Search

A pH-responsive supramolecular nanoparticles was constructed through the electrostatic interaction from anionic sulfobutyl ether-[beta]-cyclodextrin ([SBE.sub.7]-[beta]-CD) and two positively charged chitosan (CS-75% and CS-95%). The prepared nanoparticles were characterized by UV-vis absorption spectra, x-ray diffraction, dynamic light scattering, transmission electron microscopy, and zeta potential. It was found that the CS/[SBE.sub.7]-[beta]-CD nanoparticles can be disassembly by increasing pH value and reassembled by reducing to the original pH value. To explore the potential of the obtained nanoparticles as a drug delivery vehicle, a negatively charged anticardio cerebrovascular drug sodium ferulate (SF) was loaded. The result indicated that the SF could be efficiently encapsulated in its nanoparticle nucleus under simulated gastric conditions with lower pH (pH 2.0), while effective release is triggered in a simulated intestinal environment with higher pH (pH 8.5). The assembly/disassembly behavior and drug loading/release property make CS/[SBE.sub.7]-[beta]-CD nanoparticles promising candidates for pH stimulation responsive drug delivery system, which has a broad application prospect in the treatment of cardiovascular and cerebrovascular diseases, diabetes and other chronic diseases. KEYWORDS chitosan, pH-controlled release, sodium ferulate, sulfobutyl ether-[beta]- cyclodextrin, supramolecular nanoparticles, 1 | INTRODUCTION In the past few decades, controllable supramolecular nanoassembly constructed by several kinds of weak noncovalent interactions [1,2] have attracted considerable research interest because of their ease of [...]

20(S)-protopanaxatriol (PPT) is a kind of tetracyclic triterpenoid, which is found in the roots of ginseng. It is well known as a potential herbal medicine or healthcare product. However, given its poor water solubility, its application has been limited. In this study, we successfully synthesized a novel mono-[6-(N,N-bis(3-aminopropyl)ethylenediamine)-6-deoxy]-β-cyclodextrin. We prepared inclusion complexes of PPT with three polyamine-modified β-cyclodextrins (CDs) (H1, H2, and H3) of different lengths by the coprecipitation method, aiming at enhancing the aqueous solubility of PPT. The host–guest inclusion complexes of H1, H2, and H3 with PPT were characterized via 1H NMR, XRD, FT-IR spectra, and SEM technology, and the inclusion modes were analyzed by 2D ROESY. The stability constant (Ks), inclusion ratios, and solubility of H1, H2, and H3 with PPT were determined via the phase solubility method. The stability constants (K1:1) were found to be 182.6, 94.2, and 524.4 M−1 for H1/PPT, H2/PPT, and H3/PPT inclusion complexes, with AL-, AN-, and BS-type curves, respectively. That is, when the stoichiometric ratio was 1:1, H3 (with longest-length chain) displayed the strongest binding ability with PPT. The host–guest size/shape-fit relationship and hydrogen bond interaction play a role in improving the stability of H1/PPT, H2/PPT, and H3/PPT inclusion complexes. Through complexation with H1, H2, and H3, the apparent solubility of PPT was obviously increased from the initial value of 0.062 mg/L to 5.1, 3.0, and 7.5 g/L, respectively. Among the three CDs, the solubilization effect of PPT with H3 was the best. Furthermore, H1/PPT, H2/PPT, and H3/PPT inclusion complexes exhibited some activity in inhibiting LPS-induced nitric oxide (NO) generation in macrophages. This satisfactory aqueous solubility and higher stability of H1/PPT, H2/PPT, and H3/PPT inclusion complexes should be possibly useful for its utilization as a herbal medicine and healthcare product. [ABSTRACT FROM AUTHOR]