Interfacial force-driven pattern formation during drying of Aβ (25-35) fibrils.

Area of Science:

• Biomedical Engineering
• Materials Science
• Neuroscience

Background:

• Pattern formation during biofluid evaporation has biomedical applications for disease identification.
• Amyloid-beta (25-35) peptide is a toxic fragment associated with Alzheimer's disease.

Purpose of the Study:

• To investigate the drying patterns of amyloid-beta (25-35) fibrils on substrates with varying wettability.
• To understand how substrate wettability influences fibril self-assembly and pattern formation during evaporation.

Main Methods:

• Drying experiments using amyloid-beta (25-35) fibrils as a model solute.
• Visualization of fibril patterns using fluorescence microscopy and transmission electron microscopy.
• Controlled manipulation of evaporation rates to study drag and capillary forces.

Main Results:

• Unique drying patterns of amyloid-beta (25-35) fibrils were observed, dependent on substrate wettability.
• Pattern formation was linked to changes in the self-pinning mechanism, sometimes resembling the coffee ring effect.
• Altering evaporation rates affected the balance of forces, influencing fibril patterning.

Conclusions:

• Substrate wettability significantly impacts amyloid-beta (25-35) fibril self-assembly and pattern formation during drying.
• The study provides insights into the physical mechanisms governing amyloid fibril deposition, relevant to Alzheimer's disease.
• Controlled evaporation offers a method to probe and potentially manipulate amyloid fibril patterning for diagnostic or therapeutic strategies.