Liposomes are vesicular biocompatible nano and micro-particles formed by one or more lipid bilayer membranes that surrounds an aqueous core. The amphiphilic structure of liposome particles enables encapsulation of both hydrophilic and hydrophobic pharmaceutical drugs and nutrients. This makes liposomes very attractive biological systems that are widely employed as drug delivery vehicles as part of an expanding market.
Liposome vescicular structure
Microfluidic Method vs Batch Method for liposome production
Microfluidic methods have demonstrated potential for achieving higher control over the physical properties of the final liposome product than conventional batch methods. Small liposome nanoparticles with narrow size distribution and high drug encapsulation efficiency can be produced using microfluidic hydrodynamic focusing (MHF) techniques. This has been demonstrated in the article published by D. Carugo et al. in 2016 “Liposome production by microfluidics: potential and limiting factors” Sci. Rep., 6, 25876.
Schematic representation of a MHF system
MHF methods rely on the use of microfluidic devices with a cross flow geometry. Typically, a stream of lipid in alcohol solution is forced to flow in inner channel of the device. The lipid stream is intersected and sheathed by two lateral (or coaxial) streams of a water phase (distilled water or aqueous buffers). In this way, the lipid containing stream is hydrodynamically focused into a narrow sheet.
The size of the focused stream and the resulting liposome formulation can be tuned by adjusting the volumetric flow rate ratio (FRR) between the lipid and water phase streams, and the total flow rate (TFR). The formation of liposomes in MHF chips is governed by the diffusion at the liquid interface between the solvent (alcohol) and non-solvent (water) phases. The alcohol in which the lipids are initially solubilised diffuses into the water until the alcohol concentration decreases below the solubility limit of the lipids. As such, the alcohol diffusion triggers the formation of liposomes by a mechanism described as “self-assembly”.
Systems for liposome synthesis and drug encapsulation
- Encapsulate drugs in liposomes
- Quick and reproducible liposome synthesis
- Wide range of liposome sizes
- Highly monodisperse particles
- Batch sizes from few milliliters to several liters
- Flexible system for easy scale-up
Dolomite's Liposome Synthesis System is a complete system for generating liposomes and encapsulating drugs. Based on Dolomite’s extensive range of high quality glass chips, the system uses microfluidics to precisely make capsules with specific diameters. It is compact, modular and easy-to-use.
Read more about liposome synthesis here.