Nanostructured lipid carriers enhance the bioavailability and brain cancer inhibitory efficacy of curcumin both in vitro and in vivo.

Brain cancer is a kind of tough carcinoma because the blood-brain barrier (BBB) remains a formidable obstacle in medicine. Curcumin (Cur) was determined to have anticancer potency on several kinds of carcinoma. However, its medical application was limited because of its poor bioavailability, unsatisfying dispersity and rapid metabolism in vivo. In this study, Cur was delivered by nanostructured lipid carriers (NLCs) for brain cancer treatment. The physiochemical characters of NLC-Cur were detected by using high-performance liquid chromatography, Transmission electron microscopy and photon correlation spectrum analyses. The cellular uptake and the anticancer efficiency were determined both in vitro and in vivo by flow cytometry detection, MTT assay, AO/EB, Annexin-V/PI, DCFDA and tumor-bearing mice. NLC-Cur was synthesized by using sol-gel method and with the size around 100 nm. After loaded in NLC, the IC50 of NLC-Cur was 20 µg/mL, only one-fourth of the plain drug. The plasmid concentration of Cur was highly increased (6.4-folds) in mice via intraperitoneally after loaded with NLC. Furthermore, NLC-Cur enhanced the targeting effect of Cur to brain and tumor, which finally increased the inhibition efficiency of Cur from 19.5% to 82.3%. The FITC analysis confirmed that the inhibition effect mostly came from apoptosis, but not necrosis. The time depending cellular uptake, reactive oxygen species production, markedly increased bio-availability and tumor targeting effect played an important role in the efficacy of NLC-Cur. Our work indicated the medical application of NLC-Cur on brain cancer treatment, and also provided a novel method for new anticancer agents' development.