Soy Lecithin-Derived Liposomal Delivery Systems: Surface Modification and Current Applications

Abstract

The development of natural phospholipids for nanostructured drug delivery systems has attracted much attention in the past decades. Lecithin that was derived from naturally occurring in soybeans (SL) has introduced some auspicious accomplishments to the drug carrying aspect, like effectual encapsulation, controlled release, and successful delivery of the curative factors to intracellular regions in which they procure these properties from their flexible physicochemical and biophysical properties, such as large aqueous center and biocompatible lipid, self-assembly, tunable properties, and high loading capacity. Despite the almost perfect properties as a drug carrier, liposome is known to be quite quickly eliminated from the body systems. The surface modification of liposomes has been investigated in many studies to overcome this drawback. In this review, we intensively discussed the surface-modified liposomes that enhancing the targeting, cellular uptake, and therapeutic response. Moreover, the recent applications of soy lecithin-derived liposome, focusing on cancer treatment, brain targeting, and vaccinology, are also summarized.

Keywords: drug delivery system; liposome; soy lecithin; surface modification.

Figure 1

Chemical formulas of different phospholipid-derived lecithin. Shown in red—phosphate group; green—monounsaturated fatty acid; blue—saturated fatty acid; pink—choline (a), ethanolamine (b), inositol (c), serine (d), and glycerol (e).

Figure 2

Classification of liposomes and the surface modification strategies applied in each category. (A) Conventional liposomes simply contain: neutral, anionic, and cationic phospholipids; (B) stealth liposomes are PEGylated contain a polyethylene glycol (PEG) layer; (C) multifunctional liposomes have modified surfaces in addition to carrying imaging agent for diagnostic purposes (diagnosis and treatment functions); and, (D) targeted liposomes have modified surfaces through the attachment of targeting ligands (antibody, protein, peptide, small molecule, carbohydrate). [21].

Figure 3

Comparison of PEGylated liposome with conventional liposome. PEGylated liposome: high molecular size, high solubility, and shielding against the recognition by opsonin. Conventional liposome: small molecular size, low solubility, and recognition by opsonin.

Figure 4

Receptors (intracellular and extracellular) that can be targeted using ligand-targeted liposomes for the delivery of anticancer drugs. Targets could also be specific organelles (mitochondria and lysosomes) [21].

Figure 5

The mechanism of drug delivery across the BBB using ligand-targeted immunoliposomes.