329
of β-cyclodextrin offered a microenvironment that produced a rapid absorption of
guanine and adenine leading to faster electrocatalysis.
7.8 Pharmaceutical Applications of Amphiphilic
Cyclodextrin Nanoparticles
The potential use of cyclodextrin in a biological system needs amphiphilic properties because natural cyclodextrin has relatively low solubility both in water and
organic solvents, thus limiting their uses in pharmaceutical formulations.
Amphiphilic or ionizable cyclodextrins can modify the rate or time of drug release
and bind to the surface membrane of cells that may be used for the enhancement of
drug absorption across biological barriers. Improvement of the interaction of cyclodextrins with hydrophobic drugs renders self-assembly capacity in aqueous solutions (Bilensoy and Hincal 2009). Amphiphilic cyclodextrins are obtained by
grafting of 6-C aliphatic chains linked with ester or/and amide groups of different
length on the primary/secondary face of the glucopyranose units (Duchêne et al.
1999a). The major advantage of amphiphilic cyclodextrins is their self-assembly
properties which are sufficient to form different nanosized carriers spontaneously
without the presence of surfactants. This superiority gives them amphiphilic properties resulting in the formation of supramolecular aggregates in the nanometer range
(Duchêne et al. 1999b).
According to the chemical structure of the amphiphilic cyclodextrin, different
carrier systems could be obtained such as solid lipid nanoparticles, bilayer vesicles,
liposomes, and nanoparticles (Donohue et al. 2002; Dubes et al. 2003). According
to the groups conjugated onto cyclodextrins, amphiphilic cyclodextrin-based systems can be classified as nonionic, cationic, and anionic materials (Zhang and Ma
2013). Amphiphilic cyclodextrins have been synthesized to overcome the drawbacks of natural cyclodextrins. In addition, they have the ability to form selfassembled nanoparticulate systems. Their unique properties can improve the drug
loading capacity, cellular interaction and tumoral penetration, drug release profiles,
and cytotoxicity of drug delivery systems. Skiba et al. (1996) synthesized an amphiphilic β-cyclodextrin-based nanosphere drug delivery system prepared by uniform
dispersion of an organic solution of modified β-cyclodextrin in the hydrophilic
phase with or without surfactant. A preliminary study for the effect of surfactant on
the size, physicochemical properties, and stability of the nanospheres was carried
out. Furthermore, in a similar study, the authors reported the synthesis and characterization of amphiphilic cyclodextrin-based new nanosphere drug delivery system
consisted of fatty acid chain of either 6 or 12 or 14 carbon atoms assembled at the
02 and 03 positions of the β-cyclodextrin molecule. Table 7.3 summarized the various potential pharmaceutical applications of amphiphilic cyclodextrin-based
nanoparticles such as anticancer, cholesterol-targeted, folate-targeted, and amphiphilic cyclodextrin nanoparticles for gene delivery.
7 Role of Cyclodextrins in Nanoparticle-Based Systems for Drug Delivery
of β-cyclodextrin offered a microenvironment that produced a rapid absorption of
guanine and adenine leading to faster electrocatalysis.
7.8 Pharmaceutical Applications of Amphiphilic
Cyclodextrin Nanoparticles
The potential use of cyclodextrin in a biological system needs amphiphilic properties because natural cyclodextrin has relatively low solubility both in water and
organic solvents, thus limiting their uses in pharmaceutical formulations.
Amphiphilic or ionizable cyclodextrins can modify the rate or time of drug release
and bind to the surface membrane of cells that may be used for the enhancement of
drug absorption across biological barriers. Improvement of the interaction of cyclodextrins with hydrophobic drugs renders self-assembly capacity in aqueous solutions (Bilensoy and Hincal 2009). Amphiphilic cyclodextrins are obtained by
grafting of 6-C aliphatic chains linked with ester or/and amide groups of different
length on the primary/secondary face of the glucopyranose units (Duchêne et al.
1999a). The major advantage of amphiphilic cyclodextrins is their self-assembly
properties which are sufficient to form different nanosized carriers spontaneously
without the presence of surfactants. This superiority gives them amphiphilic properties resulting in the formation of supramolecular aggregates in the nanometer range
(Duchêne et al. 1999b).
According to the chemical structure of the amphiphilic cyclodextrin, different
carrier systems could be obtained such as solid lipid nanoparticles, bilayer vesicles,
liposomes, and nanoparticles (Donohue et al. 2002; Dubes et al. 2003). According
to the groups conjugated onto cyclodextrins, amphiphilic cyclodextrin-based systems can be classified as nonionic, cationic, and anionic materials (Zhang and Ma
2013). Amphiphilic cyclodextrins have been synthesized to overcome the drawbacks of natural cyclodextrins. In addition, they have the ability to form selfassembled nanoparticulate systems. Their unique properties can improve the drug
loading capacity, cellular interaction and tumoral penetration, drug release profiles,
and cytotoxicity of drug delivery systems. Skiba et al. (1996) synthesized an amphiphilic β-cyclodextrin-based nanosphere drug delivery system prepared by uniform
dispersion of an organic solution of modified β-cyclodextrin in the hydrophilic
phase with or without surfactant. A preliminary study for the effect of surfactant on
the size, physicochemical properties, and stability of the nanospheres was carried
out. Furthermore, in a similar study, the authors reported the synthesis and characterization of amphiphilic cyclodextrin-based new nanosphere drug delivery system
consisted of fatty acid chain of either 6 or 12 or 14 carbon atoms assembled at the
02 and 03 positions of the β-cyclodextrin molecule. Table 7.3 summarized the various potential pharmaceutical applications of amphiphilic cyclodextrin-based
nanoparticles such as anticancer, cholesterol-targeted, folate-targeted, and amphiphilic cyclodextrin nanoparticles for gene delivery.
7 Role of Cyclodextrins in Nanoparticle-Based Systems for Drug Delivery