Eu3+-doped MgAl LDH with fluorescence as carrier for 5-fluorouracil: intercalation and release

摘要

The drug delivery systems with fluorescent labeling have been developed as a promising strategy for marking delivery and release of the drugs. For this purpose, a drug delivery system based on Eu3+-doped MgAl-layered double hydroxide (Eu3+-doped MgAl-LDH), as a carrier of 5-fluorouracil, was designed for marking the delivery and release of 5-fluorouracil. Various characterizations, including X-ray diffraction patterns, scanning electron microscopy equipped with energy-dispersive spectroscopy (SEM-EDS), infrared spectroscopy, ultraviolet absorption spectroscopy, and photoluminescent spectroscopy, have been performed. It was found that the 5-fluorouracil (5-Fu) was successfully intercalated (or loaded) into the Eu3+-doped MgAl-LDH and the 5-Fu loaded on the carrier was about 23.2. Then, the Eu3+-doped MgAl-LDH loaded with 5-Fu was dispersed in potassium phosphate-based buffer solution (pH = 7.4) to release of 5-Fu. Results revealed that the cumulative concentration (C) of the released 5-Fu versus the release time (t) fitted with the logistic model and conformed to the equation: C = a + (b - a)/1 + (t/t(0))(3). It took 300 min for the drug carrier to release of the 5-Fu completely. Fluorescent study suggested that the red emissions at 595 and 620 nm of the Eu3+-doped MgAl-LDH greatly decreased after the 5-Fu loaded into the Eu3+-doped MgAl-LDH, and then recovered and even became stronger after the release of 5-Fu from the carrier. This fluorescent change may be a favorable signal for "detecting" the delivery and release of 5-Fu. Thus, the present Eu3+-doped MgAl-LDH may be a promising candidate for drug delivery system with fluorescent labeling.