Side-chain-induced changes in aminated chitosan: Insights from molecular dynamics simulations

Area of Science:

• Polymer Science
• Computational Chemistry
• Biomaterials Science

Background:

• Chitosan is a versatile functional polymer with applications in biomedicine, agriculture, and water treatment.
• Derivatization of chitosan allows for tailored functionality, such as biomolecule immobilization.
• Previous experimental studies on functionalized chitosan lacked molecular-level explanations for observed properties.

Purpose of the Study:

• To develop a computational protocol for simulating functionalized chitosan polymers.
• To analyze the conformational states, intramolecular interactions, and water binding of aminated chitosan derivatives.
• To elucidate the molecular mechanisms behind the behavior of functionalized chitosan.

Main Methods:

• Molecular dynamics simulations of three aminated chitosan polymers with varying side chain modifications.
• Advanced analysis of polymer conformational states, including dihedral angles and intramolecular forces.
• Investigation of polymer-water interactions and hydrogen bonding patterns.

Main Results:

• Side chain modifications and resulting hydrogen bonds significantly influence chitosan backbone conformation and water interactions.
• The chemical composition of functionalized chitosans dictates their tendency to collapse.
• Protonation of amino groups near the polymer backbone reduces polymer collapse, enhancing specific water binding.

Conclusions:

• Computational simulations provide molecular insights into functionalized chitosan behavior.
• Hydrogen bonding and amino group protonation are critical factors controlling chitosan polymer structure and hydration.
• Understanding these molecular interactions is essential for designing advanced chitosan-based materials.