Construction and Application of L-α-Phosphatidylcholine Based Liposomes

What Is L-α-Phosphatidylcholine?

L-α-phosphatidylcholine (PC) is a crucial phospholipid that serves as a fundamental building block for cellular bio-membranes. It is a major phospholipid present in plasma membranes of eukaryotic cells, serving as a vital constituent of cellular membranes and lipoproteins.

Structural Characteristics

L-α-PC is composed of a glycerol backbone esterified with two fatty acids and a phosphatidylcholine head group (choline, phosphate, and glycerol). The head group, derived from phosphocholine, offers the capability to interact with hydrophilic substances, rendering L-α-PC amphipathic. The length and saturation of the fatty acid chains can vary, influencing the fluidity and stability of the resulting lipid bilayer.

Biophysical Properties

The head group of L-α-PC contains a quaternary ammonium of choline, which imparts a positive charge at physiological pH, influencing its behavior and interactions in biological systems. The length and saturation of the fatty acid chains confer distinct biophysical properties to PC, such as membrane fluidity, permeability, and curvature stress.

L-α-PC for Liposome Construction

Liposomes, versatile lipid-based nanocarriers, have garnered significant interest in various scientific disciplines due to their potential applications in vaccine development, drug delivery systems, and nanomedicine. Among the diverse lipid constituents of liposomes, L-α-PC stands out as a highly advantageous and widely used amphiphilic phospholipid.

In order to achieve large-scale production of liposomes, Sang-Won Woo et al. used an injection-molded plastic microfluidic device to achieve high-throughput synthesis of L-α-PC (SOY PC) liposomes.

Schematic diagram of SOY PC liposome synthesis microchannel. [1]

L-α-PC Based Liposome for Vaccine Development

Liposomes, when used as adjuvants, can enhance the efficacy, stability, and immunogenicity of vaccines. L-α-PC, due to its favorable physicochemical properties, plays a significant role in liposome-based vaccine development. L-α-PC incorporation into liposomes modulates the presentation of antigens to the immune system. The characteristic fluidity and biocompatibility of L-α-PC offer flexibility in tailoring liposomal formulations to optimize antigen delivery, stability, and controlled release kinetics.

For example, Zahra Kakhi et al. developed a series of liposomes for antitumor vaccination by the nasal route. The ultra-flexible small unilamellar vesicle (Uf-SUV) vaccine is prepared from SPC (soybean L-a-phosphatidylcholine), SDC (sodium deoxycholate) and ethanol. All three substances contribute to the fluidity of the vesicle membrane. [2]

Liposomal constructs for vaccines. [2]

L-α-PC Based Liposome for Drug Delivery

L-α-PC-derived liposomes hold immense potential in overcoming drug delivery challenges by encapsulating hydrophilic and hydrophobic drugs within their lipid bilayer or aqueous core. Tatiana N. Pashirova et al. designed a novel mixed cationic liposome based on L-α-PC and dihexadecylmethylhydroxyethylammonium bromide (DHDHAB) for use via the intranasal route overcoming the BBB crossing. Results indicate that intranasal administration of 2-PAM-loaded cationic liposomes is effective against paraoxon-induced inhibition of acetylcholinesterase in the brain.

2-PAM-loaded liposomes. [3]

References

1. Woo, Sang-Won, et al. Micromachines, 2021, 12(2), 170.
2. Kakhi, Zahra, et al. Biochimie, 2016, 130, 14-22.
3. Pashirova, Tatiana N., et al. Colloids and surfaces B: biointerfaces, 2018, 171, 358-367.

Our products and services are for research use only and cannot be used for any clinical purposes.