Mixing behavior of binary insoluble phospholipid monolayers. analysis of the mixing properties of binary lecithin and cephalin systems by application of several surface and spreading techniques

Dörfler, H.‐D.

doi:10.1016/0001-8686(90)80003-i

Cited by 51 publications

(55 citation statements)

References 57 publications

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“…The excess areas of mixing A E which provides a measure of non-ideality, were calculated as a function of surface pressure, mixture of composition and the molecular weight using the additivity rule [11][12][13] A E = A 12 -A av ……………….. The experimental data in case of both PMMA and SA matrices almost coincide with the ideality curve.…”

Section: Resultsmentioning

confidence: 99%

Spectroscopic characterizations of the mixed Langmuir–Blodgett (LB) films of 2,2′-biquinoline molecules: Evidence of dimer formation

Deb¹,

Biswas²,

Hussain³

et al. 2005

Chemical Physics Letters

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Section: Resultsmentioning

confidence: 99%

Spectroscopic characterizations of the mixed Langmuir–Blodgett (LB) films of 2,2′-biquinoline molecules: Evidence of dimer formation

Deb¹,

Biswas²,

Hussain³

et al. 2005

Chemical Physics Letters

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“…The concentration dependence of the breakpoint(s) of the phase transition of the compression isotherms was used as a criterion for the miscibility of binary mixtures at the air-water interface (16,21,23,31,32). In short, a concentration-dependent phase transition is indicative of complete miscibility of the components, whereas concentration independence is a sign of immiscibility of the components (31).…”

Section: Interaction Of Nicotinates With Dppc At the Air-water Interfacementioning

confidence: 99%

“…In short, a concentration-dependent phase transition is indicative of complete miscibility of the components, whereas concentration independence is a sign of immiscibility of the components (31). Because of experimental limitations, the collapse pressure of the compression isotherms of most mixtures was not recorded and, therefore, was not used to assess the miscibility of the mixed films.…”

Section: Interaction Of Nicotinates With Dppc At the Air-water Interfacementioning

confidence: 99%

Interaction of long-chain nicotinates with dipalmitoylphosphatidylcholine

Lehmler

Fortis-Santiago

Nauduri

et al. 2005

Journal of Lipid Research

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The interaction of four long-chain nicotinates, compounds that are of interest as potential chemopreventive agents, with dipalmitoylphosphatidylcholine (DPPC) was investigated in monolayers at the air-water interface and in fully hydrated bilayers. For the monolayer studies, the compression isotherms of mixtures of the respective nicotinate with DPPC were recorded at various compositions on a hydrochloric acid subphase (pH 1.9-2.1, 37 ؎ 2 ؇ C). The headgroup of the nicotinates (24-29 Å 2 /molecule) is larger than that of the hydrophobic tail (20 Å 2 /molecule). The pure nicotinates exhibit a temperature-and chain lengthdependent transition from an expanded to a condensed phase. Analysis of the concentration dependence of the average molecular area at constant film pressure and the concentration dependence of the breakpoint of the phase transition from the expanded to the condensed state suggests that all four DPPC-nicotinate mixtures are partially miscible at the air-water interface. Although a complex phase behavior with several phase transitions was observed, differential scanning calorimetry studies of the four mixtures are also indicative of the partial miscibility of DPPC and the respective nicotinate.Overall, the complex phase behavior most likely results from the head-tail mismatch of the nicotinates and the geometric packing constraints in the twocomponent lipid bilayer. Nicotinic acid and its alkyl esters are of considerable biological and pharmacological importance. Besides being the precursor of cofactors to many vital enzymes, nicotinic acid is a drug possessing vasodilating and fibrinolytic properties. Nicotinic acid itself has been proven beneficial against bleomycin-and cyclophosphamide-induced lung injury in animal models (1-5). Dietary supplements of nicotinic acid and dermatologic formulations of its longchain esters are under investigation for the prevention and treatment of skin carcinogenesis (6). Therefore, nicotinic acid esters may be useful as a chemopreventive agent for the prevention of lung cancer.Currently, there is significant interest in the pulmonary administration of several chemopreventive agents, such as steroids and retinoids, directly to the lung because of reduced systemic toxicity (7-11). This route of administration may also be advantageous for the administration of nicotinic acid esters, by using either an aerosol or a perfluorocarbon vehicle (12, 13). Although the interaction of various chemopreventive agents, especially retinoids, with phospholipids has been investigated (14, 15), there is no current knowledge about the factors that determine the interaction (i.e., phase behavior) of nicotinates with biological lipids such as the phospholipids present in pulmonary surfactant. A better understanding of these interactions, however, is a prerequisite for the rational design of nicotinates for pulmonary administration, especially using a perfluorocarbon-based drug delivery system (12, 13). The aim of this study is to understand which molecular characteristics influe...

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“…In short, a composition-dependent phase transition onset is evidence of the complete miscibility of the components, whereas composition independence is a sign of immiscibility of the components (29). As a second criterion, the composition dependence of the average molecular area at constant film pressure may be used to assess the miscibility of two components at the air-water interface (17-19, 29, 30).…”

Section: Interaction At the Air-water Interfacementioning

confidence: 99%

Interaction of a partially fluorinated long-chain nicotinate with dipalmitoylphosphatidylcholine

Lehmler

Bummer

2005

Journal of Lipid Research

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The interaction of a partially fluorinated longchain nicotinate, F-NA18, a compound of interest as a chemopreventive agent, with dipalmitoylphosphatidylcholine (DPPC) was investigated in monolayers at the air-water interface and in fully hydrated bilayers and compared with its hydrocarbon analog, NA18. For the monolayer studies, the compression isotherms of mixtures of F-NA18 with DPPC were recorded at various compositions on a hydrochloric acid subphase (pH ‫؍‬ 1.9-2.1, 32 ؎ 2 ؇ C). Analysis of the composition dependence of the average molecular area at constant film pressure and of the dependence of the breakpoints of the phase transitions suggests that F-NA18 is miscible with DPPC at the airwater interface, whereas NA18 shows some degree of immiscibility. In differential scanning calorimetry studies, only one major phase transition was observed for F-NA18-DPPC mixtures, whereas NA18-DPPC mixtures exhibited a complex phase behavior. The differences in the phase behavior of the respective mixtures may be the result of the geometric packing constraints of F-NA18 versus NA18. Therefore, for biomedical applications, the use of a partially fluorinated tail may offer advantages over simple hydrocarbon systems because, in addition to the chain length, the position and degree of fluorination can be adjusted.

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Mixing behavior of binary insoluble phospholipid monolayers. analysis of the mixing properties of binary lecithin and cephalin systems by application of several surface and spreading techniques

Cited by 51 publications

References 57 publications

Spectroscopic characterizations of the mixed Langmuir–Blodgett (LB) films of 2,2′-biquinoline molecules: Evidence of dimer formation

Spectroscopic characterizations of the mixed Langmuir–Blodgett (LB) films of 2,2′-biquinoline molecules: Evidence of dimer formation

Interaction of long-chain nicotinates with dipalmitoylphosphatidylcholine

Interaction of a partially fluorinated long-chain nicotinate with dipalmitoylphosphatidylcholine

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