  Cyclodextrins (CD) are a family of oligosaccharides with a toroid shape,
which exhibit a remarkable ability to include guest molecules in their internal
cavity providing a hydrophobic environment for poorly soluble molecules.
Recently new types of inclusions of alpha CD with alkyl grafted polysaccharide
chains (pullulan, chitosan, dextran, amylopectin, chondroitin sulfate) have
been prepared which are auto assembled into micro and nano platelets. We report
in this paper an extensive investigation of platelets with different
compositions, including their reversible hydration (Thermo Gravimetric
Analysis), crystalline structure (Powder X Rays Diffraction), dimensions and
shapes, (Scanning Electron Microscopy Field Emission Gun), thermal properties,
solubility and melting (Micro Differential Scanning Calorimetry). The
crystalline platelets exhibit layered structures intercalating the
polysaccharide backbones and CD complexes hosting the grafted alkyl chains. The
monoclinic symmetry of columnar type crystals suggests a head to tail
arrangement of the CDs. The platelets have a preferentially hexagonal shape
with sharp edges, variable sizes, and thicknesses and sometimes show incomplete
layers (terraces). The crystal parameters change upon dehydration. Melting
temperatures of platelets in aqueous solutions exceeds 100 degree. Finally, we
discuss the potential relation between the platelet structure and applications
for mucoadhesive devices.
