Liposomes as nanoreactors for the photochemical synthesis of gold nanoparticles

Abstract

A simple and novel method for the photochemical synthesis of AuNPs in liposomes is described. Gold salt is coencanpsulated with the photoinitiator Irgacure-2959 in POPC liposomes prepared via traditional thin-film hydration technique. UVA irradiation for 15 minutes results in encapsulated AuNPs of 2.8 ± 1.6 nm in diameter that are primarily dispersed in the aqueous interior of the liposomes.

Endocytosis-driven gold nanoparticle fractal rearrangement in cells and its influence on photothermal conversion

“…This treatment emphasizes the contribution of the internalized AuNPs to the absorption spectrum, eliminating the biological material-derived extinction spectrum. It is worth noting that we observed a secondary LSPR for the 11,16, and 30 nm-AuNPs in three cell types; however, the internalized 3 nm-AuNPs exhibited a single redshifted LSPR peak (Fig. 3).…”

“…12 Furthermore, AuNPs with different sizes might be internalized differently depending on the cell types of the tumor microenvironment, thereby conditioning their photothermal and photoacoustic efficiency, 13,14 as well as photodynamic therapy and radio-sensitization effects. 15 Gold nanoparticles are among the most exploited nanosized materials in biomedical approaches for cancer theranosis, [16][17][18] mostly due to the wide possibilities for chemical modification and tunable optical and thermal capacities. [19][20][21][22][23] The typically localized surface plasmon resonance (LSPR) peak in the transverse mode (∼525 nm) of spherical AuNPs limits their use in light-induced thermal ablation because the wavelengths needed to efficiently engage plasmon resonance fall within the visible spectrum; they show short tissue penetration capacity owing to the light scattering of the surrounding tissues and the absorption by natural chromophores.…”

Lipid Nanoparticles─From Liposomes to mRNA Vaccine Delivery, a Landscape of Research Diversity and Advancement

“…A recent application of LNPs is as nanoreactors, nanoscale chemical reactors applied to nanotechnology and nanobiotechnology. For example, LNPs have been used as nanoreactors for the size-controlled synthesis of metal nanoparticles. − Metal nanoparticles are used in electronics, biosensors, and catalysis and are also used in biomedical applications such as imaging, drug delivery, and photothermal therapy. The sizes of nanoparticles determine many of their properties; thus, control over metal nanoparticle size is important in controlling their properties and in determining their suitability for use.…”

Cationic Liposomes Enable Shape Control in Surfactant-Free Synthesis of Biocompatible Gold Nanorods

“…The starting point for developing a CTAB-free method to synthesize GNRs was a meld of the simple and high-yielding photochemical synthesis methods previously reported by Nishioka et al (2003) and Ahmed and Narain (2010) while also incorporating minor modifications adopted from our previous work with the photochemical synthesis of spherical GNPs inside 100 nm zwitterionic liposomes. − The starting GNP growth solution contained the following reactants: gold salt (HAuCl 4 , 1.6 mM), a shape-directing surfactant (CTAB, 66.3 mM), a source of Ag + ions to control the aspect ratio (AgNO 3 , 0.2 mM), a mild reducing agent (ascorbic acid, 2.2 mM), and a photoinitiator as a source of ketyl radicals required to reduce Au 3+ to Au 0 (I-2959, 0.6 mM). Sequentially mixing the above-mentioned reactants followed by irradiation with UVC light (254 nm) for 30 min resulted in a brown-colored sample whose absorption spectra displayed a strong longitudinal SPR band centered at ∼750 nm and a weak transverse SPR band at ∼528 nm, indicating the presence of anisotropic particles (Figure A, blue).…”