Competitive coordination assembly of light-degradable gold nanocluster-intercalated metal organic frameworks for photoresponsive drug release.

On-demand controlled drug release holds great promise for cancer therapy. Light-degradable nanocarriers have gained increasing attention for designing controllable drug delivery systems owing to their spatiotemporally controllable properties. Herein, a highly luminescent and light-degradable nanocarrier is constructed by intercalating glutathione-capped gold nanoclusters (AuNCs) into zeolitic imidazolate framework-8 (ZIF-8) via competitive coordination assembly, named AuNC@ZIF-8, for light-triggered drug release. Glutathione-capped AuNCs and 2-methylimidazole (MIm) competitively coordinated with Zn2+ to form AuNC@ZIF-8 using a one step process in an aqueous solution. Specifically, the obtained AuNC@ZIF-8 has a high quantum yield of 52.96% and displays a distinctive property of photolysis. Competitive coordination interactions within AuNC@ZIF-8 were evidenced by X-ray diffraction and X-ray photoelectron spectroscopy, in which Zn2+ strongly coordinated with the N of MIm and weakly coordinated with the carboxyl/amino groups in the glutathione of AuNCs. Under light irradiation, the Au-S bond in AuNCs breaks, enhancing the coordination ability between carboxyl/amino groups and Zn2+. This collapses the crystal structure of AuNC@ZIF-8 and causes subsequent fluorescence quenching. Additionally, AuNC@ZIF-8 is successfully employed as a luminescent nanocarrier of anticancer drugs to form drug-AuNC@ZIF-8, in which three typical anticancer drugs are selected due to different coordination interactions. The obtained smart drug-AuNC@ZIF-8 can be effectively internalized into HeLa cells and degraded in response to blue light, with negligible dark cytotoxicity and high light cytotoxicity. This study highlights the crucial role of competitive coordination interactions in synthesizing functional materials with fluorescence efficiency and photolytic properties.

Curcumol: a review of its pharmacology, pharmacokinetics, drug delivery systems, structure-activity relationships, and potential applications.

Curcumol (Cur), a guaiane-type sesquiterpenoid hemiketal, is an important and representative bioactive component extracted from the essential oil of the rhizomes of Curcumae rhizoma which is also known as "Ezhu" in traditional Chinese medicine. Recently, Cur has received considerable attention from the research community due to its favorable pharmacological activities, including anti-cancer, hepatoprotective, anti-inflammatory, anti-viral, anti-convulsant, and other activities, and has also exerted therapeutic effect on various cancers, liver diseases, inflammatory diseases, and infectious diseases. Pharmacokinetic studies have shown that Cur is rapidly distributed in almost all organs of rats after intragastric administration with high concentrations in the small intestine and colon. Several studies focusing on structure-activity relationship (SAR) of Cur have shown that some Cur derivatives, chemically modified at C-8 or C-14, exhibited more potent anti-cancer activity and lower toxicity than Cur itself. This review aims to comprehensively summarize the latest advances in the pharmacological and pharmacokinetic properties of Cur in the last decade with a focus on its anti-cancer and hepatoprotective potentials, as well as the research progress in drug delivery system and potential applications of Cur to date, to provide researchers with the latest information, to highlighted the limitations of relevant research at the current stage and the aspects that should be addressed in future research. Our results indicate that Cur and its derivatives could serve as potential novel agents for the treatment of a variety of diseases, particularly cancer and liver diseases.