Membrane contactor method is a new technology for preparing the SLN. In this technology, the liquid phase is pressed through the membrane hole at a temperature higher than the melting point of the lipid, allowing the formation of small droplets as shown in Fig. 1. The aqueous phase is continuously stirred and circulates tangentially in the membrane module to sweep away the droplets formed at the hole outlets. The prepared material was cooled at room temperature to form SLN. Here, both phases are placed in a thermostatic bath to maintain the required temperature, and nitrogen is used to create the pressure for the liquid phase. The membrane contactor method is also used for the preparation of polymer nanoparticles, including the polymerization of dispersed monomers (interfacial polymerization) or the dispersion of prefabricated polymers (nano precipitation). The advantage of using the membrane contactor to prepare SLN is easy to use. The size and amplification ability of SLN can be controlled by selecting appropriate process parameters.
Fig.1 Schematic drawing of the membrane contactor for the preparation of SLN. (Charcosset, 2005)
Scientists have studied the preparation of nanoparticles by membrane contactor to realize the large-scale production of nanoparticles. The organic phase is pressed through the membrane pores to form small droplets. The reaction takes place between organic phase droplets and aqueous phase droplets flowing tangentially to the membrane surface. The two main parameters of the process are water phase cross-flow velocity and organic phase pressure. The results show that with 1000 Da nanofiltration membrane, nanoparticles with a transmembrane pressure of 3×105 Pa (3 bar), a cross-flow rate of 1.7ms-1 and a size of 260 nm can be prepared. The 0.1 m pore size microfiltration membrane (1.6m3/h m2) has high flux, and 1.8×10−3 m3 nanoparticles can be prepared in 4 min with an average particle size of 360 nm. In this study, the fluxes obtained are very high, which makes it possible to expand the industrial applications. Other advantages of this membrane reactor are its versatility for the preparation of either nanocapsules or nanospheres, by methods involving polymerization of dispersed monomers or dispersion of preformed polymers, and the control of the size of the average nanoparticles by an appropriate choice of the membrane.
Fig.2 Experimental set-up for the preparation of nanoparticles. M: manometer. (Charcosset, 2005)
Creative Biolabs is a world-leading biotechnology company. Our expertise is completed by a team of strategic consultants and technical advisors who are among the most renowned experts in their fields. We will work with you as part of your team to provide timely and effective solutions to any challenges that you face in mRNA delivery. Please contact us for more information and a detailed quote.
Reference
