobic moiety is given by 1,2,4-oxadiazoles: 5-pentafluorophenyl-3-perfluoroheptyl-1,2,4-oxadiazole (PPOX) or 3-carboxyethyl-5-pentadecafluoroheptyl-1,2,4-oxadiazole (CPOX). Copolymers named PHEA-PEG(2000)-EDA-PPOX and PHEA-PEG(2000)-EDA-CPOX have been prepared with various degrees of derivati…
SYNTHESIS, PHYSICO-CHEMICAL AND BIOLOGICAL CHARACTERIZATION OF A PACLITAXEL MACROMOLECULAR PRODRUG
2004
Paclitaxel was attached to poly(hydroxyethylaspartamide) via a succinic spacer arm by a two-step protocol: (1) synthesis of 2'-O-succinyl-paclitaxel; (2) synthesis of PHEA-2'-O-succinyl-paclitaxel. The 2'-O-succinyl-paclitaxel derivative and the macromolecular conjugate were characterized by UV, IR, NMR and mass spectrometry analysis. The reaction yields were over 95% and the purity of products over 98%. Paclitaxel release and degradation from 2'-O-succinyl-paclitaxel occurred at a faster rate at pH 5.5 than 7.4. After 30 h of incubation at pH 5.5 and 7.4 the released free paclitaxel was about 40 and 20%, respectively. In plasma both drug release and degradation were found to occur at a hig…