No abstract

The best strategy in the development of topical drug delivery systems may be to facilitate the permeation of drugs without any harmful effects, while staying on the skin surface and maintaining stability of the system. Nanodiamonds (NDs) play a key role with their excellent physicochemical properties, including high biocompatibility, physical adsorption, reactive oxygen species (ROS) scavenging capability, and photostabilizing activity. Z -average sizes of carboxylated ND (ND–COOH) agglutinate decreased significantly as the pH increased. Fluorescein-conjugated ND was observed only on the stratum corneum, and no sample diffused into the dermal layer even after 48 hours. Moreover, ND–COOH and ND–COOH/eugenol complex did not show significant toxic effects on murine macrophage cells. ND improved in vitro skin permeation >50% acting as a “drug reservoir” to maintain a high drug concentration in the donor chamber, which was supported by quartz crystal microbalance results. Moreover, ND–COOH could adsorb a drug amount equivalent to 80% of its own weight. A photostability study showed that ND–COOH increased the photostability ~47% with regard to rate constant of the eugenol itself. A significant decrease in ROS was observed in the ND–COOH and ND–COOH/eugenol complex compared with the negative control during intracellular ROS assay. Moreover, ROS and cupric reducing antioxidant capacity evaluation showed that ND–COOH had synergistic effects of antioxidation with eugenol. Therefore, ND–COOH could be used as an excellent topical drug delivery system with improved permeability, higher stability, and minimized safety issue.

Novel artemisinin-glycolipid hybrids were directly synthesized from 12b b (C-C)-type deoxoartemisinin and glycolipid and exhibited exceptional in vitro anticancer activity, particularly against the oral carcinoma cancer cell lines, respectively. The artemisinin-glycolipid hybrids, with effective concentrations under 20 m mM, demonstrated better anticancer activity than either artemisinin or glycolipid alone and showed five times more anti-oral cancer activity than either cisplatin or paclitaxel.

Daumone, a dauer-inducing pheromone and a series of lipid derivatives were synthesized from daumone to investigate structure-activity trends. Lipid derivatives demonstrated potent in vivo antiangiogenic activity on the chorioallantoic membrane, which exceeded that of fumagillin and thalidomide as reference agents. Among the 11 synthetic compounds tested, new derivatives 3, 11 and 13 showed the most potent antiangiogenic activity, which was twice that of fumagillin and thalidomide, replacing these as the most potent known antiangiogenic agents.

The practical synthesis and anticancer activity of novel deoxoartemisinin-glycolipid hybrids, which incorporate two drugs into a single molecule and can impact multiple targets simultaneously are presented. These hybrids exhibited potent in vitro anticancer activity against several human cancer cell lines. The deoxoartemisinin-glycolipid hybrids generally demonstrated better anticancer activity than either artemisinin or daumone alone and cisplatin.