Effect of doxorubicin on the order of the acyl chains of anionic and zwitterionic phospholipids in liquid-crystalline mixed model membranes: Absence of drug-induced segregation of lipids into extended domains

Biochemistry ◽  
1992 ◽  
Vol 31 (38) ◽  
pp. 9252-9262 ◽  
Author(s):  
Frits A. De Wolf ◽  
Klaas Nicolay ◽  
Ben De Kruijff
Keyword(s):  
Liquid Crystalline ◽  
Mixed Model ◽  
Model Membranes ◽  
Drug Induced ◽  
Acyl Chains

Modifications of lipid structure and their influence on mesomorphism in model membranes: the influence of hydrocarbon chains

1986 ◽  
Vol 64 (1) ◽  
pp. 44-49 ◽  
Author(s):  
K. M. W. Keough
Keyword(s):  
Liquid Crystalline ◽  
Analytical Data ◽  
Model Membranes ◽  
Positional Isomers ◽  
Double Bonds ◽  
Enthalpy Changes ◽  
Hydrocarbon Chains ◽  
Acyl Chains ◽  
Crystalline Phase Transition ◽  
Subsequent Introduction

The influence of hydrocarbon chains on the temperature (TG–LC) of the gel to liquid-crystalline phase transition of model membranes has been investigated over an extensive variety of phosphatidylcholines (PC). The TG–LC is dependent upon the length of the hydrocarbon chains, on whether or not the chains are saturated or have been modified in some way, and on the position of any modification along the chain. For PC having two different acyl chains (heteroacid PC) in the sn-1 and sn-2 positions, the TG–LC is dependent on the chain position and on the inequivalence of chain penetration into the bilayer. Positional isomers of PC have different TG–LC. The first two double bonds introduced in each chain of a PC cause a much greater reduction in TG–LC and in the enthalpy change of the transition than does the subsequent introduction of additional double bonds. Dipolyunsaturated PC have uncooperative (broad) transitions that occur at low temperatures and have small enthalpy changes. While each PC has unique transitional characteristics, there are a number of patterns in the TG–LC which emerge on consideration of all the available data. One such pattern may be useful in predicting TG–LC from analytical data on the composition and positions of acyl chains of various lipids.

scholarly journals Dynamics of phosphatidylcholine-cholesterol mixed model membranes in the liquid crystalline state

1990 ◽  
Vol 57 (3) ◽  
pp. 445-459 ◽  
Author(s):  
Y.K. Shin ◽  
J.K. Moscicki ◽  
J.H. Freed
Keyword(s):  
Crystalline State ◽  
Liquid Crystalline ◽  
Mixed Model ◽  
Model Membranes ◽  
Liquid Crystalline State

scholarly journals Interactions of Linear Analogues of Battacin with Negatively Charged Lipid Membranes

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 192
Author(s):  
Kinga Burdach ◽  
Dagmara Tymecka ◽  
Aneta Urban ◽  
Robert Lasek ◽  
Dariusz Bartosik ◽  
...  
Keyword(s):  
Lipid Membranes ◽  
Liquid Crystalline ◽  
Lipid Membrane ◽  
Attenuated Total Reflection ◽  
Gram Positive ◽  
Insertion Depth ◽  
Force Microscopy ◽  
Acyl Chains ◽  
Hydrophobic Portion ◽  
Membrane Fluidization

The increasing resistance of bacteria to available antibiotics has stimulated the search for new antimicrobial compounds with less specific mechanisms of action. These include the ability to disrupt the structure of the cell membrane, which in turn leads to its damage. In this context, amphiphilic lipopeptides belong to the class of the compounds which may fulfill this requirement. In this paper, we describe two linear analogues of battacin with modified acyl chains to tune the balance between the hydrophilic and hydrophobic portion of lipopeptides. We demonstrate that both compounds display antimicrobial activity with the lowest values of minimum inhibitory concentrations found for Gram-positive pathogens. Therefore, their mechanism of action was evaluated on a molecular level using model lipid films mimicking the membrane of Gram-positive bacteria. The surface pressure measurements revealed that both lipopeptides show ability to bind and incorporate into the lipid monolayers, resulting in decreased ordering of lipids and membrane fluidization. Atomic force microscopy (AFM) imaging demonstrated that the exposure of the model bilayers to lipopeptides leads to a transition from the ordered gel phase to disordered liquid crystalline phase. This observation was confirmed by attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) results, which revealed that lipopeptide action causes a substantial increase in the average tilt angle of lipid acyl chains with respect to the surface normal to compensate for lipopeptide insertion into the membrane. Moreover, the peptide moieties in both molecules do not adopt any well-defined secondary structure upon binding with the lipid membrane. It was also observed that a small difference in the structure of a lipophilic chain, altering the balance between hydrophobic and hydrophilic portion of the molecules, results in different insertion depth of the active compounds.

scholarly journals Non-Lamellar Liquid Crystalline Nanocarriers for Thymoquinone Encapsulation

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 16 ◽  
Author(s):  
Anan Yaghmur ◽  
Boi Vi Tran ◽  
Seyed Moein Moghimi
Keyword(s):  
Liquid Crystalline ◽  
Drug Carriers ◽  
Structural Features ◽  
Drug Induced ◽  
Guest Molecules ◽  
Drug Molecules ◽  
Liquid Crystalline Nanoparticles ◽  
The Mean ◽  
Biological Performance ◽  
Glycerol Monooleate

Owing to their unique structural features, non-lamellar liquid crystalline nanoparticles comprising cubosomes and hexosomes are attracting increasing attention as versatile investigative drug carriers. Background: Depending on their physiochemical characteristics, drug molecules on entrapment can modulate and reorganize structural features of cubosomes and hexosomes. Therefore, it is important to assess the effect of guest molecules on broader biophysical characteristics of non-lamellar liquid crystalline nanoparticles, since drug-induced architectural, morphological, and size modifications can affect the biological performance of cubosomes and hexosomes. Methods: We report on alterations in morphological, structural, and size characteristics of nanodispersions composed from binary mixtures of glycerol monooleate and vitamin E on thymoquinone (a molecule with wide therapeutic potentials) loading. Results: Thymoquinone loading was associated with a slight increase in the mean hydrodynamic nanoparticle size and led to structural transitions from an internal biphasic feature of coexisting inverse cubic Fd3m and hexagonal (H2) phases to an internal inverse cubic Fd3m phase (micellar cubosomes) or an internal inverse micellar (L2) phase (emulsified microemulsions, EMEs). We further report on the presence of “flower-like” vesicular populations in both native and drug-loaded nanodispersions. Conclusions: These nanodispersions have the potential to accommodate thymoquinone and may be considered as promising platforms for the development of thymoquinone nanomedicines.

Interaction of plant viruses and viral coat proteins with mixed model membranes

Biochemistry ◽  
1987 ◽  
Vol 26 (19) ◽  
pp. 6217-6223 ◽  
Author(s):  
Klaas P. Datema ◽  
Ruud B. Spruijt ◽  
Benedictus J. M. Verduin ◽  
Marcus A. Hemminga
Keyword(s):  
Mixed Model ◽  
Plant Viruses ◽  
Model Membranes ◽  
Coat Proteins ◽  
Viral Coat ◽  
Viral Coat Proteins

scholarly journals Infrared Spectroscopic Studies on the Dipalmitoyl Phosphatidylcholine Bilayer Interactions with Calcium Phosphate: Effect of Vitamin D2

2002 ◽  
Vol 16 (3-4) ◽  
pp. 399-408 ◽  
Author(s):  
Neslihan Toyran ◽  
Feride Severcan
Keyword(s):  
Vitamin D ◽  
Calcium Phosphate ◽  
Liquid Crystalline ◽  
Spectroscopic Studies ◽  
The Body ◽  
Head Group ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Major Structural Component ◽  
Ftir Spectral Analysis ◽  
Acyl Chains

In the present work, the interaction of calcium-phosphate with DPPC (dipalmitoyl phosphatidylcholine) model membranes has been studied in the presence and absence of vitamin D2by using Fourier Transform Infrared (FTIR) spectroscopy. Calcium and phosphorus are the most abundant elements in the body. They combine in the form of calcium phosphate salt, called hydroxyapatite. Hydroxyapatite is the major structural component of the bone. Calcium phosphate assists with the digestion and absorption of food and is vitally important for the building of sturdy bone and body structures and a robust constitution. Phosphorus is extracted from foods and its use is controlled by vitamin D and calcium. FTIR spectral analysis results suggested that, calcium–phosphate complex, which is the major component of the bones, decreases the phase transition temperature to lower values, causes a loss in cooperativity of the acyl chains, decreases the order of the membrane in both phases and decreases the dynamics of the membrane in the liquid crystalline phase, increases the flexibility of the chains in the center of the bilayer in both phases, and increases the mobility of the head group of DPPC in the gel phase. The effect of calcium-phosphate on DPPC liposomes diminishes with the addition of vitamin D2into the liposomes. Our results suggest how calcium-phosphate and/or vitamin D2, which have indispensable role for the functioning of the bone tissue, affect the thermal behaviour of DPPC liposomes at molecular level.

Adsorption of cubic liquid crystalline nanoparticles on model membranes

Soft Matter ◽  
2008 ◽  
Vol 4 (11) ◽  
pp. 2267 ◽  
Author(s):  
Pauline Vandoolaeghe ◽  
Adrian R. Rennie ◽  
Richard A. Campbell ◽  
Robert K. Thomas ◽  
Fredrik Höök ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Model Membranes ◽  
Liquid Crystalline Nanoparticles
Sign in / Sign up

Export Citation Format

Share Document