Why do «empty» liposomes have their own biological activity?

Abstract

It is well known, that liposomes are successfully used, first of all, in pharmacology and pharmacotherapy, for drug delivery, but their own biological activity cannot be excluded. The data obtained clearly demonstrate, that even empty (i. e., containing no active substances in their internal cavity or membrane) phosphatidylcholine liposomes (PCL), i. e. liposomes per se, possess an amazing ability to normalize the contractile activity of blood vessels impaired under hypoxia, restore endothelial function at arterial hypertension and diabetes, and even to renovate endothelium-dependent relaxant vascular function damaged after exposure to ionized γ-radiation. It was shown also that liposomes per se effectively restored Maxi-K channels activity damaged following genotoxic oxidative stress induced by γ-radiation. Thus, empty phosphatidylcholine liposomes have a pronounced intrinsic biological activity regarding vascular tissues. This is a really surprising discovery and these effects may be due to their ability to influence the phospholipid environment of ion channels and, thereby, to modulate ion channel functional activity.