Cyclodextrin-containing layer-by-layer films and microcapsules: Synthesis and applications

This article reviews the synthesis and applications of cyclodextrin (CD)-containing layer-by-layer (LbL) films and microcapsules. CD-containing LbL films and microcapsules have been synthesized through the electrostatic interactions between charged CDs and polyelectrolytes or the formation of host-guest complexes. In the former strategy, sulfonated and carboxylated CDs are often combined with oppositely charged polyelectrolytes. In contrast, in the latter strategy, CD-bearing polymers and guest-modified polymers are used as components of LbL assembly. Typical guest molecules include adamantane, ferrocene, and azobenzene derivatives. Electrochemical biosensors have been constructed by coating the surface of electrodes with CD-containing LbL films. In addition, CD-containing LbL assemblies are used as scaffolds for constructing drug delivery systems, in which hydrophobic, poorly soluble drugs are loaded on the film through host-guest complexation.