Peptide-Assisted Cellular Migration Along eNgineered surfaces

The scientific idea of the PACMAN project is to engineer nanostructured surfaces driving bidirectional cellular displacements from an initial (“home”
station) to a final (“work” station) position by remotely-controllable instructions chemically imprinted on a surface-confined gradient, mimicking an haptotatic process. Thus, it is envisaged to prepare supramolecularly- organized dynamic gradients exposing a motogenic peptide fragment (Isoleucine-Glycine-Aspartic acid-Glutamine, IGDQ) that, upon an external stimulus, undergoes directional inversion. Exploiting the different stability of duplexes formed by DNA and peptide nucleic acids (PNA) and the possibility of introducing photo-cleavable protecting groups, it is planned to link the IGDQ to a PNA strand that at the first place undergoes hybridization with only one of the two surface-confined nucleic acids strands patterned on Au through S-Au bonds following two opposite gradients (i.e., tracing the path from “home” to “work”). Upon light excitation, it is envisaged to trigger the affinity of the motogenic IGDQ-PNA strand by changing their nucleobase matching sequence caused by the removal of a photo-cleavable protecting group, thus favoring the formation of the most stable duplex in the opposite direction (i.e., tracing the path back, from “work” to “home”). By this way it will be possible to evaluate, on a time lapse of few days, the bidirectional cellular migration of model cell lines and the exploitation of such displacement to accomplish a defined task, such as uptake of an extracellular body.