Exploring the utility of hybrid siloxane-phosphocholine (SiPC) liposomes as drug delivery vehicles

Hybrid siloxane-phosphocholines (SiPCs) are a unique class of lipids that possess the capacity to spontaneously form unilamellar vesicles (ULVs) that are ∼100 nm in diameter upon exposure to aqueous media without the need for extrusion. These hybrid SiPCs do not negatively impact the growth of a number of bacterial strains and were subsequently explored as candidates for the delivery of a model compound, calcein. Liposomes that were formed spontaneously encapsulated larger quantities of calcein than liposomes that were formed via extrusion (both SiPCs and commercially available lipids), indicating that the extrusion process results in the loss of the material being entrapped and decreased entrapment efficiency. Although the percentage of calcein released was virtually identical across liposome samples (extruded and non-extruded), the greater entrapment efficiency of the spontaneously formed liposomes ultimately results in a greater payload delivery. Hybrid siloxane-phosphocholines (SiPCs) are a unique class of lipids that spontaneously form unilamellar vesicles (ULVs) that are ∼100 nm in diameter upon exposure to aqueous media without the need for extrusion and can be used as delivery vehicles.