Plant-derived rhamnogalacturonan-I’s modulate proinflammatory cytokine gene expression in neutrophils stimulated by E. coli LPS and P. gingivalis bacteria

Titanium dental implants often induce the foreign body immune response. The duration of the inflammatory process determines the initial stability and biocompatibility of the implant. The challenge for bone tissue engineering is to develop implant biocompatible and bioactive surface coatings that regulate the inflammatory response and enhance osseointegration. Pectins, plant-derived polysaccharides, have been shown to be potential candidates for surface coating due to their possible roles in improving osseointegration and bone healing. The aim of this study was to evaluate in vitro the effect of plant-derived pectin rhamnogalacturonan-I (RG-I) nanocoating on pro- and anti-inflammatory human polymorphonuclear leucocytes (PMN) responses to E. coli LPS or P. gingivalis bacteria. In this study unmodified RG-I and structurally modified RG-I from potato were examined. All in vitro studies were performed on tissue culture polystyrene surfaces (TCPS) or titanium (Ti) discs coated with unmodified and modified RG-Is. Changes in PMN gene expression occurred on both surfaces. The presence of RG-Is down-regulated proinflammatory genes, IL1B, IL8, TNFA. Our results clearly showed that pectin RG-I nanocoating decreased the level of proinflammatory genes expression in stimulated PMN and may therefore be considered as a potential candidate for modulation of the inflammatory response elicited by insertion of implants into living tissue.