Identification of large channels in cationic PEGylated cubosome nanoparticles by synchrotron radiation SAXS and Cryo-TEM imaging.

Extra-large nanochannel formation in the internal structure of cationic cubosome nanoparticles results from the interplay between charge repulsion and steric stabilization of the lipid membrane interfaces and is evidenced by cryogenic transmission electron microscopy (Cryo-TEM) and synchrotron radiation small-angle X-ray scattering (SAXS). The swollen cubic symmetry of the lipid nanoparticles emerges through a shaping transition of onion bilayer vesicle intermediates containing a fusogenic nonlamellar lipid. Cationic amphiphile cubosome particles, thanks to the advantages of their liquid crystalline soft porous nanoarchitecture and capability for multi-drug nanoencapsulation, appear to be of interest for the design of mitochondrial targeting devices in anti-cancer therapies and as siRNA nanocarriers for gene silencing.

Earliest stage of the tetrahedral nanochannel formation in cubosome particles from unilamellar nanovesicles.

Studies of nonequilibrium lipid polymorphism at the nanoscale contribute to the in-depth understanding of the structural pathways for formation of aqueous channels and emerging of channels-network ordering in liquid-crystalline (LC) nanovehicles. We present experimental structural evidence for the smallest tetrahedral-type lipid membrane aggregate, which involves completely formed nanochannels and occurs as an early intermediate state during the bilayer vesicle-to-cubosome particle transition. Nanovehicles are generated from a self-assembled lipid mixture and studied by means of high-resolution cryogenic transmission electron microscopy (cryo-TEM) and synchrotron radiation small-angle X-ray scattering (SAXS).

Self-assembled multicompartment liquid crystalline lipid carriers for protein, peptide, and nucleic acid drug delivery.

Lipids and lipopolymers self-assembled into biocompatible nano- and mesostructured functional materials offer many potential applications in medicine and diagnostics. In this Account, we demonstrate how high-resolution structural investigations of bicontinuous cubic templates made from lyotropic thermosensitive liquid-crystalline (LC) materials have initiated the development of innovative lipidopolymeric self-assembled nanocarriers. Such structures have tunable nanochannel sizes, morphologies, and hierarchical inner organizations and provide potential vehicles for the predictable loading and release of therapeutic proteins, peptides, or nucleic acids.

SAXS investigation of a cubic to a sponge (L3) phase transition in self-assembled lipid nanocarriers.

The encapsulation and release of peptides, proteins, nucleic acids, and drugs in nanostructured lipid carriers depend on the type of the self-assembled liquid-crystalline organization and the structural dimensions of the aqueous and membraneous compartments, which can be tuned by the multicomponent composition of the systems. In this work, small-angle X-ray scattering (SAXS) investigation is performed on the 'melting' transition of the bicontinuous double diamond cubic phase, formed by pure glycerol monooleate (MO), upon progressive inclusion of varying fractions of pharmaceutical-grade glycerol monooleate (GO) in the hydrated system. The self-assembled MO/GO mixtures are found to form diamond (Pn3m) inverted cubic, inverted hexagonal (H(II)), and sponge (L(3)) phases at ambient temperature in excess of aqueous medium without heat treatment.

[Effect of feed antibiotics on ampicillin pharmacokinetics in chickens].

Experimental studies with broiler birds revealed that medicated feed (flavophospholipol, vitamyacin A, and the A-149 antibiotic in stimulative doses), offered in the course of two weeks, led to changes in the pharmacokinetic parameters of ampicillin administered i/v (in the form of ampicillin-Na) and via the crop (in the form of ampicillin-trihydrate at 30 mg/kg). It was found that the biologic half-life of ampicillin-Na was prolonged by A-149, and was shortened by vitamicin A, and to a certain extent--by flavophospholipol; the seeming volume of distribution was shown to rise by A-149, and to a certain extent--by flavophospholipol, and was lowered by vitamycin A. The biologic half-life of ampicillin-trihydrate was prolonged by all three ergotropic agents.