Self‐assembling amyloid‐like peptides as exogenous second harmonic probes for bioimaging applications

다국어 초록 (Multilingual Abstract)

Amyloid‐like peptides are an ideal model for the mechanistic study of amyloidosis, which may lead to many human diseases, such as Alzheimer disease. This study reports a strong second harmonic generation (SHG) effect of amyloid‐like peptides, having a signal equivalent to or even higher than those of endogenous collagen fibers. Several amyloid‐like peptides (both synthetic and natural) were examined under SHG microscopy and shown they are SHG‐active. These peptides can also be observed inside cells (in vitro). This interesting property can make these amyloid‐like peptides second harmonic probes for bioimaging applications. Furthermore, SHG microscopy can provide a simple and label‐free approach to detect amyloidosis. Lattice corneal dystrophy was chosen as a model disease of amyloidosis. Morphological difference between normal and diseased human corneal biopsy samples can be easily recognized, proving that SHG can be a useful tool for disease diagnosis.
Ultrashort peptides undergo self‐assembling and form nanofibers. In this schematic diagram, each blue triangle together with an orange circle represents an ultrashort peptide. The orange circle represents a hydrophilic headgroup and the blue triangle represents a hydrophobic tail with an increasing hydrophobicity. The ultrashort peptide nanofibers are able to generate second harmonic light. When excited at 810 nm, ultrashort peptide nanofibers emitted a sharp peak at 405 nm.