Search results for "Polyamine"
showing 10 items of 144 documents
Polyamines are increased in obese children and are related to markers of oxidative/nitrosative stress and angiogenesis.
2011
Polyamines (putrescine, spermidine, and spermine) are polycationic amines derived from arginine, which is the precursor of nitric oxide (NO). Due to the close relationship between the metabolism of polyamines and NO metabolism, the alteration in polyamine homeostasis can affect the NO bioavailability at the endothelium.The objective of the study was to test the hypothesis that childhood obesity is associated with a significant modification of blood polyamines and to investigate the presence of correlation between these molecules, circulating markers of oxidative and nitrosative stress, and endothelial dysfunction.This was an observational analytical case-control study conducted at one terti…
Self-assembled PAA-based nanoparticles as potential gene and protein delivery systems
2012
A series of nanoparticles is prepared via layer-by-layer assembly of oppositely charged, synthetic biocompatible polyamidoamine polymers as potential carriers. Particle size, surface charge and internal chain mobility are quantified as a function of the polymer type and number of layers. The effect of addition of surfactant is examined to simulate the effects of nanoparticle dissolution. The cyctotoxicity of these particles (in epithelia and murine cell lines) are orders of magnitude lower than polyethyleneimine controls. Stable nanoparticles may be prepared from mixtures of strongly, oppositely charged polymers, but less successfully from weakly charged polymers, and, given their acceptabl…
Poly-l-Lactic Acid Nanofiber-Polyamidoamine Hydrogel Composites: Preparation, Properties, and Preliminary Evaluation as Scaffolds for Human Pluripote…
2016
Electrospun poly-l-lactic acid (PLLA) nanofiber mats carrying surface amine groups, previously introduced by nitrogen atmospheric pressure nonequilibrium plasma, are embedded into aqueous solutions of oligomeric acrylamide-end capped AGMA1, a biocompatible polyamidoamine with arg-gly-asp (RGD)-reminiscent repeating units. The resultant mixture is finally cured giving PLLA-AGMA1 hydrogel composites that absorb large amounts of water and, in the swollen state, are translucent, soft, and pliable, yet as strong as the parent PLLA mat. They do not split apart from each other when swollen in water and remain highly flexible and resistant, since the hydrogel portion is covalently grafted onto the …
Degradable poly(amidoamine) hydrogels as scaffolds for in vitro culturing of peripheral nervous system cells.
2012
This paper reports on the synthesis and physico-chemical, mechanical, and biological characterization of two sets of poly(amidoamine) (PAA) hydrogels with potential as scaffolds for in vivo peripheral nerve regeneration. They are obtained by polyaddition of piperazine with N,N′-methylenebis(acrylamide) or 1,4-bis(acryloyl)piperazine with 1,2-diaminoethane as cross-linking agent and exhibit a combination of relevant properties, such as mechanical strength, biocompatibility, biodegradability, ability to induce adhesion and proliferation of Schwann cells (SCs) preserving their viability. Moreover, the most promising hydrogels, that is those deriving from 1,4-bis(acryloyl)piperazine, allow the …
Design and physicochemical characterization of poly(amidoamine) nanoparticles and the toxicological evaluation in human endothelial cells: applicatio…
2013
In this study, we investigated nanoparticles formulated by self-assembly of a biodegradable poly(amidoamine) (PAA) and a fluorescently labeled peptide, in their capacity to internalize in endothelial cells and deliver the peptide, with possible applications for brain drug delivery. The nanoparticles were characterized in terms of size, surface charge, and loading efficiency, and were applied on human cerebral microvascular endothelial cells (hCMEC/D3) and human umbilical vein endothelial cells (Huvec) cells. Cell-internalization and cytotoxicity experiments showed that the PAA-based nanocomplexes were essentially nontoxic, and the peptide was successfully internalized into cells. The result…
SYNTHESIS AND CHARACTERIZATION OF POLYAMINOACIDIC POLYCATIONS FOR GENE DELIVERY
2005
The properties as non viral gene vector of a protein-like polymer, the alpha,beta-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) were exploited after its derivatization with 3-(carboxypropyl)trimethyl-ammonium chloride (CPTA) as molecule bearing a cationic group, in order to obtain stable polycations able to condense DNA. PHEA was firstly functionalized with aminic pendant groups by reaction with ethylenediamine (EDA) obtaining the alpha,beta-poly(N-2-hydroxyethyl)(2-aminoethylcarbamate)-d,l-aspartamide (PHEA-EDA) copolymer. We demonstrated that polymer functionalization degree is easily modulable by varying reaction conditions, so allowing to produce two PHEA-EDA derivatives at different mo…
CROSSLINKED HYALURONAN WITH A PROTEIN-LIKE POLYMER: NOVEL BIORESORBABLE FILMS FOR BIOMEDICAL APPLICATIONS
2007
In this work, novel hydrogel films based on hyaluronan (HA) chemically crosslinked with the alpha,beta-poly(N-2-hydroxyethyl) (2-aminoethylcarbamate)-D,L-aspartamide (PHEA-EDA) were produced by solution casting method. The goal was to exploit both the biological key role of HA in tissue repair and regeneration, and the versatility of a synthetic protein-like polymer as the PHEA-EDA, in order to obtain biomaterials with physicochemical and biological properties suitable for a clinical use. By varying the molar ratio between the PHEA-EDA amino groups and HA carboxyl groups, three different films were obtained and characterized. Particularly FTIR, swelling, hydrolysis, and enzymatic degradatio…
Inhibition of the dimorphic transition of Candida albicans by the ornithine decarboxylase inhibitor 1,4-diaminobutanone: alterations in the glycoprot…
1990
Hyphal development in Candida albicans was selectively blocked by the ornithine decarboxylase competitive inhibitor 1,4-diaminobutanone (DAB). Inhibition of hyphal development required DAB during both yeast inoculum growth and subsequent incubation at 37 degrees C to induce mycelial growth. This effect was not due to general growth inhibition since DAB did not inhibit yeast growth, and reduced protein synthesis by 30% at most. Moreover, protein synthesis was unaffected by DAB when cells were pre-grown in drug-containing media. Since DAB inhibited dimorphic transition at 37 degrees C, morphology- and temperature-dependent protein synthesis could be distinguished. DAB stimulated the synthesis…
In vitro leishmanicidal activity of pyrazole-containing polyamine macrocycles which inhibit the Fe-SOD enzyme of Leishmania infantum and Leishmania b…
2014
The in vitro leishmanicidal activity and cytotoxicity of pyrazole-containing macrocyclic polyamines 1-4 was assayed on Leishmania infantum and Leishmania braziliensis species. Compounds 1-4 were more active and less toxic than glucantime and both infection rates and ultrastructural alterations confirmed that 1 and 2 were highly leishmanicidal and induced extensive parasite cell damage. Modifications in the excretion products of parasites treated with 1-3 were also consistent with substantial cytoplasm alterations. Compound 2 was highlighted as a potent inhibitor of Fe-SOD in both species, whereas its effect on human CuZn-SOD was poor. Molecular modelling suggested that 2 could deactivate Fe…
Oxaaza cyclophanes in the recognition of nucleotides. The role of oxygen and electron-rich aromatic rings
2007
Dioxapolyaza cyclophanes derived from resorcinol and different polyamine chains have been studied in aqueous solution as abiotic receptors for nucleotides. The presence of the additional ethyleneoxy subunits is reflected in a higher basicity and in a significant increase in the log K values for the interaction with nucleotides relative to that of related polyazacyclophanes.