Cyclodextrin and polysaccharide-based nanogels: entrapment of two hydrophobic molecules, benzophenone and tamoxifen

The entrapment of two hydrophobic molecules, benzophenone and tamoxifen, into self-assembling cyclodextrin (CD)-based nanogels has been studied. These nanogels formed spontaneously upon the association of a hydrophobically modified dextran (MD) and a cyclodextrin polymer (pbetaCD). The interactions of benzophenone and tamoxifen with MD and pbetaCD were investigated using phase solubility studies, circular dichroism, and isothermal titration calorimetry. Both hydrophobic molecules were included into the CD cavities of the pbetaCD and were also solubilized by MD into its hydrophobic microdomains. We took advantage of these interactions to form benzophenone- and tamoxifen-loaded nanogels. The highest benzophenone loadings were obtained by solubilizing it in both pbetaCD and MD solutions before mixing them to form nanogels. These studies open new possibilities of applications of the nanogels, mainly in the cosmetic field, as sun screen carriers prepared by a simple "green" technology.