Extended Data Fig. 5: Control of particle size and shape.
From: Adaptive peptide dispersions enable drying-induced biomolecule encapsulation
a. The effect of temperature on the size of porous peptide particles formed by tripeptides, and KWY was shown. For Imaris 3D Rendering, traceable blue fluorescence signals excited by 405 nm were captured by confocal coupling with bright-field imaging. Spot rendering was employed to analyze the diameter of the particle; b. while the actual shape was revealed by surface rendering in high transparency mode; c-d. The Sphericity of approximately 200 particles at 40 °C and 1000 particles at 80 °C were profiled, indicating that at high temperature, droplets are not given sufficient time to accumulate at the interface and consequently remain rounded. In violin plot, the horizontal lines display the median as well as 25th and 75th percentiles.); e. Buffer concentration regulates the dynamics of tripeptide particle formation. 20 mM WKY peptide was dissolved in phosphate buffer at the concentrations of 25, 50, 100, 250, 500, 1000 mM. Imaris 3D rendering of the dried particles at each concentration demonstrated reduction in particle size and increase in homogeneity with the increase of salt concentration. Color scale bar represents size, scale bar = 10 µm; f. The peptide solution was degassed followed by evaporation assay, and the example of WKY is shown. Time-lapse confocal imaging of bright field and 405 nm excitation demonstrated reduction in particle size. Scale bar = 50 µm; g. Further AFM analysis of WKY shows fewer and smaller pores in the dried particles of the degassed sample.
