Preparation of hollow nanosphere of 5-fluorouracil/layered double hydroxide and its cellular cytotoxicity

We have first prepared the layered double hydroxide (LDH)/carbon nanosphere (CNS) composite by mixing the LDH gel containing methoxide interlayer anion with the CNS template (particle size of 300–700 nm) suspension in methanol at room temperature under ultrasonication. The SEM observation indicates that the CNS core was uniformly covered with the LDH thin film made up by fine plate-like particles to form the composite. Then, the intercalation of anticancer drug, 5-fluorouracil (5-FU), into the LDH interlayer was carried out by the calcination-rehydration reaction and the solid products were analyzed using XRD, FT-IR, SEM, TEM etc. During the calcination process at 500 °C for 3 h, the CNS core was removed by combustion and the LDH shell became the hollow LDH oxide nanosphere. In the following rehydration process at 60 °C for 24 h, this oxide precursor was reconstructed the hollow LDH nanosphere having the surface of coral-like structure (spontaneously formed LDH particles) incorporating 5-FU anion in the interlayer. Finally, the anticancer drug efficacy in vitro of the products was estimated by using the WST-8 assays in HeLa cell lines. As the result, the hollow nanosphere of the 5-FU/LDH performed an improvement of drug efficacy compared to the conventional plate-like particle of the 5-FU/LDH as the reference and the naked 5-FU itself at the same 5-FU concentration.