Diselenide‐bearing crosslinked micelles‐reduced and stabilized gold nanoparticles in‐situ

Abstract

Gold nanoparticles (GNPs), usually fabricated through reduction and stabilization two steps, have been widely used in biomedical field. Here, the six-armed star copolymer was synthesized and self-assembled into crosslinked micelles for the in-situ preparation of GNPs in one-step without external reductant.The copolymer and their precursors were synthesized by a combination of ring-opening polymerization (ROP), activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP), and Michael addition reaction. Their molecular weights and structures were measured by gel permeation chromatography (GPC) and 1 H NMR. The diselenide bond of crosslinked micelles reduced AuCl 4 À to GNPs, and the crosslinked micelles stabilized the GNPs in-situ. Through increasing AuCl 4 À concentration, the collision probability between the GNPs increased, with particle diameters of 1.5, 2.3, and 3.0 nm. Moreover, the GNPs showed good stability, and the wavelength of maximum absorbance (λ max ) did not change under different dilution, temperature, and storage conditions. Furthermore, integrating dissipative particle dynamics (DPD) simulations and scripts with experiments, the formation process of crosslinked micelles, the stabilization process, and the size regulation of GNPs at mesoscopic scale were revealed. Therefore, this stable crosslinked micelles/GNPs hybrid material is expected to be used as a nanocarrier in an integrated diagnosis and treatment system.

Novel degradable amphiphilic 4-arm star PLA-b-POEOA and PLGA-b-POEOA block copolymers: synthesis, characterization and self-assembly

“…The synthesis of amphiphilic star BCPs by combining ROP and ATRP containing a polyester core and hydrophilic arms has been extensively reported, as these polymers can selfassemble in water, resulting in various nanostructures. 1,[22][23][24][25] The ability of such structures to encapsulate hydrophobic drugs, as well as their biodegradability, makes these polymers very valuable for drug delivery. 26 In the present study, a series of star-shaped and linear amphiphilic BCPs with different compositions were synthesized by combining ROP and ATRP (Scheme 1).…”