Photoinduced Amyloid Fibril Degradation for Controlled Cell Patterning

Amyloid-like fibrils are a special class of self-assembling peptides that have emerged as a promising nanomaterial with rich bioactivity for applications such as cell adhesion and growth. Unlike the extracellular matrix, the intrinsically stable amyloid-like fibrils do not respond nor adapt to stimuli of their natural environment. Here, we designed a self-assembling motif (CKFKFQF), in which a photosensitive o-nitrobenzyl linker (PCL) was inserted. This peptide (CKFK-PCL-FQF) assembled into amyloid-like fibrils comparable to the unsubstituted CKFKFQF and revealed a strong response to UV-light. After UV irradiation, the secondary structure of the fibrils, fibril morphology and bioactivity were lost. Thus, coating surfaces with the pre-formed fibrils and exposing them to UV-light through a photomask generated well-defined areas with patterns of intact and destroyed fibrillar morphology. The unexposed, fibril-coated surface areas retained their ability to support cell adhesion in culture, in contrast to the light-exposed regions, where the cell-supportive fibril morphology was destroyed. Consequently, the photoresponsive peptide nanofibrils provide a facile and efficient way of cell patterning, exemplarily demonstrated for A549 cells. This study introduces photoresponsive amyloid-like fibrils as adaptive functional materials to precisely arrange cells on surface.