In-situ, light-guided axon growth on biomaterials via photoactivatable Laminin peptidomimetic IK(HANBP)VAV.

The ability to guide the growth of neurites is relevant for reconstructing neural networks and for nerve tissue regeneration. Here, a biofunctional hydrogel that allows light-based directional control of axon growth in-situ is presented. The gel is covalently modified with a photoactivatable derivative of the short laminin peptidomimetic IKVAV. This adhesive peptide contains the photoremovable group 2-(4'-amino-4-nitro-[1,1'-biphenyl]-3-yl)propan-1-ol (HANBP) on the Lys rest that inhibits its activity. The modified peptide is highly soluble in water and can be simply conjugated to -COOH containing hydrogels via its terminal -NH2 group. Light exposure allows presentation of the IKVAV adhesive motif on a soft hydrogel at desired concentration, and at defined position and time point. The photoactivated gel supports neurite outgrowth in embryonic neural progenitor cells (eNPCs) culture and allows site-selective guidance of neurites extension. In-situ exposure of cell cultures using a scanning laser allows outgrowth of neurites in desired pathways.