pH-responsive mesoporous silica drug delivery system, its biocompatibility and co-adsorption/co-release of 5-Fluorouracil and Naproxen

A pH-responsive drug delivery system composed of N-(propyl)aniline (N-ANI) modified mesoporous silica nanoparticles as a carrier, and beta-cyclodextrin (beta-CD) as a cap was prepared and investigated. The system was studied for co-adsorption and co-delivery of two different drugs; an anticancer drug 5-fluorouracil (5-FU), and anti-inflammatory agent naproxen (NAP). Detailed adsorption study of the drugs themselves as well as in their mutual mixture was performed. The drug release experiments were realized in simulated body fluid (pH = 7.4) and slightly acidic medium (pH = 5) imitating the pH of tumor affected area. The experiments showed, that at physiological pH 7.4, the prepared drug delivery system released no drug, at slightly acidic medium (pH = 5) the beta-CD caps were loosened, and drugs were released (88.5% and 98.7% for 5-FU and NAP, respectively). To investigate the efficiency of the designed system for the delivery in biological environment, the biocompatibility and cytotoxicity experiments were performed using U87 MG and SKBR3 cancer cells by fluorescence microscopy, flow-cytometry, MTT. apoptotic and CAM assays.