Preparation of novel dual-site drug delivery system based on hydroxypropyl methyl cyclodextrin.

An amphipathic copolymer of poly(polyethylene glycol-b-polycaprolactone-co-hydroxypropyl methyl cyclodextrin) [poly(mPEG-b-PCL-co-HPCD)] was synthesized via the free radical polymerization. The copolymer was used to prepare novel nanoparticles (NPs) by a solvent evaporation method. Curcumin (CUR) was selected as a model drug and loaded in the both sites of inner NPs and the cavities of HPCD. 1 H nuclear magnetic resonance (1 H NMR) study was carried out to confirm the synthesis of poly(mPEG-b-PCL-co-HPCD). The morphology and particle size distribution of the cargo-free NPs were monitored with transmission electron microscopy (TEM) and Malvern particle sizer. The distribution state of CUR in the CUR-loaded NPs was studied with differential scanning calorimetry (DSC) and X-ray diffraction (XRD) methods. The 1 H NMR spectrum demonstrated the successful preparation of poly(mPEG-b-PCL-co-HPCD) copolymer. TEM photograph illustrated that the cargo-free NPs had a spherical morphology with an average diameter of 229±32.8nm. The cargo-free NPs had a low critical micelle concentration of 2.9×10-2 mg/mL. The HepG2 cells incubated with 1.0mg/mL NPs suspension showed high cell viability. The drug release profile showed that the medicated NPs could continuously release CUR for 24h. Therefore, the poly(mPEG-b-PCL-co-HPCD) NPs had a potential application on the drug delivery.