A Biological Strategy for Fabrication of Au/EGFP Nanoparticle Conjugates Retaining Bioactivity

Abstract

Recently, it has been found that thiolated oligonucleotides can be used to direct the assembly of gold colloids into ordered functional nanostructures. However, approaches for fabricating Au/DNA conjugates by using a linear, functional, double-stranded (ds) DNA fragment that directly binds to a Au NP surface have not been reported. In this paper, we used a ligase-dependent strategy to synthesize a 1.7 kb, thiolated dsDNA fragment and generated novel nanocrystals by coupling it to 13 nm Au NPs. The conjugates contained Au/EGFP with EGFP/Au molar ratios of 1:1, 2:1, and 3:1, as determined by their electrophoretic mobility and AFM imaging. The Au/EGFP nanoconjugates could still be digested by restriction endonuclease (RE) and expressed as functional proteins in mammalian cells, indicating the biological activities of DNA fragments were retained after conjugation with Au NPs. This biological strategy for fabrication of Au/DNA conjugates may be applied to molecular imaging, nanomedicine, and nanobiosensor technology.

Monolayer coated gold nanoparticles for delivery applications

“…A new approach has been reported to conjugate thiolated double-stranded (ds) DNA fragments (EGFP) directly to AuNPs using ligase-dependent strategy [91]. The Au-EGFP nanoconjugates could be digested by restriction enzymes and expressed as functional proteins inside mammalian cells, demonstrating retained activity of the dsDNA conjugated to AuNPs.…”

Size-Dependent Attenuation of TLR9 Signaling by Gold Nanoparticles in Macrophages

“…Gold nanoparticles (GNPs), also known as colloidal gold, have been recommended for the treatment of various diseases since the Middle Ages, although the active mechanism still remains poorly understood (11). GNP has many advantageous properties such as chemical stability, a highly electrondense core, ease of manipulation of size and shape, and ease of conjugation to drugs and biomolecules (12)(13)(14)(15)(16). These characteristics make it a good candidate for the design of protein blockers and drug carriers.…”

Increased apoptotic potential and dose‐enhancing effect of gold nanoparticles in combination with single‐dose clinical electron beams on tumor‐bearing mice

“…(17) Gold nanoparticles have been actively investigated in a wide variety of biomedical applications due to their biocompatibility and ease of conjugation to biomolecules. (18)(19)(20)(21) Besides, nanoparticles have the advantages of small size (1-100 nm) and ability to evade the immune system, (22,23) and also have been shown to preferentially accumulate in tumors. (24)(25)(26)(27)(28) While previous studies have primarily examined the dose enhancement factor by Au, it is also known that radiationinduced apoptosis is a significant component of radiation-induced cell death.…”