Supramolecular Peptoid Structure Strengthens Complexation with Polyacrylic Acid Microgels

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials

Background:

• Developing self-defensive surfaces that resist bacterial colonization is crucial for preventing infections.
• Polyanionic microgels offer a versatile platform for loading and releasing active agents.
• Cationic antimicrobials are essential components for antimicrobial surface technologies.

Purpose of the Study:

• To investigate the complexation strength between poly(acrylic acid) (PAA) microgels and various cationic peptoid structures.
• To evaluate the stability of these complexes under varying ionic strengths, mimicking physiological conditions.
• To understand how peptoid supramolecular structure influences antimicrobial release and surface defense.

Main Methods:

• Complexation of PAA microgels with a series of cationic peptoids (monomer to tetramer).
• Monitoring changes in microgel diameter with increasing sodium ion ([Na+]) concentration to assess release.
• Analyzing the relationship between peptoid supramolecular structure and resistance to salting out.

Main Results:

• A monomeric peptoid was released from PAA microgels at low ionic strengths, below physiological levels.
• Higher-order peptoid structures (dimer, trimer, tetramer) exhibited significantly greater resistance to release with increasing ionic strength.
• The stability against salt-induced release correlated with the degree of peptoid supramolecular assembly.

Conclusions:

• The supramolecular structure of cationic peptoids plays a critical role in their stable complexation with PAA microgels.
• Multimeric peptoid structures offer enhanced stability, leading to more robust self-defensive surfaces.
• These findings provide insights into designing advanced antimicrobial surfaces with tunable release properties.