282
proposed uses in food science, and, more recently, smart packaging using cyclodextrin polymers is being developed. In the case of the pharmaceutical and biomedical
applications, numerous studies on cyclodextrin polymers are being published in the
last years, mainly in drug release, but also as polymeric vectors for gene delivery as
well as in the field of regenerative medicine.
Keywords History · Cyclodextrin polymers · Covalent networks · Food ·
Pharmacy · Drug delivery · Inclusion complexes
6.1 Introduction
In addition to their remarkable capability to establish supramolecular (host-guest)
interactions by themselves because of their toroidal shape and nonpolar inside,
cyclodextrins can also be covalently attached in different ways to originate more
complex structures. Materials containing more than two covalently linked cyclodextrin units are known as cyclodextrin polymers. The three procedures to produce
these materials are the attachment of cyclodextrins (or their derivatives) to a preexisting polymer by grafting reactions, the cross-linking of cyclodextrins by polycondensation using multifunctional reagents, and the polymerization of cyclodextrin
derivative monomers. The examples of the latter procedure are scarce in comparison
with the cross-linking and grafting cases.
This chapter will cover, from a historical point of view, the synthesis and characterization of such cyclodextrin derivatives. After these new materials have been introduced, the following section will be devoted to their applications both in food
chemistry and pharmaceutics and biomedicine. It needs to be mentioned that, in contrast to the enormous amount of studies on the uses of cyclodextrins in these two
sectors (see Fig. 6.1), cyclodextrin polymer references are not as abundant. As a
matter of fact, we will show that most of the examples found in the literature correspond to the last 10–15 years.
There are several reasons to produce cyclodextrin polymers in order to achieve
new potential applications in these areas. For instance, in the case of drug delivery,
which is by far the most frequently investigated subject among the biomedical
applications, the complexation capabilities of cyclodextrins and the controlled
release rate of the guest drugs can be modulated with the aid of the additional functionality of a polymeric macrostructure. In other cases, the covalent attachment of
cyclodextrin moieties to a pre-existing structure is intended to immobilize them, as
in the case of medical devices or packaging applications.
According to the previous definition of cyclodextrin polymers, this chapter will
deal with those materials in which at least three cyclodextrin units are covalently
attached either with each other or to a pre-existing polymer. Thus, we will not cover
the functionalization of non-polymeric supports such as silica beads or inorganic
nanoparticles (i.e., cyclodextrin nanocomposites). Amphiphilic cyclodextrins and
star polymers with a cyclodextrin core are also very interesting macromolecular
derivatives, produced by making use of the multiple hydroxyl groups that can be
M. Petitjean et al.
proposed uses in food science, and, more recently, smart packaging using cyclodextrin polymers is being developed. In the case of the pharmaceutical and biomedical
applications, numerous studies on cyclodextrin polymers are being published in the
last years, mainly in drug release, but also as polymeric vectors for gene delivery as
well as in the field of regenerative medicine.
Keywords History · Cyclodextrin polymers · Covalent networks · Food ·
Pharmacy · Drug delivery · Inclusion complexes
6.1 Introduction
In addition to their remarkable capability to establish supramolecular (host-guest)
interactions by themselves because of their toroidal shape and nonpolar inside,
cyclodextrins can also be covalently attached in different ways to originate more
complex structures. Materials containing more than two covalently linked cyclodextrin units are known as cyclodextrin polymers. The three procedures to produce
these materials are the attachment of cyclodextrins (or their derivatives) to a preexisting polymer by grafting reactions, the cross-linking of cyclodextrins by polycondensation using multifunctional reagents, and the polymerization of cyclodextrin
derivative monomers. The examples of the latter procedure are scarce in comparison
with the cross-linking and grafting cases.
This chapter will cover, from a historical point of view, the synthesis and characterization of such cyclodextrin derivatives. After these new materials have been introduced, the following section will be devoted to their applications both in food
chemistry and pharmaceutics and biomedicine. It needs to be mentioned that, in contrast to the enormous amount of studies on the uses of cyclodextrins in these two
sectors (see Fig. 6.1), cyclodextrin polymer references are not as abundant. As a
matter of fact, we will show that most of the examples found in the literature correspond to the last 10–15 years.
There are several reasons to produce cyclodextrin polymers in order to achieve
new potential applications in these areas. For instance, in the case of drug delivery,
which is by far the most frequently investigated subject among the biomedical
applications, the complexation capabilities of cyclodextrins and the controlled
release rate of the guest drugs can be modulated with the aid of the additional functionality of a polymeric macrostructure. In other cases, the covalent attachment of
cyclodextrin moieties to a pre-existing structure is intended to immobilize them, as
in the case of medical devices or packaging applications.
According to the previous definition of cyclodextrin polymers, this chapter will
deal with those materials in which at least three cyclodextrin units are covalently
attached either with each other or to a pre-existing polymer. Thus, we will not cover
the functionalization of non-polymeric supports such as silica beads or inorganic
nanoparticles (i.e., cyclodextrin nanocomposites). Amphiphilic cyclodextrins and
star polymers with a cyclodextrin core are also very interesting macromolecular
derivatives, produced by making use of the multiple hydroxyl groups that can be
M. Petitjean et al.