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Plasma-induced destruction of bacterial cell wall components: A reactive molecular dynamics simulation

Evidence and attribution

Authority of statements

Prose below summarizes the publication identified by doi, title, and pdf_path. For species-specific bond-breaking pathways and rates, use the article and SI.

Summary

Reactive molecular dynamics (ReaxFF) probes how plasma-relevant species (OH, O, O₃, H₂O₂, plus O₂ and H₂O) interact with a Staphylococcus aureus peptidoglycan model. The paper reports that OH, O, O₃, and H₂O₂ can rupture structurally important C–O, C–N, and C–C bonds, whereas H₂O and O₂ do not break those backbone bonds in the same sense; mechanisms and effectiveness are species-dependent (abstract and computational details in papers/Yusupov_Plasma_BacterialWall_JPCC_2013.pdf).

Methods

Force-field training: N/A — the study applies an existing ReaxFF parameter set (C/H/O/N glycine/water parameters of Rahaman et al. cited in the article), not a new fit.

Static QM / DFT-only: N/A — central results are ReaxFF trajectories, not a standalone DFT benchmark paper.

1 — MD application (atomistic dynamics). Engine / code: Reactive MD with ReaxFF as described in the J. Phys. Chem. C article; the integrator package (e.g. LAMMPS) is N/A — not named on pages 1–2 of normalized/extracts/2013yusupov-venue-jp3128516_p1-2.txt (confirm in the PDF/SI if reproducing runs). System size and composition: S. aureus peptidoglycan in a simulation box of roughly 75 × 88 × 51 Å without solvent bulk beyond the projectile species. Boundaries / periodicity: Nonperiodic cell (no PBC per computational details). Ensemble: impact trajectories after 300 K equilibration of the PG; the article does not spell out a named thermostat for the 300 ps impact segments on the excerpted pages—N/A — thermostat family for production impacts not restated in the p1–2 extract (see full text). Timestep: 0.1 fs. Duration / stages: 300 ps per trajectory; 50 runs per impinging species, each starting with 10 incident particles placed ≥10 Å apart with room-temperature-sampled speeds and random directions. Thermostat: N/A — beyond pre-impact 300 K PG equilibration, explicit damping constants for the impact segment are not in the p1–2 extract. Barostat: N/A — not an NPT bulk simulation. Temperature: 300 K PG equilibration; incident speeds sampled for room temperature. Pressure: N/A — no hydrostatic pressure control described for this open-boundary impact setup. Electric field: N/A — not used. Replica / enhanced sampling: N/A — not used.

Findings

  • H₂O and O₂ impacts do not break the C–O / C–N / C–C “backbone” bonds flagged as structurally important; molecules mainly adsorb via H-bonding to PG.
  • OH, O, O₃, and H₂O₂ can rupture those key bonds, but pathways differ strongly with species (hydrogen abstraction, direct oxidation, etc., as detailed per species in the Results).
  • Because mechanisms and bond targets differ, the relative effectiveness of wall disruption is species-dependent, matching the abstract’s emphasis on nonuniform plasma-oxidant reactivity.
  • Compared to controls: H₂O and O₂ are summarized as non-scissile for the highlighted backbone bonds, contrasting OH / O / O₃ / H₂O₂ (Findings).
  • Sensitivity: outcomes depend on impinging species identity and collision geometry (50 × 10 run protocol).
  • Limitations / outlook: the model peptidoglycan and simplified plasma proxy omit fields, solvation, and live-cell complexity (## Limitations).
  • Corpus note: bond-level mechanism tables live in the PDF/SI—this page does not duplicate every species-resolved pathway.

Limitations

  • Model peptidoglycan and gas-phase/surface approximations of plasma–bio interaction; full plasma environments include fields, fluxes, and solvation beyond the MD scope summarized here.

Relevance to group

Adri C. T. van Duin (Penn State) coauthors with Antwerp plasma modeling colleagues; extends ReaxFF into plasma–biomaterial reactivity.

Citations and evidence anchors

  • DOI: https://doi.org/10.1021/jp3128516 (papers/Yusupov_Plasma_BacterialWall_JPCC_2013.pdf).