Preparation of Curcumin-Containing α-, ß-, and γ-Cyclodextrin/Polyethyleneglycol-Conjugated Gold Multifunctional Nanoparticles and Their in Vitro Cytotoxic Effects on A549 Cells.

Gold nanoparticles (GNPs) have promising properties such as photothermal effects and could be useful for imaging and as multifunctional nanocarriers for various drugs. In this study, we synthesized polyethyleneglycol (PEG)-grafted GNPs and conjugated them with cyclodextrin (CD) to incorporate curcumin. Curcumin has anticancer effects but its therapeutic application is limited due to poor water solubility. Three types of CDs (α-, ß-, and γ-CDs) were conjugated with PEGylated GNPs and the curcumin-containing CD/PEG-conjugated GNPs (cur-CD-GNPs) were characterized. Transmission electron microscopy and dynamic light scattering results showed that these cur-CD-GNPs have a small gold nanocore (approximately 5 nm) and the average size of the three cur-CD-GNPs was approximately 25-35 nm. Curcumin was efficiently incorporated into the ß-CD solution and the loading efficiency of curcumin in ß-CD-GNPs was the highest of the three types of CD-GNPs prepared. The cytotoxic effect of cur-CD-GNPs was investigated using a human lung cancer cell line. All cur-CD-GNPs exhibited cytotoxic effects comparable to that of curcumin solution and CD-GNPs without curcumin were not cytotoxic. These results suggest that cur-CD-GNPs may be a useful multifunctional nanomedicine, although in vivo investigations are required.

Effective light-triggered contents release from helper lipid-incorporated liposomes co-encapsulating gemcitabine and a water-soluble photosensitizer.

Triggered drug release is a promising strategy for delivering anticancer drugs to cancer cells and tissues. We found that liposomes co-encapsulating calcein (a water-soluble model drug and fluorescence marker) and talaporfin sodium (TPS, a water-soluble photosensitizer) released the drug upon irradiation with a near-infrared (NIR)-laser. The liposomes were composed of phospholipid (DSPC)/helper lipid (DOPE)/cholesterol/PEG-lipid (PEG2000-DSPE) at a molar ratio of 85/10/5/5 and released a large amount of drug (70%<, within 10 min) upon irradiation, but no drug in the absence of NIR-laser irradiation and/or TPS. NIR-laser-triggered drug release was facilitated by the incorporation of DOPE into the liposomes, and the amount of DOPE incorporated affected drug leakage in the absence of NIR-laser-irradiation at 37 °C (body temperature). Drug leakage was tuned by incorporating cholesterol into the liposomes. NIR-laser-triggered drug release from the liposomes was confirmed using the anticancer drug gemcitabine. NIR-laser treatment of liposomes co-encapsulating gemcitabine and TPS provided the maximum cytotoxic effect towards EMT6/P cells. These results suggest that these novel light sensitive liposomes may be useful for drug delivery to cancer cells.