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.