Exploring the Interactions Between Methyl Methacrylate Polymers and the Bacterial Outer Membrane via Coarse-Grained...

Area of Science:

• Biomaterials Science
• Computational Biology
• Surface Chemistry

Background:

• Polymer brush coatings are crucial for preventing bacterial adhesion and biofilm formation on medical devices.
• A molecular-level understanding of polymer-membrane interactions is needed to optimize these coatings.
• Existing knowledge gaps hinder the rational design of effective antibacterial surface technologies.

Purpose of the Study:

• To investigate the molecular mechanisms of polymer interaction with bacterial membranes using advanced simulation techniques.
• To compare the translocation behavior of four different polymer chemistries (cationic, zwitterionic, anionic) through a bacterial outer membrane model.
• To elucidate the role of polymer charge and structure in bacterial adhesion and membrane permeation.

Main Methods:

• Coarse-grained steered molecular dynamics simulations.
• Umbrella sampling simulations to determine free-energy landscapes.
• Modeling the outer membrane of *Escherichia coli* and its interaction with methyl methacrylate-derived polymers.

Main Results:

• A four-step translocation process (approach, adhesion, permeation, internalization) was identified with distinct thermodynamic and kinetic features.
• Cationic polymers (pDMAEMA, pMETAC) showed strong adhesion to the bacterial outer membrane, particularly to LPS saccharide domains, driven by electrostatic interactions.
• Anionic and zwitterionic polymers exhibited less favorable adhesion, correlating with their known antifouling properties.

Conclusions:

• Computational simulations provide a detailed molecular understanding of polymer-bacterial membrane interactions.
• Electrostatic interactions significantly influence polymer adhesion to bacterial outer membranes.
• These findings advance the design principles for novel antifouling and antibacterial polymer coatings for medical applications.