The chain conformational order of ergosterol- or cholesterol-containing DPPC bilayers as modulated by Amphotericin B: a FTIR study

Fournier, Isabelle; Barwicz, Joanna; Auger, Michèle; Tancrède, Pierre

doi:10.1016/j.chemphyslip.2007.09.006

Cited by 41 publications

(40 citation statements)

References 52 publications

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“…As reported in other studies, hydrophobic interactions between molecules and the aliphatic chains of phospholipids are important in determining the physical properties of a membrane. This kind of interaction was also suggested for Amphotericin B and ergosterol-containing DPPC vesicles [38]. Our Figure S1) implies the presence of a new domain formed by interactions between CLX and cholesterol, which in turn interact with DSPC.…”

Section: Dsc Studiessupporting

confidence: 75%

Celecoxib-loaded liposomes: effect of cholesterol on encapsulation and in vitro release characteristics

et al. 2010

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CLX (celecoxib) is a highly hydrophobic non-steroidal anti-inflammatory drug with high plasma protein binding. We describe here the encapsulation of CLX in MLVs (multilamellar vesicles) composed of DSPC (1,2-distearoyl-sn-glycero-3-phosphocholine) and variable amounts of cholesterol. The effects of cholesterol content on liposome size, percentage drug loading and in vitro drug release profiles were investigated. Differential scanning calorimetry and FTIR (Fourier-transform infrared) spectroscopy were used to determine molecular interactions between CLX, cholesterol and DSPC. The phase transition temperature (Tm) of vesicles was reduced in a synergistic manner in the presence of both CLX and cholesterol. Encapsulation efficiency, loading and release of CLX decreased with increasing cholesterol content. FTIR results indicated that this decrease was due to a competition between CLX and cholesterol for the co-operativity region of the phospholipids. In the presence of cholesterol, CLX was pushed further into the hydrophobic core of the bilayer. However, MLVs prepared with DSPC only (without cholesterol) exhibited the lowest ability for drug retention after 72 h. Our results indicated that CLX, without the requirement of modifications to enhance solubilization, can be encapsulated and released from liposomal formulations. This method of drug delivery may be used to circumvent the low bioavailability and systemic side effects of oral CLX formulations.

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Section: Dsc Studiessupporting

confidence: 75%

Celecoxib-loaded liposomes: effect of cholesterol on encapsulation and in vitro release characteristics

et al. 2010

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“…It has been also proposed that selectivity toward cells of fungi is based upon a difference of the radii of porous structures of AmB binding ergosterol and cholesterol [6,9]. On the other hand, very recent reports show that alternatively both the biological action of the drug as well as toxic side effects may be directly related to the effect of AmB on physical properties of the membranes [10][11][12][13]. The 1 H-NMR technique studies demonstrated that the polar headgroup region of the membranes, rather than the hydrophobic core, is a predominant site of binding of AmB from the water phase [12].…”

Section: Introductionmentioning

confidence: 99%

Molecular organization of antifungal antibiotic amphotericin B in lipid monolayers studied by means of Fluorescence Lifetime Imaging Microscopy

Gruszecki

Luchowski

Gagoś

et al. 2009

Biophysical Chemistry

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Amphotericin B (AmB) is a life-saving polyene antibiotic used to treat deep-seated mycotic infections. Both the mode of therapeutic action as well as toxic side effects are directly dependent on molecular organization of the drug. Binding of AmB to lipid monolayers formed with dipalmitoylphosphatidylcholine, pure and containing 40 mol% cholesterol or ergosterol, the sterols of human and fungi respectively, has been examined by means of

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“…In the latter case, AmB is postulated to self-aggregate into the hydrophilic pores that may severely affect transmembrane ion transport [8][9][10]. On the other hand, the results of the recent structural studies show that the pharmacological effect of AmB towards the membranes may be associated with modification of structural and dynamic properties of the lipid bilayer [11][12][13][14]. Despite the exact mode of action of AmB it is without doubt that both the pharmacological activity and the toxic side effects are strongly dependent on molecular organization of the drug in formulation [1,[15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Anomalously high aggregation level of the polyene antibiotic amphotericin B in acidic medium: Implications for the biological action

Gagoś

Hereć²,

Arczewska³

et al. 2008

Biophysical Chemistry

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Amphotericin B (AmB) is a polyene antibiotic used to treat deep-seated mycoses. Both the therapeutic action and the toxic side effects of this drug are dependent on its molecular organization. AmB appears as a zwitterion at neutral pH owing to -NH 3 + and -COO -groups.The results obtained with electronic absorption, fluorescence, resonance light scattering and infrared absorption spectroscopic analyses show that in the aqueous medium at pH above 10 AmB appears in the monomeric form owing to the negative net electric charge of the molecule. On the contrary, anomalously high aggregation level has been observed at pH below 2, despite the positive net electric charge. The effect is interpreted in terms of the permanent polarization of the polyene chain at low pH, associated with relative rotational freedom of the charged mycosamine fragment of the molecule. The pH-dependent aggregation of AmB is discussed in aspect of pharmacological action of the drug.

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The chain conformational order of ergosterol- or cholesterol-containing DPPC bilayers as modulated by Amphotericin B: a FTIR study

Cited by 41 publications

References 52 publications

Celecoxib-loaded liposomes: effect of cholesterol on encapsulation and in vitro release characteristics

Celecoxib-loaded liposomes: effect of cholesterol on encapsulation and in vitro release characteristics

Molecular organization of antifungal antibiotic amphotericin B in lipid monolayers studied by means of Fluorescence Lifetime Imaging Microscopy

Anomalously high aggregation level of the polyene antibiotic amphotericin B in acidic medium: Implications for the biological action

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