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Evaluation of poly(amidoamine) dendrimers as potential carriers of iminodiacetic derivatives using solubility studies and 2D-NOESY NMR spectroscopy.

Markowicz M, Szymański P, Ciszewski M, Kłys A, Mikiciuk-Olasik E - J Biol Phys (2012)

Bottom Line: We reported that PAMAM dendrimers contribute to significant solubility enhancement of iminodiacetic acid analogues.The 2D-NOESY analysis revealed interactions between the primary amine groups of PAMAM dendrimers and the analogues of iminodiacetic acid.The results of solubility studies together with (1)H NMR and 2D-NOESY experiments suggest that the interactions between PAMAM dendrimers of generation 1-4 and derivatives of iminodiacetic acid are based on electrostatic interactions and internal encapsulation.Electronic supplementary material The online version of this article (doi:10.1007/s10867-012-9277-5) contains supplementary material, which is available to authorized users.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Chemistry and Drug Analysis, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland.

ABSTRACT
The interactions between dendrimers and different types of drugs are nowadays one of the most actively investigated areas of the pharmaceutical sciences. The interactions between dendrimers and drugs can be divided into: internal encapsulation, external electrostatic interaction, and covalent conjugation. In the present study, we investigated the potential of poly(amidoamine) (PAMAM) dendrimers for solubility of four iminodiacetic acid derivatives. We reported that PAMAM dendrimers contribute to significant solubility enhancement of iminodiacetic acid analogues. The nature of the dendrimer-drug complexes was investigated by (1)H NMR and 2D-NOESY spectroscopy. The (1)H NMR analysis proved that the water-soluble supramolecular structure of the complex was formed on the basis of ionic interactions between terminal amine groups of dendrimers and carboxyl groups of drug molecules, as well as internal encapsulation. The 2D-NOESY analysis revealed interactions between the primary amine groups of PAMAM dendrimers and the analogues of iminodiacetic acid. The results of solubility studies together with (1)H NMR and 2D-NOESY experiments suggest that the interactions between PAMAM dendrimers of generation 1-4 and derivatives of iminodiacetic acid are based on electrostatic interactions and internal encapsulation.Electronic supplementary material The online version of this article (doi:10.1007/s10867-012-9277-5) contains supplementary material, which is available to authorized users.

No MeSH data available.


Solubility of compound 4 at different concentrations and generations of PAMAM dendrimers
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Fig5: Solubility of compound 4 at different concentrations and generations of PAMAM dendrimers

Mentions: In our study, the effect of G2–G4 PAMAM dendrimers on the process of solubilization was also investigated. Obtained results are shown in Figs. 2, 3, 4, and 5, from which it is clear that the solubility of iminodiacetic acid derivatives was affected by concentration and generation of PAMAM dendrimers. The solubility of all compounds was the highest in the presence of G4 PAMAM dendrimers, presumably due to the fact that the number of primary and tertiary amines in the dendrimer increases with generation size. Thus, a dendrimer of a higher generation has a tendency to interact with more particles of a hydrophobic compound more than do lower generation dendrimers. Tables S1–S4 (see supporting information) present the mean concentrations of drugs 1–4 in the presence of PAMAM dendrimers as well as standard deviations (SD) for all the data.Fig. 2


Evaluation of poly(amidoamine) dendrimers as potential carriers of iminodiacetic derivatives using solubility studies and 2D-NOESY NMR spectroscopy.

Markowicz M, Szymański P, Ciszewski M, Kłys A, Mikiciuk-Olasik E - J Biol Phys (2012)

Solubility of compound 4 at different concentrations and generations of PAMAM dendrimers
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3473130&req=5

Fig5: Solubility of compound 4 at different concentrations and generations of PAMAM dendrimers
Mentions: In our study, the effect of G2–G4 PAMAM dendrimers on the process of solubilization was also investigated. Obtained results are shown in Figs. 2, 3, 4, and 5, from which it is clear that the solubility of iminodiacetic acid derivatives was affected by concentration and generation of PAMAM dendrimers. The solubility of all compounds was the highest in the presence of G4 PAMAM dendrimers, presumably due to the fact that the number of primary and tertiary amines in the dendrimer increases with generation size. Thus, a dendrimer of a higher generation has a tendency to interact with more particles of a hydrophobic compound more than do lower generation dendrimers. Tables S1–S4 (see supporting information) present the mean concentrations of drugs 1–4 in the presence of PAMAM dendrimers as well as standard deviations (SD) for all the data.Fig. 2

Bottom Line: We reported that PAMAM dendrimers contribute to significant solubility enhancement of iminodiacetic acid analogues.The 2D-NOESY analysis revealed interactions between the primary amine groups of PAMAM dendrimers and the analogues of iminodiacetic acid.The results of solubility studies together with (1)H NMR and 2D-NOESY experiments suggest that the interactions between PAMAM dendrimers of generation 1-4 and derivatives of iminodiacetic acid are based on electrostatic interactions and internal encapsulation.Electronic supplementary material The online version of this article (doi:10.1007/s10867-012-9277-5) contains supplementary material, which is available to authorized users.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Chemistry and Drug Analysis, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland.

ABSTRACT
The interactions between dendrimers and different types of drugs are nowadays one of the most actively investigated areas of the pharmaceutical sciences. The interactions between dendrimers and drugs can be divided into: internal encapsulation, external electrostatic interaction, and covalent conjugation. In the present study, we investigated the potential of poly(amidoamine) (PAMAM) dendrimers for solubility of four iminodiacetic acid derivatives. We reported that PAMAM dendrimers contribute to significant solubility enhancement of iminodiacetic acid analogues. The nature of the dendrimer-drug complexes was investigated by (1)H NMR and 2D-NOESY spectroscopy. The (1)H NMR analysis proved that the water-soluble supramolecular structure of the complex was formed on the basis of ionic interactions between terminal amine groups of dendrimers and carboxyl groups of drug molecules, as well as internal encapsulation. The 2D-NOESY analysis revealed interactions between the primary amine groups of PAMAM dendrimers and the analogues of iminodiacetic acid. The results of solubility studies together with (1)H NMR and 2D-NOESY experiments suggest that the interactions between PAMAM dendrimers of generation 1-4 and derivatives of iminodiacetic acid are based on electrostatic interactions and internal encapsulation.Electronic supplementary material The online version of this article (doi:10.1007/s10867-012-9277-5) contains supplementary material, which is available to authorized users.

No MeSH data available.