Injectable Nanogel of Centella Asiatica and Punica Granatum Extracts as Adjunctive Therapy Enhanced by Photobiomodulation for Periodontitis: A review

Background: Periodontitis is a chronic inflammatory disease characterized by irreversible destruction of periodontal tissues, driven by dysbiotic biofilms and exacerbated by host‐mediated inflammation. Conventional scaling and root planing (SRP) often fails to reach pathogens within deep pockets and complex anatomy. 
Objective: To review formulation, antimicrobial efficacy, and regenerative capacity of injectable nanogels co‐encapsulating P. granatum and C.asiatica extracts as adjunctive therapy to SRP, and to evaluate the added benefits of photobiomodulation therapy (PBMT). 
Method(s): Systematic search was conducted using PubMed and Scopus to identify In vitro, ex vivo, and clinical studies on injectable nanogels containing P. granatum and C. asiatica, with or without photobiomodulation therapy (PBMT), following PRISMA guidelines. Data extracted included formulation characteristics, release kinetics, biofilm penetration, antimicrobial activity, and clinical outcomes such as attachment level. Findings were synthesized narratively to evaluate the therapeutic potential across various models. 
Results: Nanogels demonstrated sustained phytochemical release, enhanced mucoadhesion, and deep penetration into Porphyromonas gingivalis biofilms, achieving >90% bacterial kill In vitro and improved clinical parameters in human trials. P. granatum tannins disrupted bacterial membranes and inhibited biofilm formation, while C. asiatica triterpenoids modulated inflammation and stimulated fibroblast proliferation and angiogenesis. PBMT further amplified therapeutic effects by increasing mitochondrial ATP production, reducing oxidative stress, downregulating pro‐inflammatory cytokines, and promoting osteogenic differentiation and collagen remodeling. 
Conclusion: Injectable nanogels co‐delivering P. granatum and C. asiatica extracts, augmented by PBMT, offer a synergistic approach for enhanced periodontal therapy.