Electroformation of liposomes and phytosomes using copper electrode

Abstract

A novel method for electroformation of liposomes and phytosomes using copper electrode is described. Liposomes made at 2 V and 10 Hz AC field from L-α-egg-phosphatidylcholine (egg-PC), K. pneumoniae phosphatidylethanolamine, K. pneumoniae polar lipids and E. coli polar lipids on copper electrode were (777.9 ± 118.4), (370.2 ± 100.5), (825.3 ± 21.54), and (281.3 ± 42.3) nm in diameter, respectively. Giant vesicles were formed at 30 V and 10 Hz AC field from polar lipids of K. pneumoniae and E. coli were (106 ± 29.7) and (86 ± 24.3) µm in diameter, respectively. All liposomes were unilamellar as indicated by their unilamellar indices of 50 ± 2, had surface charge comparable to vesicles made from lipid(s) with similar composition and exhibited only 1–2 mol% of oxidized lipids. Cu concentration in the liposomal samples was <1.5 ppm for large unilamellar vesicles (LUVs) and ˂5 ppm for giant unilamellar vesicles (GUVs). The vesicles were stable for >15 d without loss of their size, charge, or unilamellarity. The method was successfully applied to prepare phytosomes from egg-PC and a phytochemical fraction of Dimorphocalyx glabellus, a medicinal plant with anti-diuretic properties. Phytosomes formed were 1000–1500 nm in diameter and exhibited altered fluorescence and absorbance properties compared to the unencapsulated phytochemical. Phytosomes with phytochemical: egg-PC ratio from 0.15 to 1.5 had encapsulation efficiency ranging 90–30%, respectively, and was stable for 1 month. Our method is easy, inexpensive and convenient that will prove to be useful for preparation of liposomes and phytosomes.