Paper Title
INVERSE EMULSION TECHNIQUE TO PRODUCE FLEXIBLE ASYMMETRIC LIPOSOMES FOR GENETIC MATERIAL ENCAPSULATION.

Abstract
For decades, different nanocarriers for drug delivery have been explored, such as liposomes, which are artificial spherical shape vesicles composed of lipid bilayers; this kind of nanocarriers have gained importance because of their improved characteristics, such as biodegradability and low toxicity. There are different types of liposomes: symmetric ones (the same lipids composition in the inner and outer layers) and asymmetric ones (different lipids in the inner and outer parts of the bilayer). Asymmetric vesicles have advantages such as optimizing the charges, encapsulation efficiency, and drug leakage reduction. Transdermal delivery of liposomes is also attractive to the pharmaceutical industry. It is a viable alternative for optimizing problems such as poor biodistribution, off-target side effects, and a short circulation time. Also, these vesicles can protect molecules such as nucleic acids, giving them importance in molecular medicine. Asymmetric liposomes promise a viable alternative for loading genetic material, but their use as transdermal drug delivery systems has not been explored. During this study, asymmetric flexible liposomes for DNA encapsulation were designed through the inverse emulsion technique, expecting these liposomes to be applied by the transdermal route. Six different liposome formulations were synthesized using the cationic lipid 1,2-di-O-octadecenyl-3-trimethylammonium propane (DOTMA) and helper lipid 1,2-Dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) for the inner layer. For the outer layer, the neutral lipid 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) was used. Components for flexibility(ethanol and span 80 surfactant) and stability (cholesterol) were used in different molar ratios. Each formulation was characterized by transmission electron microscopy (TEM), particle size distribution, encapsulation efficiency (%EE), andflexibility index through the extrusion method. Keywords - Nanocarriers, Asymmetric Liposome, Symmetric Liposome, Nucleic Acid.