Thermoresponsive Formation of Dimethyl Cyclodextrin Polypseudorotaxanes and Subsequent One-Pot Synthesis of Polyrotaxanes.

We demonstrated a new strategy for efficient preparation of polypseudorotaxanes (PpRXs) and polyrotaxanes (PRXs) with cyclodextrin derivatives, 2,6-di--methyl-cyclodextrins (DM-CyDs), by utilizing the cloud points of DM-CyDs. DM-α-CyD and DM-β-CyD formed PpRXs with polyethylene glycol (PEG) and polypropylene glycol (PPG) in water at >50 °C and >35 °C, respectively, but did not at room temperature. Meanwhile, randomly methylated β-CyD (RM-β-CyD) and 2,3,6-tri--methyl-β-CyD (TM-β-CyD) did not form PpRX with PPG at higher temperature.

2-Hydroxypropyl-β-Cyclodextrin Acts as a Novel Anticancer Agent.

2-Hydroxypropyl-β-cyclodextrin (HP-β-CyD) is a cyclic oligosaccharide that is widely used as an enabling excipient in pharmaceutical formulations, but also as a cholesterol modifier. HP-β-CyD has recently been approved for the treatment of Niemann-Pick Type C disease, a lysosomal lipid storage disorder, and is used in clinical practice. Since cholesterol accumulation and/or dysregulated cholesterol metabolism has been described in various malignancies, including leukemia, we hypothesized that HP-β-CyD itself might have anticancer effects.