Development of a Platform of Antibody-Presenting Liposomes

Abstract

Antibody-presenting liposomes present high interest as drug delivery systems. The association of antibodies to liposomes is usually realized by covalent coupling of IgGs or their antigen-binding fragments to lipid polar head groups by means of hetero-bifunctional crosslinkers. We present here an original platform of IgGpresenting liposomes which is based on a fusion protein between Annexin-A5 (Anx5) and the IgG-binding ZZ repeat derived from Staphylococcus aureus protein A. The Anx5ZZ fusion protein acts as a bi-functional adaptor that anchors IgGs to liposomes in a non covalent and highly versatile manner. The interactions between IgGs, Anx5ZZ and liposomes were characterized by PAGE, dynamic light scattering and fluorescence quenching assays, establishing that binding of Anx5ZZ to IgGs and of Anx5ZZ-IgG complexes to liposomes is complete with stoichiometric amounts of each species. We found that the sequence of assembly is important and that Anx5ZZ-IgG complexes need to be formed first in solution and then adsorbed to liposomes in order to avoid aggregation. The targeting capacity of Anx5ZZ-IgG-functionalized liposomes was demonstrated by electron microscopy on an ex vivo model system of atherosclerotic plaques. This study shows that the Anx5ZZ adaptor constitutes an efficient platform for functionalizing liposomes with IgGs. This platform may present potential applications in molecular imaging and drug delivery.

Nanoparticle-based bioactive agent release systems for bone and cartilage tissue engineering

“…EPR effect is a “gold standard” for the anticancer drug design and for targeting sites of tissue inflammation [27], [28], [29], [30]. Targeting to specific tissues is the most promising attribute of the NPs [14], [31], [32]. Therefore, to reach that capability, it is needed the covalent attachment of a defined ligand at the surface of the NP, which will specifically interact with antigens or receptors expressed at the surface of the target cells [33].…”

Biophysical and Structural Studies of Escherichia coli Mechanosensitive Channel of Large Conductance in Lipid Bilayers

“…Second, liposomes are easily modifiable to accommodate various properties/function (Levchenko et al, 2012;Slingerland et al, 2012). For example, antibodies and polyethylene glycols can be added to improve their target specificity as well as reduced immunogenicity (Garnier et al, 2012;Wolff et al, 2010), and lipid composition has also been varied for improved solubility of specific drugs (Slingerland et al, 2012). Third, liposomes can be easily adsorbed by tissues, as evidenced by topical liposomes commonly used by the cosmetic industry (Betz et al, 2005;Posner, 2002) as well as for topical nystatin formulations (Torchilin, 2005).…”

“…With the second, it is possible to produce stable modifiable liposomes smaller than 100 nm, which is small enough to cross the blood-brain barrier. With the third challenge, liposomes which directly release drugs at the target site via nanovalves and those which undergo receptormediated fusion to the target cells are currently under development (Garnier et al, 2012;Nakayama et al, 2015).…”

“…1.4C) (Basile et al, 2012;Garnier et al, 2012;Lammers et al, 2012;Sawant & Torchilin, 2012). The specificity of these affinity tags can range from fairly low (e.g.…”

“…Smaller liposomes are generally favoured for drug delivery because they tend to be more permeable to physiological barriers such as blood vessels (Garnier et al, 2012). There are conflicting hypotheses, both based on molecular dynamics studies, on the influence of global curvature in small liposomes on MscL function (Bavi, Cox, et al, 2016;Meyer et al, 2006), making an experimental confirmation of whether MscL is to be engineered for gating threshold (Iscla et al, 2013;Nakayama et al, 2015).…”