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© 2016 Acta Materialia Inc.Poly(aspartic acid) (PASP) derivatives with adjustable pH-dependent solubility were synthesized and characterized to establish the relationship between their structure and solubility in order to predict their applicability as a basic material for enteric coatings. Polysuccinimide, the precursor of PASP, was modified with short chain alkylamines, and the residual succinimide rings were subsequently opened to prepare the corresponding PASP derivatives. Study of the effect of the type and concentration of the side groups on the pH-dependent solubility of PASP showed that solubility can be adjusted by proper selection of the chemical structure. The Henderson–Hasselbalch (HH) and the extended HH equations were used to describe the pH-dependent solubility of the polymers quantitatively. The estimate provided by the HH equation is poor, but an accurate description of the pH-dependent solubility can be found with the extended HH equation. The dissolution rate of a polymer film prepared from a selected PASP derivative was determined by fluorescence marking. The film dissolved rapidly when the pH was increased above its pKa. Cellular viability tests show that PASP derivatives are non-toxic to a human cell line. These polymers are thus of great interest as starting materials for enteric coatings. Statement of Significance Poly(amino acid) type biocompatible polymers were synthesized for future use as pharmaceutical film coatings. To this end, we tailored the pH-dependent solubility of poly(aspartic acid) (PASP). It was found that both the solubility and the pKa values of the modified PASP depended strongly on composition. Fluorescent marking was used to characterize the dissolution of a chosen PASP derivative. In acidic media only a negligible amount of the polymer dissolved, but dissolution was very fast and complete at the pH values that prevail in the small intestine. As a consequence, enteric coatings based on such PASP derivatives may be used fo

© 2016 Elsevier B.V.A series of 14 cationic derivatives of poly(aspartic acid) i.e. cationic polyaspartamides with different (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups was synthesized by nucleophilic addition on polysuccinimide. The resulting polyaspartamides have moderate amphiphilic properties. Relationships between the structure and ratio of side groups and in vitro properties of polyaspartamides, including their cytotoxic and membrane-damaging activity towards human cell lines, primary skin fibroblasts and erythrocytes, were established and discussed. Cationic polyaspartamides vary in their DNA-binding, condensing and nuclease-protecting characteristics depending on the concentration ratio of (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups. Effective cell transfection was achieved upon polyaspartamide-mediated plasmid DNA delivery in serum-free medium in the presence of chloroquine. Effect of serum proteins adsorption onto polyaspartamide based polyplexes, and the role of concentration of polyplexes in culture medium in their colloidal stability and transfection process were demonstrated. Synthesized polyaspartamides are biocompatible and long-acting gene carriers, which are applied to cells after dilution and without washing, thus providing transfection level comparable to that of commercial transfection reagent.

© 2017 Elsevier Ltd.Polyaspartamides with dialkylaminoalkyl and short chain alkyl side groups were synthesized and characterized in order to prepare polymer films. Their structure was confirmed by nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy and their thermal decomposition temperature (Td) was determined by thermogravimetric analysis. The composition of the polymers was adjusted to obtain polyaspartamides with glass transition temperatures (Tg) at around room temperature and the relationship between the structure and the properties was examined. The dissolution profile of polymer films made of polyaspartamides was measured with the help of fluorescent marking to show that dissolution rate of the films depends on the pH and can be controlled by the composition of the polymers.

© 2017 Elsevier Ltd Polyaspartamides with dialkylaminoalkyl and short chain alkyl side groups were synthesized and characterized in order to prepare polymer films. Their structure was confirmed by nuclear magnetic resonance ( 1 H NMR) and Fourier transform infrared (FTIR) spectroscopy and their thermal decomposition temperature (T d ) was determined by thermogravimetric analysis. The composition of the polymers was adjusted to obtain polyaspartamides with glass transition temperatures (T g ) at around room temperature and the relationship between the structure and the properties was examined. The dissolution profile of polymer films made of polyaspartamides was measured with the help of fluorescent marking to show that dissolution rate of the films depends on the pH and can be controlled by the composition of the polymers.

© 2017 Elsevier Ltd Polyaspartamides with dialkylaminoalkyl and short chain alkyl side groups were synthesized and characterized in order to prepare polymer films. Their structure was confirmed by nuclear magnetic resonance ( 1 H NMR) and Fourier transform infrared (FTIR) spectroscopy and their thermal decomposition temperature (T d ) was determined by thermogravimetric analysis. The composition of the polymers was adjusted to obtain polyaspartamides with glass transition temperatures (T g ) at around room temperature and the relationship between the structure and the properties was examined. The dissolution profile of polymer films made of polyaspartamides was measured with the help of fluorescent marking to show that dissolution rate of the films depends on the pH and can be controlled by the composition of the polymers.

© 2016 Acta Materialia Inc.Poly(aspartic acid) (PASP) derivatives with adjustable pH-dependent solubility were synthesized and characterized to establish the relationship between their structure and solubility in order to predict their applicability as a basic material for enteric coatings. Polysuccinimide, the precursor of PASP, was modified with short chain alkylamines, and the residual succinimide rings were subsequently opened to prepare the corresponding PASP derivatives. Study of the effect of the type and concentration of the side groups on the pH-dependent solubility of PASP showed that solubility can be adjusted by proper selection of the chemical structure. The Henderson–Hasselbalch (HH) and the extended HH equations were used to describe the pH-dependent solubility of the polymers quantitatively. The estimate provided by the HH equation is poor, but an accurate description of the pH-dependent solubility can be found with the extended HH equation. The dissolution rate of a polymer film prepared from a selected PASP derivative was determined by fluorescence marking. The film dissolved rapidly when the pH was increased above its pKa. Cellular viability tests show that PASP derivatives are non-toxic to a human cell line. These polymers are thus of great interest as starting materials for enteric coatings. Statement of Significance Poly(amino acid) type biocompatible polymers were synthesized for future use as pharmaceutical film coatings. To this end, we tailored the pH-dependent solubility of poly(aspartic acid) (PASP). It was found that both the solubility and the pKa values of the modified PASP depended strongly on composition. Fluorescent marking was used to characterize the dissolution of a chosen PASP derivative. In acidic media only a negligible amount of the polymer dissolved, but dissolution was very fast and complete at the pH values that prevail in the small intestine. As a consequence, enteric coatings based on such PASP derivatives may be used fo

© 2016 Elsevier B.V.A series of 14 cationic derivatives of poly(aspartic acid) i.e. cationic polyaspartamides with different (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups was synthesized by nucleophilic addition on polysuccinimide. The resulting polyaspartamides have moderate amphiphilic properties. Relationships between the structure and ratio of side groups and in vitro properties of polyaspartamides, including their cytotoxic and membrane-damaging activity towards human cell lines, primary skin fibroblasts and erythrocytes, were established and discussed. Cationic polyaspartamides vary in their DNA-binding, condensing and nuclease-protecting characteristics depending on the concentration ratio of (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups. Effective cell transfection was achieved upon polyaspartamide-mediated plasmid DNA delivery in serum-free medium in the presence of chloroquine. Effect of serum proteins adsorption onto polyaspartamide based polyplexes, and the role of concentration of polyplexes in culture medium in their colloidal stability and transfection process were demonstrated. Synthesized polyaspartamides are biocompatible and long-acting gene carriers, which are applied to cells after dilution and without washing, thus providing transfection level comparable to that of commercial transfection reagent.

© 2017 Elsevier Ltd.Polyaspartamides with dialkylaminoalkyl and short chain alkyl side groups were synthesized and characterized in order to prepare polymer films. Their structure was confirmed by nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy and their thermal decomposition temperature (Td) was determined by thermogravimetric analysis. The composition of the polymers was adjusted to obtain polyaspartamides with glass transition temperatures (Tg) at around room temperature and the relationship between the structure and the properties was examined. The dissolution profile of polymer films made of polyaspartamides was measured with the help of fluorescent marking to show that dissolution rate of the films depends on the pH and can be controlled by the composition of the polymers.