Restorative potential of laser-synthesized silver nanoparticles with Salvia officinalis for periodontal disease treatment: an in vitro study

Periodontal disease is one of the most prevalent human pathologies initiated by microbial dysbiosis and the inflammatory reaction that leads to gingival fibroblasts apoptosis, connective tissue damage, and atrophy, resulting in tooth loss. Beyond local damage, systemic associations highlight the urgent need for innovative therapies. Herein, we present an eco-friendly synthesis of silver nanoparticles (AgNPs) by picosecond pulsed laser ablation in liquid (PLAL), using Salvia officinalis aqueous extract (sage extract) as both medium and stabilizer. AgNPs were synthesized at two laser pulse energies (2 and 6 mJ), in sage extract and deionized water, and characterized by dynamic light scattering, transmission electron microscopy, and inductively coupled plasma optical emission spectroscopy. Synthesis at 6 mJ in sage extract ( _Sage AgNPs _6mJ ) yielded well-dispersed, spherical nanoparticles (7.98 ± 2.9 nm) at a concentration of 21.6 ± 1.75 mg·L ⁻¹ . _Sage AgNPs _6mJ exhibited potent antibacterial activity against Aggregatibacter actinomycetemcomitans , Fusobacterium nucleatum , and Porphyromonas gingivalis (MIC = 5.4 mg·L ⁻¹ ), and showed equal or superior antibacterial activity compared to 0.2% chlorhexidine. Importantly, at MIC concentration, _Sage AgNPs _6mJ were non-cytotoxic to primary human gingival fibroblasts and enhanced their proliferation by approximately 50% after 24 h. This was shown by increased Ki-67 proliferation index, increased type-I and total collagen production up to 11% after 24 h and significantly reduced IL-6 by 23% after 24 h, which returned to the baseline levels after 48 h. These findings define a clear therapeutic window, where the same concentration that eradicates bacteria also promotes gingival cell regeneration and reduces inflammation. This dual antibacterial and regenerative action demonstrates the high potential of sage-assisted PLAL-synthesized AgNPs as a safe, sustainable strategy for periodontal disease treatment.