Copper (Cu) nanoparticles possess unusual electrical, thermal, and optical properties. However, applications of these materials are often limited by their tendency to oxidize. We prepared Cu nanoparticles by a simple polyol method, with a good control over the particle size. The reaction required no inert atmosphere or surfactant agents. The as-prepared Cu nanoparticles showed good resistance to oxidation in solution. These Cu nanoparticles were then incorporated into a biocompatible polysaccharide hydrogel, which further stabilized the nanoparticles. The hybrid hydrogel exhibited a rapid self-healing ability. Because of the excellent photothermal conversion properties of the embedded Cu nanoparticles, the hybrid hydrogel showed rapid temperature elevation under laser irradiation. The hybrid hydrogel showed limited cytotoxicity; however, under laser irradiation the hydrogel displayed antibacterial properties owing to the heating effects. This study demonstrates that our hybrid hydrogel may have applications in biomedical fields and photothermal therapy.Keywords: antibacterial; hydrogel; nanoparticles; photothermal effect; self-healing;

⿢Biocompatible fluorescent hybrid nanoparticles were prepared via a green method.⿢Fluorescence enhancement can be observed due to the structure of the nanoparticles.⿢These nanoparticles exhibit targeted integrin detection property.In this work, green synthesis of a kind of fluorescent core-shell nanoparticles via a facile one-pot method was reported. We chose tryptophan, a common amino acid, to serve as the green reducing agent of the gold core. And a biomacromolecule, poly-(l-lysine), was then employed to assemble and cross-link onto gold nanoparticle surfaces serving as the biocompatible shell. Fluorescence enhancement was observed after a cyanine dye was conjugated onto the nanoparticle surfaces. Then, peptides with arginine-glycine-aspartic acid sequence were bound to the shell as targeting ligand. Cell imaging assay demonstrated that the prepared nanoparticles are efficient in target sensing of integrin-positive cells. Moreover, they possess high biocompatibility because of the green synthetic method. Thus, the prepared nanoparticles show great potential in cellular imaging and targeted integrin detection.Download high-res image (113KB)Download full-size image

In this work, a fluorescent hybrid core–shell nanoparticle was prepared by coating a functional polymer shell onto silver nanoparticles via a facile one-pot method. The biomolecule poly-l-lysine (PLL) was chosen as the polymer shell and assembled onto the silver core via the amine-reactive cross-linker, 3,3′-dithiobis(sulfosuccinimidylpropionate). The fluorescent anticancer drug, doxorubicin, was incorporated into the PLL shell through the same linkage. As the cross-linker possesses a thiol-cleavable disulfide bond, disassembly of the PLL shell was observed in the presence of glutathione, leading to controllable doxorubicin release. The silver core there provided an easily modified surface to facilitate the shell coating and ensures the efficient separation of as-prepared nanoparticles from their reaction mixture through centrifugation. Cell assays show that the prepared hybrid fluorescent nanoparticles can internalize into cells possessing excellent biocompatibility prior to the release of doxorubicin, terminating cancer cells efficiently as the doxorubicin is released at the intracellular glutathione level. Such properties are important for designing smart containers for target drug delivery and cellular imaging.Keywords: cellular imaging; core−shell nanoparticles; disassembly; fluorescence; polymer; self-assembly;