Fmoc-diphenylalanine-based hydrogels as a potential carrier for drug delivery

Self-assembled hydrogels from 9-fluorenylmethoxycarbonyl-modified diphenylalanine (Fmoc-FF) peptides were evaluated as potential vehicles for drug delivery. During self-assembly of Fmoc-FF, high concentrations of indomethacin (IDM) drugs were shown to be incorporated into the hydrogels. The beta-sheet arrangement of peptides was found to be predominant in Fmoc-FF-IDM hydrogels regardless of the IDM content. The release mechanism for IDM displayed a biphasic profile comprising an initial hydrogel erosion-dominated stage followed by the diffusion-controlled stage. Small amounts of polyamidoamine dendrimer (PAMAM) added to the hydrogel (Fmoc-FF 0.5%-IDM 0.5%-PAMAM 0.03%) resulted in a more prolonged IDM release compared with Fmoc-FF 0.5%-IDM 0.5% hydrogel. Furthermore, these IDM-loaded hydrogels demonstrated excellent thixotropic response and injectability, which make them suitable candidates for use as injectable self-healing matrices for drug delivery.