Synthesis of Gelatin-Stabilized Gold Nanoparticles and Assembly of Carboxylic Single-Walled Carbon Nanotubes/Au Composites for Cytosensing and Drug Uptake

Abstract

Gelatin-stabilized gold nanoparticles (AuNPs-gelatin) with hydrophilic and biocompatible were prepared with a simple and "green" route by reducing in situ tetrachloroauric acid in gelatin. The nanoparticles showed the excellent colloidal stability. UV-vis spectra, transmission electron microscopy (TEM), and atomic force microscopy revealed the formation of well-dispersed AuNPs with different sizes. By combination of the biocompatibility of AuNPs and excellent conductivity of carboxylic single-walled carbon nanotubes (c-SWNTs), a novel nanocomposite was designed for the immobilization and cytosensing of HL-60 cells at electrodes. The immobilized cells showed sensitive voltammetric response, good activity, and increased electron-transfer resistance. It can be used as a highly sensitive impedance sensor for HL-60 cells ranging from 1 x 10(4) to 1 x 10(7) cell mL(-1) with a limit of detection of 5 x 10(3) cell mL(-1). Moreover, the nanocomposite could effectively facilitate the interaction of adriamycin (ADR) with HL-60 cells and remarkably enhance the permeation and drug uptake of anticancer agents in the cancer cells, which could readily lead to the induction of the cell death of leukemia cells.

Effects of Au nanoparticles on thermoresponsive genipin-crosslinked gelatin hydrogels

“…This behavior apparently contrasts with the stabilizing effect previously reported for gelatin [20]. However, it should be noted that this stabilizing effect was reported for in situ prepared Au NPs, using gelatin as a reducing and stabilizing agent, thus in the absence of citrate anions [20]. Thus, it might be inferred that the Au NPs aggregation observed in this case arises from the interaction between the gelatin and the citrate capping.…”

“…The observation of a shoulder extending to higher wavelength in relation to the SPR band of the original colloid is an indication of Au NPs aggregation, probably mediated by the biopolymer chains, due to interparticle plasmon coupling. This behavior apparently contrasts with the stabilizing effect previously reported for gelatin [20]. However, it should be noted that this stabilizing effect was reported for in situ prepared Au NPs, using gelatin as a reducing and stabilizing agent, thus in the absence of citrate anions [20].…”

“…Examples of Au hydrogel nanocomposites are those of chitosan [17,18] and alginate [19]. Although there are a few reports on the preparation of Au gelatin nanocomposites [20,21], the effect of light-irradiated Au NPs on the release properties of the hydrogel has not been investigated. Moreover, there are no reports on the use of genipin for preparing crosslinked Au gelatin nanocomposites, despite its relevance in the context of new formulations for biocompatible hydrogels.…”

Time-dependent effect in green synthesis of silver nanoparticles

“…After this stage, the Ag-NPs could dissociate due to heating to form smaller particles stabilized by the amine pendant groups on the gelatin, which leads to the formation of gelatin-stabilized stable Ag-NPs. 31 The TEM images demonstrate the formation of Ag-NPs at different periods of time. Figure 2 shows typical TEM images and the corresponding particle size distribution of the prepared Ag-NPs at different times.…”

Green synthesis and characterization of gelatin-based and sugar-reduced silver nanoparticles

“…22 The Ag-NPs could dissociate due to heating to form smaller particles stabilized by the amine pendant groups on the gelatin, which leads to the formation of gelatin-stabilized stable Ag-NPs. 23 Figure 2 shows typical TEM images and …”