Novel fluorescein isothiocyanate (FITC) cored PAMAM dendrimers as drug delivery agent

Fluorescent dyes, or fluorophores, enable researchers to visualize specific biological molecules by fluorescence microscopy. Herein, a novel fluorescent FITC-poly(amidoamine) (FITC-PAMAM) dendrimers have been synthesized via divergent approach. The molecular structure of the FITC-PAMAM dendrimers (G-0 to G5) was characterized by 1H NMR, 13C NMR spectroscopy and by FTIR. In order to emphasize the structural efficacy of FITC-PAMAM dendrimer, the drug delivery behavior has been evaluated by using 5-fluorouracil (5-FU) as a model cancer therapy drug. Anti-proliferative activity of FITC-cored PAMAM dendrimers in all generations (G0-G5) with or without 5-FU were analyzed on human gastric carcinoma cells (AGS) by WST-1 cell proliferation assay. Initially, the nontoxic dose of unloaded FITC-PAMAM dendrimers was assessed for further drug loading experiments. Loading of 5-FU into FITC-PAMAM dendrimers, regardless of generation, increased the toxicity of the drug. Besides, 5-FU loaded FITC-PAMAM dendrimers induced a generation-based gradual inhibition of cell proliferation. FITC and phase contrast merged images indicated that FITC-PAMAM dendrimers facilitate the entry of the drug into the cells, in a generation-dependent manner. The FITC- dendrimers may serve as a promising intracellular drug delivery agent for 5-FU by increasing cell uptake into cells and thereby, enhancing antiproliferative activity on AGS cells in a generation-dependent manner.