Host−Guest Chemistry of Dendrimer-Drug Complexes. 2. Effects of Molecular Properties of Guests and Surface Functionalities of Dendrimers

Abstract

The host-guest chemistry of dendrimer-drug complexes is investigated by NMR techniques, including (1)H NMR and 2D-NOESY studies. The effects of molecular properties of drug molecules (protonation ability and spatial steric hindrance of charged groups) and surface functionalities of dendrimers (positively charged amine groups and negatively charged carboxylate groups) on the host-guest interactions are discussed. Different interaction mechanisms between dendrimers and drug molecules are proposed on the basis of NMR results. Primary amine- and secondary amine-containing drugs preferentially bind to negatively charged dendrimers by strong electrostatic interactions, whereas tertiary amine and quaternary ammonium-containing drugs have weak binding ability with dendrimers due to relatively low protonation ability of the tertiary amine group and serious steric hindrance of the quaternary ammonium group. Positively charged drugs locate only on the surface of negatively charged dendrimers, whereas negatively charged drugs locate both on the surface and in the interior cavities of positively charged dendrimers. The host-guest chemistry of dendrimer-drug complexes is promising for the development of new drug delivery systems.

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].…”

RGD peptide-modified multifunctional dendrimer platform for drug encapsulation and targeted inhibition of cancer cells

“…To better understand the in vitro drug release mechanism under different pH conditions, NMR techniques have been used to investigate the host-guest interaction between DOX molecules and the dendrimer platform [64]. The influence of the pH on the interaction between the G5.NHAc-FI-PEG-RGD dendrimer and DOX·HCl in D 2 O was first investigated via 1D 1 H NMR experiments (Fig.…”

Multiscale Modeling for Host-Guest Chemistry of Dendrimers in Solution

“…The binding strength between dendrimer-guest complexes has been determined by isothermal titration calorimetry(ITC) [26][27][28][29], high performance liquid chromatography (HPLC) [30] and fluorescence spectroscopy [31][32][33]. Detailed conformations of dendrimers interacting with guest molecules have been studied by nuclear magnetic resonance(NMR) [34][35][36] and the size of the dendrimer-guest complexes has been measured by dynamic light scattering (DLS) [22,31]. For instance, supramolecular assemblies of polyamidoamine (PAMAM) dendrimers and phenanthrene, an organic pollutant, have been studied using fluorescence resonance energy transfer (FRET) to understand the interaction between dendrimers and guest molecules in aqueous solution [24].…”