Phosphatidylserine (PS) and phosphatidylglycerol (PG) nanodispersions as potential anti-inflammatory therapeutics: Comparison of in vitro activity and impact of pegylation.

Phosphatidylserine (PS) and phosphatidylglycerol (PG) are endogenous phospholipids with putative anti-inflammatory potential. However, studies comparing PS and PG are rare and were mainly conducted with phospholipid-dispersions of large size and broad distributions. Thus, we prepared small-sized PS- and PG-loaded liposomes exhibiting narrow distribution, and additionally studied the impact of liposome-pegylation on the reduction of the TNFα-production caused by the PS- and PG-liposomes. These PS- and PG-containing nanodispersions had a small size around 100nm and a narrow distribution (PDI<0.1). The liposome-dispersions showed no toxicity in NHDF- and 3T3-cells and virtually no hemolytic activity. They decreased the TNFα-production of LPS-(lipopolysaccharide)-stimulated mouse peritoneal macrophages in vitro. PG-liposomes always decreased the TNFα-levels more potently than PS-liposomes. Pegylation of PS- and PG-liposomes caused different Zeta potentials, but did not change biological activity. The results of the current study indicate a high potential of the tested formulations for phospholipid-based anti-inflammatory therapies.