Functionalized Β-Cyclodextrin for Smart Drug Delivery Application ^†

In recent years, an emphasis has been established on advanced cancer drug delivery, in order to improve the efficiency of the cancer therapy [1]. Cyclodextrin (CD) is a cyclic oligosaccharide formed by 6, 7, or 8 glucose units by α-1,4 glycosidic bonds, which are called α, β, γ-cyclodextrin, respectively [2]. Due to its hollow truncated morphology with a hydrophobic inside and hydrophilic outside, CD has been studied in numerous drug delivery systems [3,4,5]. In the present study, the modification of β-CD with 3-(Aminopropyl)triethoxysilane (APTES) was investigated. For this study we used: β-Cyclodextrin (β-CD) purchased from Fluka, 3-(Aminopropyl) triethoxysilane (APTES) from Sigma Aldrich, NaOH from Roth, dimethylforamide (DMF) from Acros Organics, and acetone from Chimreactiv. Firstly, NaOH, APTES, and DMF were solubilized by magnetic stirring for 1 h at 40 °C. After solubilization, β-CD was added and allowed to react for 2 h, at 40 °C, under magnetic stirring. The functionalized β-CD was precipitated in acetone, and in the end washed and filtered. The sample was dried at room temperature and investigated by NMR. The ¹H NMR was employed to further demonstrate the molecular structure of β-CD. The obtained NMR spectrum of β-CD shows the presence of characteristic proton peaks. The chemical structure of functionalized β-CD was studied, in order to look for possible biomedical applications, such as smart drug delivery systems.