Spread Layers of Lysozyme Microgel at Liquid Surface

Area of Science:

• Colloid and Surface Science
• Materials Science
• Biophysics

Background:

• Protein microgels are utilized in various applications, but their interfacial behavior is not fully understood.
• Understanding the interfacial properties of lysozyme (LYS) microgel layers is crucial for optimizing their performance.

Purpose of the Study:

• To investigate and compare the interfacial properties of lysozyme (LYS) microgel layers with those of beta-lactoglobulin (BLG) microgel layers.
• To elucidate the aggregation and spreading behavior of LYS microgel particles at liquid interfaces.

Main Methods:

• Surface dilational rheology
• Infrared reflection-absorption spectroscopy
• Brewster angle microscopy
• Atomic force microscopy
• Scanning electron microscopy

Main Results:

• LYS microgel layers exhibit significantly different properties compared to BLG microgel layers.
• Unlike BLG, LYS microgel particles form three-dimensional clusters during spreading and do not form a monolayer.
• The dynamic surface elasticity of LYS microgel layers remains low and does not show characteristic layer collapse features observed in BLG layers.
• LYS spreading results in uneven distribution with large empty surface regions and concentrated patches.

Conclusions:

• LYS microgel particles aggregate into clusters during spreading, limiting their ability to form uniform layers at interfaces.
• The interfacial behavior of LYS microgels differs markedly from BLG, impacting their potential applications.
• The findings highlight the importance of particle morphology and aggregation in determining protein microgel interfacial properties.