Development of a promising drug delivery for formononetin: Cyclodextrin-modified single-walled carbon nanotubes

The design of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) modified carboxylated single-walled carbon nanotubes (CD-SWCNTs) composition was to improve the biocompatibility and reduce the toxicity of carbon nanotubes as the delivery of anticancer drug formononetin (FMN). According to the result of fourier-transform infrared spectrometry (FTIR), HP-beta-CD was grafted to carboxylated single-walled carbon nanotubes (SWCNTs-COOH) successfully. The entrapment efficiency and loading capacity of the CD-SWCNTs loading with FMN (CD-SWCNTs-FMN) were evaluated by HPLC experiments, which could reach to (88.66 +/- 3.13) % and (8.43 +/- 1.11) % respectively. The samples were characterized by x-ray diffractometry (XRD), differential scanning calorimetry (DSC), laser particle size analysis and scanning electron microscopy (SEM). Moreover, the research on drug release kinetics demonstrated a slow and sustained release. The in vitro cytotoxicity assay revealed that the antitumor activity of CD-SWCNTs-FMN is stronger than that of the free FMN. In conclusion, CD-SWCNTs synthesized in this study were prospective sustained-release and drug-targeting system for antitumor drugs.