Supramolecular Assemblies of Lipid-Coated Polyelectrolytes

Abstract

We reveal the existence of a general class of supramolecular assemblies made up of lipid-coated polyelectrolytes including the celebrated lipid-nucleic acid complexes. With the aid of high-resolution cryo-electron microscopy, we unveil the nanoscale internal organization of assemblies generated with a wide range of synthetic and biological polyelectrolytes, several of them being investigated in this context for the first time, namely, poly(styrene sulfonic acid), carboxylmethylcellulose, and filamentous actin. Using an original coarse-grained model representing lipid-coated polyelectrolytes as semiflexible tubes, we thoroughly explored the morphologies resulting from the self-assembly process as a function of tube lengths and rigidities; the computed structures are fully consistent with the experimental observations. In particular, we found a strong extension of the correlation range of the order parameter as the rigidity of the lipid-coated polyelectrolytes increases. Electrostatic interactions provide a stabilizing mechanism leading to finite-size equilibrium assemblies. These assemblies may constitute a generic route for interfacing polyelectrolytes to living cells to perform gene delivery, for instance.

Fine Control Over the Size of Surfactant–Polyelectrolyte Nanoparticles by Hydrodynamic Flow Focusing

“…Their faceted shape was very similar to that of our nanoparticles except that the latter were not often perfectly hexagonal. The latter fact may be due to the nature of the polyelectrolyte as it was recently reported that CMC complexed with cationic lipids yielded shapeless nanoparticles with a disordered inner structure …”

“…The latter fact may be due to the nature of the polyelectrolyte as it was recently reported that CMC complexed with cationic lipids yielded shapeless nanoparticles with a disordered inner structure. 29…”

Microfluidics-Driven Strategy for Size-Controlled DNA Compaction by Slow Diffusion through Water Stream

“…Bottom-up nanotechnologies and synthesis of innovative nanomaterials mostly relies on molecular self-assembly, a process by which individual components spontaneously form elaborate ordered structures with emerging functions. , The driving forces pushing molecular subunits toward each other are noncovalent long-range interactions, either weak (H bond, hydrophobicity, entropic effects) or strong (electrostatics, van der Waals forces). − Polyelectrolyte-based complexes constitute an important class of soft nanoparticles that rely on electrostatics for their formation. In their simplest form, they are made of a polyelectrolyte condensed via a coil–globule transition occurring in the presence of oppositely charged agents. − When the polyelectrolyte is made of therapeutic nucleic acids, the resulting complexes hold a great potential for gene therapy.…”

Self-Assembly of Stable Monomolecular Nucleic Acid Lipid Particles with a Size of 30 nm

“…26 Tresset et al explored the morphologies of lipid-coated polyelectrolytes in general, and detailed X-ray studies were carried out on lipid-coated microtubules. 27,28 However, lipid bilayer coating of individual siRNA molecules…”

“…Blessing et al described a template directed chemical synthesis of single plasmid DNA nanoparticles with a diameter of 23 nm, a method that was extended to polymeric lipid DNA particles by Chittimalla et al In our own work, we used block copolymers to encapsulate monomolecular siRNA or short DNA fragments, resulting in 2 nm-sized particles. , Furthermore, the possibility of single DNA strands being enwrapped by a cationic lipid bilayer had been discussed because TEM images provided some evidence of tubular structures connected to DNA lipid particles referred to as “spaghetti”-like objects. , May et al demonstrated theoretically that the coating of DNA by a symmetric bilayer is energetically unfavorable as compared to the bulk hexagonal phase due to high positive curvature of the outer monolayer . Tresset et al explored the morphologies of lipid-coated polyelectrolytes in general, and detailed X-ray studies were carried out on lipid-coated microtubules. , However, lipid bilayer coating of individual siRNA molecules has not yet been reported.…”