Langmuir-Blodgett films of amphiphilic cyclodextrins

Synthesis and characterisation of O-6-alkylthio- and perfluoroalkylpropanethio-α-cyclodextrins and their O-2-, O-3-methylated analogues

“…The stability of these monolayers, as determined by the collapse pressure (p c ), is in the range of 27-29 mN m À1 and increases very slightly with the chain length (1 mN m À1 per -CH 2 -CH 2 ). The above results can be compared to the values found for hexakis[6-deoxy-6-(S-hexadecanethio)]-a-cyclodextrin, 28 which are 173 A ˚2 per molecule for the A 0 value and 60 mN m À1 for p c . The decrease of p c can be explained by weaker interactions between 9a, 9b and 9c and the aqueous subphase, due to the higher polarity of the hydroxyl group as compared to the methoxy group.…”

Nano-Assemblies of Modified Cyclodextrins and Their Complexes with Guest Molecules: Incorporation in Nanostructured Membranes and Amphiphile Nanoarchitectonics Design

“…Di- and polysubstituted amphiphilic cyclodextrins have been obtained by grafting of aliphatic chains or cholesteryl moieties on the primary hydroxyl groups of the cyclodextrin rim via amine, sulphur or sulfoxide linkers [ 13 , 14 , 15 , 16 , 53 , 54 ]. Studies of the interfacial properties of these compounds have shown that they may form stable monomolecular layers at the air-water interface [ 13 , 14 , 15 , 16 ]. For alkyl chain lengths longer than eight carbon atoms (C 8 ), the monolayer transfer from the air/water interface to a solid support has yielded Langmuir-Blodgett multilayer films [ 15 ].…”

“…In general, high hydrophobicity of the cyclodextrin derivatives might constitute an obstacle for their inclusion in lipid bilayer membranes owing to the preference for phase separation in two-dimensional domains. A variety of physical and physico-chemical methods (small-angle X-ray scattering (SAXS), X-ray diffraction, small-angle neutron scattering (SANS), X-ray-reflectivity, neutron reflectivity, differential scanning calorimetry (DSC), deuterium nuclear magnetic resonance ( 2 H NMR), surface pressure/area isotherms, Brewster angle microscopy (BAM), atomic force microscopy (AFM), cryogenic transmission electron microscopy (cryo-TEM), and confocal laser scanning microscopy (CLSM)) have been employed to investigate these effects [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 …”

“…Grafting of hydrophobic moieties on the primary or the secondary faces of natural cyclodextrins (cyclic oligosaccharides forming nanocavity structures) confers them an amphiphilic character [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. Synthesis of various modified cyclodextrins has been undertaken because such amphiphilic compounds may self-organize in aqueous phase to form supramolecular assemblies as drug carriers of high stability upon dilution [ 22 , 23 , 24 , 25 , 26 , 27 , 28 ].…”

Monomolecular Layer Formation of Amphiphilic Chromoionophore I at the Air/Water Interface

“…Kawabata et al reported the effect of hydrophobic chain length on the formation of stable condensed monolayers using cyclodextrin (CD) derivatives and concluded that CD derivatives with alkyl chains of more than eight carbon atoms were needed to form stable monolayers at the air/water interface. 20 In this study, we explored the monolayer formation of chromoionophore I having a similar projection area of bulky domain to the CD derivatives at the air/water interface, changing various experimental conditions such as the subphase pH and the relaxation time after spreading the solution. We discuss the packing of chromoionophore I by the hydrophobic interaction of alkyl chains and benzo[a]phenoxazine moieties.…”