Host-guest inclusion system of rhein with polyamine-modified ß-cyclodextrins: characterization and cytotoxicity.

We report the preparation of inclusion complexes between rhein and four polyamine-modified ß-cyclodextrins, namely amino-ß-cyclodextrins (NH2-ßCD), ethylenediamine-ß-cyclodextrins (EN-ßCD), diethylenetriamine-ß-cyclodextrins (DETA-ßCD) and triethylenetetramine-ß-cyclodextrins (TETA-ßCD) using suspension method. The solution and solid state forms of the inclusion complexes of rhein with polyamine-ß-cyclodextrins were characterized by multiple techniques. Additionally, saturated solution and MTT methods were implemented to assess the water solubilization and in vitro cytotoxicity of the inclusion complexes, respectively. The results suggested that rhein was encapsulated within the CD cavity to form a 1:1 host-guest inclusion complex. Notably, a significant enhancement of the water solubility and in vitro cytotoxicity of rhein was found in the form of inclusion complex with polyamine-ß-cyclodextrin.

Folic-Acid-Targeted Self-Assembling Supramolecular Carrier for Gene Delivery.

A targeting gene carrier for cancer-specific delivery was successfully developed through a "multilayer bricks-mortar" strategy. The gene carrier was composed of adamantane-functionalized folic acid (FA-AD), an adamantane-functionalized poly(ethylene glycol) derivative (PEG-AD), and ß-cyclodextrin-grafted low-molecular-weight branched polyethylenimine (PEI-CD). Carriers produced by two different self-assembly schemes, involving either precomplexation of the PEI-CD with the FA-AD and PEG-AD before pDNA condensation (Method A) or pDNA condensation with the PEI-CD prior to addition of the FA-AD and PEG-AD to engage host-guest complexation (Method B) were investigated for their ability to compact pDNA into nanoparticles. Cell viability studies show that the material produced by the Method A assembly scheme has lower cytotoxicity than branched PEI 25 kDa (PEI-25KD) and that the transfection efficiency is maintained. These findings suggest that the gene carrier, based on multivalent host-guest interactions, could be an effective, targeted, and low-toxicity carrier for delivering nucleic acid to target cells.