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

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 1H NMR and 2D-NOESY spectroscopy. The 1H 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 1H 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.

Preparation of self-assembled core–shell nano structure of conjugated generation 4.5 poly (amidoamine) dendrimer and monoclonal Anti-IL-6 antibody as bioimaging probe

“…6revealed two reflection peaks, as a broad shoulder peak at 2θ = 8.4°, with a d-spacing value of 1.05 nm.This signal reflects additional phase in the G4.5/IL-6 conjugate and presence of layer structure.Furthermore, the d-spacing of G4.5 (d = 0.42 nm) shifted slightly in comparison to G4.5/IL-6 conjugate (d = 0.44 nm) as the result of electrostatic interactions and hydrogen bonding between functionalized carboxyl groups of G4.5 and the amine residues of IL-6. Similar results were observed when anionic PAMAM dendrimers were reacted with cationic surfactants[5,34,35].…”

Poly(amido amine) dendrimers as absorption enhancers for oral delivery of camptothecin

“…It could also be due to hydrogen bonding between the drug and the dendrimer interior. Detailed 2D-NOESY NMR spectroscopy studies on the interaction of cationic PAMAM dendrimers and anionic guest molecules have demonstrated that there exists an inclusion complex of the anionic hydrophobic drug with the cationic PAMAM dendrimer in addition to the surface electrostatic interactions (Cheng et al, 2008b; Hu et al, 2009; Markowicz et al, 2012). Camptothecin formulated with carboxylate-terminated PAMAM G3.5 showed significantly less association with the dendrimer (Table 3).…”

A review of molecular imaging of atherosclerosis and the potential application of dendrimer in imaging of plaque

“…85,86 Typically, a dendrimer molecule is composed of the following three elements: an initiator core, interior layers, which are attached to the initiator core and are built of repeating units (number of the layers are expressed as generations), and multiple terminal functional groups. 87 Due to their unique characteristics, utilization of dendrimers in nanobiotechnology, such as bio-mimicry, diagnostics, and therapeutics, has attracted great attention of researchers over the past decade.…”