Glycan-Presenting Coacervates Derived from Charged Poly(active esters): Preparation, Phase Behavior, and Lectin...

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Supramolecular Chemistry

Background:

• Complex coacervation is a method for forming liquid droplets from oppositely charged polymers.
• Functionalizing these droplets with specific binding motifs is crucial for targeted applications.
• Carbohydrate-binding proteins and bacteria are important targets in various biological and medical fields.

Purpose of the Study:

• To prepare and characterize glycan-functionalized polyelectrolytes for creating functional liquid condensate droplets.
• To investigate the phase behavior and biomolecular interaction properties of these glycan-presenting droplets.
• To assess the specificity of carbohydrate-mediated binding for capturing proteins and bacteria.

Main Methods:

• Synthesis of polyanions and polycations derived from poly(active ester) for complex coacervation.
• Modular introduction of mannose and galactose oligomers onto the polyelectrolyte chains.
• Formation of liquid condensate droplets via complex coacervation.
• Binding studies using mannose-binding proteins (Concanavalin A) and bacteria (Escherichia coli).

Main Results:

• Glycan functionalization significantly influenced droplet phase separation and critical salt concentration.
• Mannose-functionalized droplets specifically captured mannose-binding proteins and bacteria.
• Non-specific charge-charge interactions were observed with unfunctionalized droplets but were reduced by glycan functionalization.
• Inhibition of mannose interactions or use of non-binding galactose polymers weakened droplet-biomolecule interactions, confirming specificity.

Conclusions:

• A straightforward route to glycan-presenting polyelectrolytes and functional liquid condensate droplets was established.
• These droplets exhibit specific biomolecular interactions mediated by introduced carbohydrates.
• The findings suggest a potential reduction in non-specific binding through glycan functionalization, opening avenues for targeted capture systems.