Lipopolysaccharides are endotoxins composed of lipopolysaccharide structures and serve as TLR-4 activators, triggering pathogen-associated molecular patterns (PAMP) of the immune system and inducing cellular secretion of vesicles. Extracted from the outer leaflet of the outer membrane of Gram-negative bacteria, they consist of an O-antigen-specific chain, a core oligosaccharide, and lipid A. Lipopolysaccharides, from P. gingivalis, refer specifically to the endotoxin derived from Porphyromonas gingivalis.