Synthesis of cationic β-cyclodextrin functionalized silver nanoparticles and their drug-loading applications

Abstract

Silver nanoparticles have attracted great attention owing to their distinct physicochemical properties, which inspire the development of their synthesis methodology and their potential biomedical applications. In this study, a novel cationic β-cyclodextrin (C-β-CD) containing a quaternary ammonium group and amino group was applied as a reducing agent as well as a stabilizing agent to prepare C-β-CD modified silver nanoparticles (CβCD-AgNPs). Besides, based on the inclusion complexation between drug molecules and C-β-CD, the application of CβCD-AgNPs in drug loading was explored by the inclusion interaction with thymol. The formation of AgNPs was confirmed by ultraviolet-visible spectroscopy (UV-vis) and X-ray diffraction spectroscopy (XRD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the prepared CβCD-AgNPs were well dispersed with particle sizes between 3–13 nm, and the zeta potential measurement result suggested that the C-β-CD played a role in preventing their aggregation in solution. ¹H Nuclear magnetic resonance spectroscopy (¹H-NMR) and Fourier transform infrared spectroscopy (FT-IR) revealed the encapsulation and reduction of AgNPs by C-β-CD. The drug-loading action of CβCD-AgNPs was demonstrated by UV-vis and headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS), and the results of TEM images showed the size increase of nanoparticles after drug loading.