Photoinduced Amyloid Fibril Degradation for Controlled Cell Patterning

Amyloid‐like fibrils are a special class of self‐assembling peptides that emerge 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, a self‐assembling motif (CKFKFQF), in which a photosensitive o‐nitrobenzyl linker (PCL) is inserted, is designed. This peptide (CKFK‐PCL‐FQF) assembles into amyloid‐like fibrils comparable to the unsubstituted CKFKFQF and reveals a strong response to UV‐light. After UV irradiation, the secondary structure of the fibrils, fibril morphology, and bioactivity are lost. Thus, coating surfaces with the pre‐formed fibrils and exposing them to UV‐light through a photomask generate well‐defined areas with patterns of intact and destroyed fibrillar morphology. The unexposed, fibril‐coated surface areas retain their ability to support cell adhesion in culture, in contrast to the light‐exposed regions, where the cell‐supportive fibril morphology is destroyed. Consequently, the photoresponsive peptide nanofibrils provide a facile and efficient way of cell patterning, exemplarily demonstrated for A549, Chinese Hamster Ovary, and Raw Dual type cells. This study introduces photoresponsive amyloid‐like fibrils as adaptive functional materials to precisely arrange cells on surfaces. Photoreactive self‐assembling peptide sequences can form cell‐adhesive fibrillar structures. The fibril morphology can locally be destroyed through an external trigger, that is UV‐light irradiation, resulting in immediate loss of β‐sheet structures, nanofibril morphology, and cell adhesiveness of the peptides. Thus, coatings of the photocleavable self‐assembling fibrils can be applied for controlled cell attachment via a photopatterning strategy.