Bilayer fluidity of non-ionic vesicles. An investigation by differential polarized phase fluorometry

Ribier, A.; Handjani‐Vila, R. M.; Bardez, Élisabeth; Valeur, Bernard

doi:10.1016/0166-6622(84)80017-7

Cited by 15 publications

(4 citation statements)

References 8 publications

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“…The fluorescence anisotropy for Tw20-ders:CHOL formulations (sample 1: 0.15±0.2; sample 2: 0.23±0.3; sample 3: 0.25± 0.2) provide evidence that vesicular samples prepared with Tw20-GLY (sample 1) displayed a more fluid bilayer. This is in keeping with previous work reporting that bilayer fluidity is affected not only by the kind of hydrocarbon chains but also by the polar head groups (Ribier et al 1984). So differences in anisotropy florescence values for Tw20-ders:CHOL samples could be related to polar head group, and in particular, to the packing density of the membrane.…”

Section: Resultssupporting

confidence: 91%

“…At 25 °C sample 1 showed an increase in vesicle dimensions and a decrease in z-potential values indicating that changes in physical stability of the formulations occurred. Such reduced colloidal stability for sample 1 can be attributed to higher bilayer fluidity, in fact it is known that stability of vesicular structure is strongly dependent on the fluidity of the bilayer since the vesicle is constructed by the assembly of amphiphilic molecules without any chemical bonding (Ribier et al 1984).…”

Section: Resultsmentioning

confidence: 99%

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Interaction of pH-sensitive non-phospholipid liposomes with cellular mimetic membranes

Marianecci

Rinaldi

Marzio

et al. 2012

Biomed Microdevices

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Surfactant nanocarriers have received considerable attention in the last several years as interesting alternative to classic liposomes. Different pH-sensitive vesicular colloidal carriers based on Tween 20 derivatives, obtained after functionalization of the head groups of the surfactant with natural, or simply modified, amino acids, were proposed as drug nanocarriers. Dynamic light scattering, Small Angle X-ray Scattering, Trasmission Electron Microscopy and fluorescence studies were used for the physico-chemical characterization of vesicles and mean size, size distribution, zeta potential, vesicle morphology and bilayer properties were evaluated. The pH-sensitivity and the stability of formulations, in absence and in presence of foetal bovine serum, were also evaluated. Moreover, the contact between surfactant vesicles and liposomes designed to model the cellular membrane was investigated by fluorescence studies to preliminary explore the potential interaction between vesicle and cell membranes. Experimental findings showed that physico-chemical and technological features of pH-sensitive vesicles were influenced by the composition of the carriers. Furthermore, proposed carriers are able to interact with mimetic cell membrane and it is reasonable to attribute the observed differences in interaction to the architectural/structural properties of Tween 20 derivatives. The findings reported in this investigation showed that a deep and extensive physico-chemical characterization of the carrier is a fundamental step, according to the evidence that the knowledge of nanocarrier properties is necessary to translate its potentiality to in vitro/in vivo applications.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Interaction of pH-sensitive non-phospholipid liposomes with cellular mimetic membranes

Marianecci

Rinaldi

Marzio

et al. 2012

Biomed Microdevices

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“…38,49 Cholesterol exclusion or demixing is then expected to play a role in niosome structure and stability. When mixed with phospholipids in membranes, in some range of relative concentration, cholesterol is known to give rise to a remarkable phase, known as the lo phase, 50 where crystallinity and local order are decoupled. Intrachain and interchain mobility loose the usual parallel behavior due to cholesterol intercalation.…”

Section: Resultsmentioning

confidence: 99%

Niosomes as Drug Nanovectors: Multiscale pH-Dependent Structural Response

et al. 2016

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The use of nanocarriers, which respond to different stimuli controlling their physicochemical properties and biological responsivness, shows a growing interest in pharmaceutical science. The stimuli are activated by targeting tissues and biological compartments, e.g., pH modification, temperature, redox condition, enzymatic activity, or can be physically applied, e.g., a magnetic field and ultrasound. pH modification represents the easiest method of passive targeting, which is actually used to accumulate nanocarriers in cells and tissues. The aim of this paper was to physicochemically characterize pH-sensitive niosomes using different experimental conditions and demonstrate the effect of surfactant composition on the supramolecular structure of niosomes. In this attempt, niosomes, made from commercial (Tween21) and synthetic surfactants (Tween20 derivatives), were physicochemically characterized by using different techniques, e.g., transmission electron microscopy, Raman spectroscopy, and small-angle X-ray scattering. The changes of niosome structure at different pHs depend on surfactants, which can affect the supramolecular structure of colloidal nanocarriers and their potential use both in vitro and in vivo. At pH 7.4, the shape and structure of niosomes have been maintained; however, niosomes show some differences in terms of bilayer thicknesses, water penetration, membrane coupling, and cholesterol dispersion. The acid pH (5.5) can increase the bilayer fluidity, and affect the cholesterol depletion. In fact, Tween21 niosomes form large vesicles with lower curvature radius at acid pH; while Tween20-derivative niosomes increase the intrachain mobility within a more interchain correlated membrane. These results demonstrate that the use of multiple physicochemical procedures provides more information about supramolecular structures of niosomes and improves the opportunity to deeply investigate the effect of stimuli responsiveness on the niosome structure.

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“…The high structural stability of niosomes is due to their high surface density of hydrated groups. Niosomes are more chemically stable and have lower cost than liposomes made of phospholipids 154. Niosomes coated with O ‐palmitoyl mannan (a ligand of the mannose receptor in APC) containing HBsAg elicited Ag‐specific antibodies (serum and mucosal) and cellular response.…”

Section: Oral Routementioning

confidence: 99%

Topical and mucosal liposomes for vaccine delivery

Romero

Morilla

2011

WIREs Nanomed Nanobiotechnol

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Mucosal (and in minor extent transcutanous) stimulation can induce local or distant mucosa secretory IgA. Liposomes and other vesicles as mucosal and transcutaneous adjuvants are attractive alternatives to parenteral vaccination. Liposomes can be massively produced under good manufacturing practices and stored for long periods, at high antigen/vesicle mass ratios. However, their uptake by antigen-presenting cells (APC) at the inductive sites remains as a major challenge. As neurotoxicity is a major concern in intranasal delivery, complexes between archaeosomes and calcium as well as cationic liposomes complexed with plasmids encoding for antigenic proteins could safely elicit secretory and systemic antigen-specific immune responses. Oral bilosomes generate intense immune responses that remain to be tested against challenge, but the admixing with toxins or derivatives is mandatory to reduce the amount of antigen. Most of the current experimental designs, however, underestimate the mucus blanket 100- to 1000-fold thicker than a 100-nm diameter liposome, which has first to be penetrated to access the underlying M cells. Overall, designing mucoadhesive chemoenzymatic resistant liposomes, or selectively targeted to M cells, has produced less relevant results than tailoring the liposomes to make them mucus penetrating. Opposing, the nearly 10 µm thickness stratum corneum interposed between liposomes and underlying APC can be surpassed by ultradeformable liposomes (UDL), with lipid matrices that penetrate up to the limit with the viable epidermis. UDL made of phospholipids and detergents, proved to be better transfection agents than conventional liposomes and niosomes, without the toxicity of ethosomes, in the absence of classical immunomodulators.

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Bilayer fluidity of non-ionic vesicles. An investigation by differential polarized phase fluorometry

Cited by 15 publications

References 8 publications

Interaction of pH-sensitive non-phospholipid liposomes with cellular mimetic membranes

Interaction of pH-sensitive non-phospholipid liposomes with cellular mimetic membranes

Niosomes as Drug Nanovectors: Multiscale pH-Dependent Structural Response

Topical and mucosal liposomes for vaccine delivery

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