Plasma-engineered microalgal coatings for modulating inflammation, preventing infection, and promoting tissue homeostasis

<h2>Summary</h2> The failure to restore tissue homeostasis at implanted device interfaces drives chronic inflammation, infection, and impaired healing. We report a multifunctional bioactive coating derived from <i>Spirulina maxima</i> and <i>Spirulina platensis</i> using a single-step, solvent-free atmospheric plasma jet (APJ) process. APJ treatment disrupts <i>Spirulina</i> cell walls and reassembles the biomass into a continuous adherent film enriched with native polysaccharides, peptides, and polyphenols without chemical modification. The coatings stably integrate onto wound dressings and orthopedic-grade magnesium implants. In rat full-thickness skin wounds and cranial defects, the plasma-engineered coatings significantly reduced inflammatory infiltration and edema, suppressed bacterial colonization without antibiotics, and enhanced angiogenesis and collagen deposition. They further promoted fibroblast and keratinocyte proliferation, supported osteogenic differentiation, and accelerated tissue regeneration. The coatings retained long-term bioactivity without cytotoxic effects. This drug-free, plasma-enabled platform offers a scalable strategy for immune modulation, infection control, and regenerative repair at biomaterial interfaces.