Preparation of near-infrared light absorbing gold nanoparticles using polyethylene glycol-attached dendrimers.

The photochemical properties of gold nanoparticles (Au NPs) are largely influenced by their size and morphology. Stably dispersed Au NPs that absorb near-infrared (NIR) light are useful for biomedical applications. We prepared well-dispersed NIR-absorbing Au NPs using seeding growth from Au NPs encapsulated in polyethylene glycol (PEG)-attached dendrimers.

PEG-attached PAMAM dendrimers encapsulating gold nanoparticles: growing gold nanoparticles in the dendrimers for improvement of their photothermal properties.

Recently, we demonstrated that loading of HAuCl(4) in poly(ethylene glycol) (PEG)-attached poly(amidoamine) (PAMAM) G4 dendrimers and subsequent reduction with NaBH(4) yield dendrimers encapsulating gold nanoparticles (Au NPs), which have photoinduced heat-generating properties. This study was undertaken to enhance photothermal properties of the Au NP-incorporated PEG-attached dendrimers by growing Au NPs in the dendrimers. Repeated loading of HAuCl(4) in the PEG-attached dendrimers and subsequent reduction with NaBH(4) enhanced the surface plasmon resonance, indicating that Au NPs were grown in the PEG-attached dendrimers using that procedure.

X-ray computed tomography contrast agents prepared by seeded growth of gold nanoparticles in PEGylated dendrimer.

Gold nanoparticles (Au NPs) are a potential x-ray computed tomography (CT) contrast agent. A biocompatible and bioinactive surface is necessary for application of gold nanoparticle to CT imaging. Polyethylene glycol (PEG)-attached dendrimers have been used as a drug carrier with long blood circulation.

Influence of dendrimer generation and polyethylene glycol length on the biodistribution of PEGylated dendrimers.

Dendrimers are a potential drug carrier. Because modification with polyethylene glycol (PEG) is known to improve the blood retention, PEGylated dendrimers have been studied as a useful drug carrier. In this study, three types of PEGylated L-lysine-bearing polyamidoamine dendrimers (PEG2k-Lys-PAMAM (G4), PEG5k-Lys-PAMAM (G4), PEG2k-Lys-PAMAM (G5)) were synthesized, which are composed of a dendrimer of different generations (generations 4 and 5) and PEG chains with different molecular weights (2k and 5k).