In Vitro Anticancer Activity Of Surface Modified Epothilone Attached Hydroxyapatite

Hydroxyapatite (HA) materials have shown applications in biomedicine due to their high biocompatibility and large surface area. HA as a drug delivery system delivering the drug to the lesion site, controlled release and sustained delivery drugs, reduced the toxicity to normal cells and then improve the utilization of the drug. Epothilone as a novel anticancer drug, its anticancer mechanism is similar to Taxol, but its side-effect is lower and has higher efficacy, its efficacy is 5 to 10 times than Taxol at the same dose. Currently, epothilone B and its derivatives have been used in clinical trials, but there is no report about the nano materials as carrier for epothilione, the research of nano materials modified epothilone has a good conduction to clinical application.The main reasearch aspects are as below:1. HA nanoparticles prepared by coprecipitation methods and then modified with APTES to improve the particles agglometation phenomenon. Then HA nanoparticles were characterized by SEM, TEM, XRD and FITR. The results indicated that, HA nanoparticles crystallized completely and the surface modifier has no effect on the crystalline structure, but the agglometation phenomenon has been improved. Under the TEM, the particle size is around 70-90 nm in lenth and 20 nm in width.2. Conjugation of epothilone to HA nanoparticles, the amount of loaded drug was determined by HPLC. Analysis the effect of solvent, concentration of epothilone and the loading time to drug loading. The maximum carrying capacity was obtained in aceticether and the initial epothilone concentration 1.2 g/L, after 3 hours, HA reached the adorption saturation. And then examined the controlled-release ability of HA-Epothilone, the results indicated that the controlled-release rate of epothilone A and epothilone B is 85% and 96%, respectly.3. Incubation the Hela cells with HA-Epothilone and Epothilone, and then study the effect on the prolifection and apoptosis of Hela cells. The resuls shown that the loaded drugs are both more toxic than the naked drugs. The IC50 of EpoA, HA-EpoA, EpoB and HA-EpoB is 14.3 ng/mL,11.8 ng/mL,10.2 ng/mL and 8.7 ng/mL, respectively. The apoptosis of Hela cells was analyzed by Annexin V-FITC/PI double staining method, the apoptosis rate of Hela cells were higher when treated with nanomaterial loaded drugs than naked drugs at the same dose. Under the TEM we found that the nuclear membrane and the fiber fluff of cell membrane was disappeared, and the nucleolus was cleavage. And we also observed many bumps, at last it drew off, became apoptotic bodies.