Preparation and Characterization of Two Different Liposomal Formulations with Bioactive Natural Extract for Multiple Applications

By F. Miere (Groza), Simona Cavalu et al.

The aim of this study is to obtain “giant” liposomes by lipid film hydration using a preparation formula with two different phospholipids, phosphatidylcholine (PC) and phosphatidylserine (PS).Firstly, the macro- and microscopic characterization, total phenols content and antioxidant capacity of the plant Stellaria media (L.) Vill. were assessed. Then, Stellaria media (L.) Vill. extract was encapsulated in both formulations (PCE and PSE) and the liposomes were characterized according to their morphology, size distribution and Zeta potential using optical microscopy and dynamic light scattering. The encapsulation efficiency (EE%) was determined using the Folin–Ciocalteu method and the values of both formulations were compared. PC and PCE liposomes with a diameter between 712 and 1000 nm and PS and PSE liposomes with a diameter between 58 and 1000 nm were obtained. The values EE% of Stellaria media (L.) Vill. extract for PCE and PSE were 92.09% and 84.25%, respectively.

Preparation of the liposomes with Stellaria media (L.) Vill. extract and empty liposomes by lipid film hydration. Copyright F. Miere(Groza), Simona Cavalu et al.
Macroscopic and microscopic characteristics of the plant Stellaria media (L.) Vill. (a) The aerial part of the plant Stellaria media (L.) Vill. Stelariae herba (personal photo), (b) flower of the plant Stellaria media (L.) Vill. (personal photo), (c) cross-section through the main stem (100×), (d) longitudinal section through the main stem (200×). Copyright F. Miere (Groza), Simona Cavalu et al.
Microscopic images of the liposomes: (a) Liposomes with phosphatidylcholine (PC), (b) Liposomes with phosphatidylcholine with encapsulated Stellaria media (L.) Vill. extract (PCE), (c) Liposomes with phosphatidylserine (PS), (d) Liposomes with phosphatidylserine with encapsulated Stellaria media (L.) Vill. extract (PSE). The red arrows show the characteristic spherical shape of liposomes. Copyright F. Miere (Groza), Simona Cavalu et al.
Diameter distribution for PC liposomes without encapsulated extract of Stellaria media (L.) Vill. (a) and PCE liposomes with encapsulated extract of Stellaria media (L.) Vill. (b). Copyright F. Miere (Groza), Simona Cavalu et al.

Both PC and PS liposomes and their homologues with encapsulated plant extract were “giant” multilamellar liposomes. In the case of PC and PCE liposomes, around 50–80% presented dimensions between 712 and 1000 nm, while more than 90% of PS and PSE liposomes were in the range of 58–1000 nm. The larger diameter of the PC and PCE liposomes confirmed that the type of phospholipids used in the preparation significantly influenced the size and electrical charge of the formulation. The phosphatidylserine-based formulations showed smaller diameters and a negative Zeta potential, meaning they had better stability compared to phosphatidylcholine-based ones. We also demonstrated a high inclusion percentage of the Stellaria media (L.) Vill. extract in both formulations—more than 90% for PCE and more than 80% for PSE. (Copyright F. Miere (Groza), Simona Cavalu et al.

The full text at https://www.mdpi.com/2227-9717/9/3/432/htm