Near-Infrared Photothermal Release of siRNA from the Surface of Colloidal Gold–Silver–Gold Core–Shell–Shell Nanoparticles Studied with Second-Harmonic Generation

Abstract

Photothermal release of oligonucleotides from the surface of plasmonic nanoparticles represents a promising platform for spatiotemporal controlled drug delivery. Here we demonstrate the use of novel gold–silver–gold core–shell–shell (CSS) nanoparticles to study the photothermal cleaving and release of micro-RNA (miRNA) mimics or small interfering RNA (siRNA) under nearinfrared (NIR) irradiation. The furan–maleimide-based Diels–Alder adduct cleaves thermally above 60 °C and is used to bind siRNA to the colloidal nanoparticle surface in water. We investigate the photothermal cleaving kinetics of siRNA under different NIR laser powers using surface-sensitive time-dependent second-harmonic generation (SHG) spectroscopy. The photothermal release of siRNA from the surface of CSS nanoparticles is significantly higher than that from the surface of gold nanoparticles (GNPs) under similar experimental conditions. These results demonstrate that plasmonic CSS nanoparticles with photothermal cleaving linkers have important potential applications for nanoparticle-based NIR-mediated drug-delivery systems.

Combinatorial Delivery of miRNA‐Nanoparticle Conjugates in Human Adipose Stem Cells for Amplified Osteogenesis

“…Representative SHG spectra, centered at 400 nm with a full‐width half‐maximum of approximately 4.5 nm, of SNP‐miR‐21 complex are shown in Figure A. The miRNA‐functionalized nanoparticles have higher SHG intensities than the corresponding nanoparticles without miRNA functionalization due to the increased surface charge density through the χ (3) effect, in agreement with our previous results . Upon irradiation at 400 nm, the SNP absorbed energy at the plasmon resonance, leading to the cleaving of the linker and release of miRNA mimic, resulting in a lower SHG intensity, as shown in Figure A.…”

“…SHG is dipole forbidden in centrosymmetric media, like bulk solution, but can be generated at the surface of nanoparticles where the symmetry is broken. Recently, SHG has been used as an accurate method to determine molecular adsorption and chemical reactions at nanoparticle surfaces, ion‐transport processes in liposomes, and the release of oligonucleotides from the surface of plasmonic nanoparticles …”

Photoactivatable Protherapeutic Nanomedicine for Cancer

“…The photogenerated heat can serve as a trigger to cleave the protherapeutics on or in the nanoparticles and potentiate cancer treatment. Therapeutics, including anticancer drugs [ 76 ] and siRNA [ 77 ] have been conjugated to the nanoparticles by thermal‐liable linkers, such as azo or bicyclic linker. For instance, Hu and co‐workers recently demonstrated a NIR‐controlled dual drug‐formulated switchable phototheranostic nanoparticle (CPT@DOX‐UCST/PPy) for cancer therapy ( Figure a).…”

“…Thereby, a siRNA analog, siRNA‐148b, was attached to the surface of the gold/silver/gold core/shell/shell (CSS) nanoparticles by a thermally cleavable bicyclic linker made by the Diels−Alder reaction. [ 77 ] Upon 800 nm laser irradiation, the CSS nanoparticles generated heat to increase the local temperature over 60 °C, and triggered the release of siRNA in a temperature‐dependent manner.…”

Green Synthesized Silver Nanoparticles of Myrtus communis L (AgMC) Extract Inhibits Cancer Hallmarks via Targeting Aldose Reductase (AR) and Associated Signaling Network

“…The size and morphology of synthesized metallic nanoparticles can be controlled with chemical reducing agents [1][2][3]. However, the reducing agents and solvents used in the synthesis of nanoparticles are hazardous or toxic to the environment [2].…”