Facile phase transfer of hydrophobic nanoparticles with poly(ethylene glycol) grafted hyperbranched poly(amido amine)

Abstract

In order to enhance the dispersion ability of hydrophobic nanoparticles in water while maintaining their unique properties, we utilized poly(ethylene glycol) grafted hyperbranched poly(amido amine) (h-PAMAM-g-PEG) to modify three types of hydrophobic nanoparticle, CdSe, Au, and Fe(3)O(4), and transferred them into water to extend their applications in biology. Considering the large amounts of amino groups in hyperbranched poly(amido amine) (h-PAMAM) polymer, complexation interaction between h-PAMAM-g-PEG copolymer and nanoparticles was achieved and ligand exchange between the copolymers and original small molecules ligands occurred. The transferred nanoparticles could be easily dispersed in water with better stability, and their unique properties, such as fluorescence, surface plasmon resonance, and superparamagnetism, were well maintained in the ligand exchange process. In addition, increasing the number of grafted PEG showed a negative effect on the ligand exchange process. Due to the existence of h-PAMAM-g-PEG ligands, the stabilized nanoparticles have improved stability in aqueous and ionic solutions. In the case of CdSe nanoparticles, the h-PAMAM-g-PEG layer leads to a lower cytotoxicity when compared with bare CdSe particles, and they could be directly used in bioimaging.

Molecular Dynamics Study of the Structure and Interparticle Interactions of Polyethylene Glycol-Conjugated PAMAM Dendrimers

“…PEGylated dendrimers have shown increased water solubility, extended periods of release of drug molecules, and have been successfully used as nonviral gene vectors targeting brain, breast and prostate cancers 15–23. However, experiments showing these potential applications have used different lengths of PEG chains and dendrimer sizes, which can affect the encapsulation efficiency 24.…”

Synthesis and intrinsic blue fluorescence study of hyperbranched poly(ester-amide-ether)

“…In recent years, a variety of hyperbranched fluorescent polymers have been prepared through many creative synthetic methods, including end-capping with traditional fluorophores such as N,N-dimethylaminobenzaldehyde [4][5][6], and pyrene [7]; building dendritic architectures possessing fluorescent groups such as aromatic carbazole [8], oxadizaole [9], triarylpyrazoline [10], and binaphtyl [11]; and encapsulated metallic fluorescent nanodots or dye molecules such as Au and CdSe nanodot [12], and fluorescein sodium [13]. The poly(amido amine) (PAMAM) and poly(propylene imine) (PPI) dendrimers were reported to emit the strong blue fluorescence.…”

Blue-emitting PEGylated hyperbranched PAMAM: transformation of cross-linked micelles to hollow spheres controlled by the PEG grafting density

“…The product was precipitated in diethyl ether for three times and kept in the sealed container for the next step. H-PAMAM-g-PEG copolymers were synthesized during the substitution reaction of succinimide groups of PEG-SC with amino groups (primary and secondary) of h-PAMAM [13]. 0.56 g of h-PAMAM (0.1 mmol) was mixed with 0.63 g of PEG-SC (0.3 mmol) in anhydrous DMF (25 mL).…”