325
cyclodextrin via an oil/water hot homogenization method for colon-specific drug
delivery. In vitro and ex vivo investigations confirmed solid lipid nanoparticles as
a prominent carrier for colonic drug delivery. Additionally, in vitro toxicity studies showed that the solid lipid nanoparticles are well tolerated. Furthermore, Baek
and Cho (2013) developed the surface-modified paclitaxel-filled solid lipid
nanoparticles with hydroxypropyl-β-cyclodextrin. This cyclodextrin has been recognized to solubilize the drugs and inhibit the oxidation of lipids (Zafar et al.
2013). The formulated solid lipid nanoparticles showed a paclitaxel encapsulation
percentage of 71% with a mean size of 251 nm. The Caco-2 cell uptake of paclitaxel from solid lipid nanoparticles was 5.3-fold greater than the Taxol
formulation.
Nanostructured lipid carriers represent an upgraded generation of lipid nanoparticle, which overcome the major drawback of solid lipid nanoparticles, particularly
the tendency of discharge of the drug during storage as an outcome of their highly
ordered crystalline composition. Nanostructured lipid carriers composed by a solid
lipid matrix are developed from a mixture of biocompatible solid and liquid lipids
and an aqueous phase containing a surfactant or a blend of surfactants. Recently,
several reports have been published demonstrating the strategy of simultaneously
utilizing the advantages of both cyclodextrin and nanolipid carriers by locking them
in a novel drug delivery system, by incorporating the drug-cyclodextrin inclusion
complex into the lipid nanoparticles. A brief summary of recently developed
cyclodextrin- based solid lipid nanoparticles and lipid nanoparticles loaded with
various drugs used as anticancer, antihypertensive, diuretic, and anti-inflammatory
is illustrated in Table 7.2.
7.7 Role of Cyclodextrin in Gold and Silver Nanoparticles
In recent years, gold and silver nanoparticles have been widely investigated for
nanomedicine due to their superior optical, chemical, and biological properties
which make them ideal for molecular imaging, drug/gene delivery, biosensors, and
therapeutic agents. Furthermore, silver nanoparticles have antibacterial properties
that make them desirable for drug delivery systems as they provide additional antimicrobial action. When combined with cyclodextrins, these metallic nanoparticles
can become more targeted. Gold and silver cyclodextrin nanoparticles are commonly produced by connecting cyclodextrin to the metallic core using a linker, such
as adamantane, which forms a strong stable complex with the cyclodextrins
(Fig. 7.2). Sometimes the cyclodextrins are added by using cyclodextrin-loaded
macromolecules (cyclodextrin-modified hyaluronic acid).
Liu et al. (1998) first developed a novel technique for the surface derivatization
of gold colloidal particles to prepare gold colloidal particles of diameter > 10 nm.
They demonstrated aqueous solubilization of aliphatic thiols by α-cyclodextrin,
which effectively binds to the aliphatic chains and carries the hydrophobic thiol
7 Role of Cyclodextrins in Nanoparticle-Based Systems for Drug Delivery
cyclodextrin via an oil/water hot homogenization method for colon-specific drug
delivery. In vitro and ex vivo investigations confirmed solid lipid nanoparticles as
a prominent carrier for colonic drug delivery. Additionally, in vitro toxicity studies showed that the solid lipid nanoparticles are well tolerated. Furthermore, Baek
and Cho (2013) developed the surface-modified paclitaxel-filled solid lipid
nanoparticles with hydroxypropyl-β-cyclodextrin. This cyclodextrin has been recognized to solubilize the drugs and inhibit the oxidation of lipids (Zafar et al.
2013). The formulated solid lipid nanoparticles showed a paclitaxel encapsulation
percentage of 71% with a mean size of 251 nm. The Caco-2 cell uptake of paclitaxel from solid lipid nanoparticles was 5.3-fold greater than the Taxol
formulation.
Nanostructured lipid carriers represent an upgraded generation of lipid nanoparticle, which overcome the major drawback of solid lipid nanoparticles, particularly
the tendency of discharge of the drug during storage as an outcome of their highly
ordered crystalline composition. Nanostructured lipid carriers composed by a solid
lipid matrix are developed from a mixture of biocompatible solid and liquid lipids
and an aqueous phase containing a surfactant or a blend of surfactants. Recently,
several reports have been published demonstrating the strategy of simultaneously
utilizing the advantages of both cyclodextrin and nanolipid carriers by locking them
in a novel drug delivery system, by incorporating the drug-cyclodextrin inclusion
complex into the lipid nanoparticles. A brief summary of recently developed
cyclodextrin- based solid lipid nanoparticles and lipid nanoparticles loaded with
various drugs used as anticancer, antihypertensive, diuretic, and anti-inflammatory
is illustrated in Table 7.2.
7.7 Role of Cyclodextrin in Gold and Silver Nanoparticles
In recent years, gold and silver nanoparticles have been widely investigated for
nanomedicine due to their superior optical, chemical, and biological properties
which make them ideal for molecular imaging, drug/gene delivery, biosensors, and
therapeutic agents. Furthermore, silver nanoparticles have antibacterial properties
that make them desirable for drug delivery systems as they provide additional antimicrobial action. When combined with cyclodextrins, these metallic nanoparticles
can become more targeted. Gold and silver cyclodextrin nanoparticles are commonly produced by connecting cyclodextrin to the metallic core using a linker, such
as adamantane, which forms a strong stable complex with the cyclodextrins
(Fig. 7.2). Sometimes the cyclodextrins are added by using cyclodextrin-loaded
macromolecules (cyclodextrin-modified hyaluronic acid).
Liu et al. (1998) first developed a novel technique for the surface derivatization
of gold colloidal particles to prepare gold colloidal particles of diameter > 10 nm.
They demonstrated aqueous solubilization of aliphatic thiols by α-cyclodextrin,
which effectively binds to the aliphatic chains and carries the hydrophobic thiol
7 Role of Cyclodextrins in Nanoparticle-Based Systems for Drug Delivery