Layer by Layer Self-Assembled Polyelectrolyte Multilayers with Embedded Phospholipid Vesicles Obtained by Spraying: Integrity of the Vesicles

Abstract

In a previous paper (Michel, M.; Vautier, D.; Voegel, J.-C.; Schaaf, P.; Ball, V. Langmuir 2004, 20, 4835), we showed that phospholipid vesicles can be incorporated into poly(glutamic-acid)/poly(allylamine) (PGA/PAH) multilayered polyelectrolyte films built by the alternated dipping of a surface in polyanion and polycation solutions. AFM imaging, quartz crystal microbalance, and ellipsometry suggested that the vesicles remain intact when adhering on the surface. In the present paper, we show that such films can also be realized by spraying both the polyelectrolyte solutions and the vesicles onto the surface. Using such vesicles filled with ferrocyanide ions, we prove by cyclic voltammetry that the sprayed vesicles remain intact when embedded in the multilayers. We show that multilayers containing two distinct layers of intact vesicles separated by several polyanion/polycation bilayers can also be constructed. Polyelectrolyte multilayers containing layers of phospholipid vesicles could act as reservoirs for drug or other biologically active molecules in controlled release bioactive coatings.

Electrochemically Stimulated Release from Liposomes Embedded in a Polyelectrolyte Multilayer

“…Ball and coworkers [ 13 ] fi rst combined these benefi ts by embedding polyelectrolyte-stabilized liposomes into a fi lm of poly-L -glutamic acid and poly-(allylamine hydrochloride (PGA-PAH). They were able to employ a quick and effi cient procedure of spraying [ 14,15 ] for the fabrication of such composite fi lms. Finally, they demonstrated the release of fl uorescent dyes contained in the embedded vesicles triggered by temperature increase up to 45 ° C. [ 16 ] Triggered release of drugs from liposomes in various systems without polyelectrolytes has been implemented in several different mechanisms, like light, [ 17,18 ] redox reactions, [ 19 ] ultrasound, [20][21][22] magnetic fi elds, [ 23 ] near IR, [ 24 ] and pH, [ 25,26 ] each with its specifi c advantage depending on application.…”

Spray‐Assisted Polyelectrolyte Multilayer Buildup: from Step‐by‐Step to Single‐Step Polyelectrolyte Film Constructions

“…[62] This was demonstrated on the PGA/PAH (PGA: poly(L-glutamic acid)) system. These authors also showed that one can even incorporate in the multilayer, by spraying, phospholipid vesicles in an intact form.…”

Polyelectrolyte Multilayers: Towards Single Cell Studies

“…However, liposome disruption and fusion at interfaces is often observed [68,69] making the immobilization in multilayers difficult. It has been demonstrated that highly hydrated polyelectrolyte multilayers made from HA and PLL can host polymer-coated (stabilized) vesicles [70][71][72] adsorbed by the LbL approach as shown in Figure 1A,B [73][74][75][76][77]. Detailed analysis of the liposome position within the film has shown that they immerse by about half of their size when they come in contact with the surface of the film.…”