1,721,255 research outputs found
Poly(amidoamine)s : past, present, and perspectives
No full textA review. Poly(amidoamine)s (PAAs) are a family of synthetic polymers obtained by stepwise polyaddn. of prim- or sec-amines to bisacrylamides. Nearly all conceivable bisacrylamides and prim- or sec-amines can be employed as monomers endowing PAAs of a structural versatility nearly unique among stepwise polyaddn. polymers. PAAs are degradable in aq. media, including physiol. fluids. Many of them are remarkably biocompatible notwithstanding their cationic character. PAAs are per se highly functional polymers and, in addn., can be further functionalized giving rise to an endless variety of polymeric structures meeting the requisites for applications in such apparently disparate fields as inorg. water pollutants scavengers, sensors, drug and protein intracellular carriers, transfection promoters, peptidomimetic antiviral and antimalarial agents. In this review, the unique chem. of PAAs is discussed and a vast library of PAA structures and PAA applications from the beginning to the present days reported
NEW FUNCTIONAL POLYMERS FOR MEDICAL APPLICATIONS
No full textRecent results on both cationic and anionic functional polymers and macromonomers obtained by Michael-type polyaddition reactions as well as a new method for obtaining sec-amino-end-functionalized PEG, are described. The new families of macromolecular substances include poly(ethyleneglycol-amido-amine-urethanes) (PEGAAU), block copolymers between poly(ethyleneglycols) and poly(amido-amines) (PEG-PAA), block copolymers - between poly(ethyleneglycols) and poly(amido-thioether-amines) (PEG-PATA), and poly(thioether-amido-acids) (PTAA). Crosslinked, potentially hydrolyzable carboxylated resins based on the last family are also reported. The new polymers and macromonomers are mainly intended for surface-modification of common materials and biomaterials through surface-grafting
Poly(amidoamine) Conjugates Containing Doxorubicin Bound via an Acid-Sensitive Linker.
Full text linkPoly(amidoamine)s with amino pendant groups were prepared by hydrogen-transfer polyaddition of primary and secondary amines to bis-acrylamines. Dansyl cadaverine (DC) doxorubicin (Dox) were bound to the polymers via a cis-aconityl spacer to give conjugates containing 3 µg of DC per mg of polymer and 28 to 35 µg of Dox per mg of polymer. Release of DC and Dox at physiological and acidic pH varied from 0 to 35% over 48 h and was pH dependent. Although the ISA1Dox conjugate (IC50 = 6 µg Dox · mL-1) presented similar toxicity as the parent polymer without Dox, ISA23Dox showed increased toxicity (IC50 = 10 µg Dox · mL-1). These results suggest that ISA23Dox is able to release biologically active Dox in vitro and that this conjugate might be suitable for further development
POLY(ESTERTHIOETHERAMINES), A NEW FAMILY OF TERTIARY AMINO POLYMERS
No full textThe aim of this letter is to report some preliminary results on the synthesis of a new family of tertiary amino polymers, poly(esterthioetheramines), as part of a wider research work on synthetic polymers containing the aminic function in the main chain. These new polymers can be obtained by stepwise polyaddition of bis( beta -mercaptoethylamines) to bisacrylic esters. The aminic comonomers, in turn, can be synthesized by ring opening addition reaction of bis secondary amines to ethylene sulfide. In this letter, the authors limited their investigation to bis( beta -mercaptoethylpiperazine) and a few selected bisacrylic estres. They gathered experimental evidence that both monomers and polymers synthesis can be considered as general, thus opening the way to a new family of macromolecular substances having potential interest both in the biomedical field, and as polymeric liquid crystals, as many tertiary amino polymers, and thioether polymers do. 14 Refs
Guanidine substituted polyamidoamine hydrogels as scaffolds for cell culturing and tissue regeneration
No full textIntracellular fate of bioresponsive poly(amidoamine)s in vitro and in vivo
Full text linkLinear poly(amidoamine)s (PAAs) have been designed to exhibit minimal non-specific toxicity, display pH-dependent membrane lysis and deliver genes and toxins in vitro. The aim of this study was to measure PAA cellular uptake using ISA1-OG (and as a reference ISA23-OG) in B16F10 cells in vitro and, by subcellular fractionation, quantitate intracellular trafficking of (125)I-labelled ISA1-tyr in liver cells after intravenous (i.v.) administration to rats. The effect of time after administration (0.5-3h) and ISA1 dose (0.04-100mg/kg) on trafficking, and vesicle permeabilisation (N-acetyl-b-D-glucosaminidase (NAG) release from an isolated vesicular fraction) were also studied. ISA1-OG displayed approximately 60-fold greater B16F10 cell uptake than ISA23-OG. Passage of ISA1 along the liver cell endocytic pathway caused a transient decrease in vesicle buoyant density (also visible by TEM). Increasing ISA1 dose from 10mg/kg to 100mg/kg increased both radioactivity and NAG levels in the cytosolic fraction (5-10 fold) at 1h. Moreover, internalised ISA1 provoked NAG release from an isolated vesicular fraction in a dose-dependent manner. These results provide direct evidence, for the first time, of PAA permeabilisation of endocytic vesicular membranes in vivo, and they have important implications for potential efficacy/toxicity of such polymeric vectors
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