Novel cyclopeptides for the design of MMP directed delivery devices: a novel smart delivery paradigm.

PURPOSE: Matrix metalloproteinases (MMP) are a family of proteolytic enzymes, the expression of which in a key step of tumor progression has been better defined recently. The studies highlighted the ongoing need for very specific inhibitors, substrates or release devices designed to be selective for one or at least very few MMPs. METHODS: This report deals with the design, synthesis and in vitro evaluation of linear and especially novel cyclic peptidic moieties, embodying MMP cleavable sequences designed to answer these questions. FRET (fluorescence resonance energy transfer) labelling via chromophore-modified amino-acids was used to give access to enzyme kinetics. RESULTS: Evaluation of these peptides showed that cyclisation gives rise to high specificity for certain MMP, suggesting that this approach could provide very specific MMP substrate. Moreover, cyclic structures present a very good plasma stability. CONCLUSIONS: These original derivatives could allow the design of MMP-controlled delivery devices, the specificity of which will be retained in complex biological media and in vivo.