Modeling Plasma-Induced Modifications in Alginate Biopolymers at the Atomic Scale

This study investigates the impact of reactive oxygen species produced by nonthermal plasma on biopolymers using computer simulations. Specifically, reactive molecular dynamics simulations are employed to study the interaction between oxygen atomsa key short-lived component generated during direct plasma treatmentand the alginate molecule, which serves as the model system in our analysis. The simulations reveal that oxygen atom impact leads to significant structural changes, including oxygen addition (44.5%), glycosidic bond cleavage (13.5%), ring opening (31%), and organic peroxide formation (25%) (these events are not mutually exclusive, and therefore, the percentages do not sum directly to 100%). Additionally, the oxidation process results in carboxyl group reduction and CO₂ detachment (13%), potentially altering the cross-linking properties of alginate. Our model results align with existing experiment findings and provide deep insight into the interaction between alginate and plasma-generated reactive species. This is fundamental for the use of biopolymers, particularly those capable of forming hydrogels, combined with plasma, for biomedical applications.