E-mail: joonsig@cnu.ac.krReceived July 3, 2013, Accepted July 25, 2013Diacetylene lipid monomers possess the capability to self-assemble into vesicles via polymerization underultraviolet irradiation, resulting in the formation of polydiacetylene (PDA) liposomes. Exposure of the poly-merized vesicles to external stimuli is known to induce a unique blue-to-red color transition. The cyclicoligosaccharide α-cyclodextrin known for its use in many applications, such as drug delivery, purification, andstimulus sensing, is able to form an inclusion complex with poly(ethylene glycol) (PEG) in aqueous solution.In this study, we prepared polymeric liposomes with PEG (PEG-PDA) with the aim of improving the stabilityof the vesicles and colorimetric response toward α-cyclodextrin. We demonstrated that PEG-PDA liposomedisplays unique characteristics compared with native PDA liposome and it also shows apparent chromicproperties of the inclusion complex formation with α-cyclodextrin.Key Words : Polydiacetylene, Liposome, Self-inclusion complex, α-Cyclodextrin, Poly(ethylene glycol)IntroductionNon-covalent bonds, which are crucial intermolecularforces involved in the assembly of supramolecular complexes,are generally based on host-guest interactions. These forcesare involved in maintaining three-dimensional structures ofmacromolecules via hydrogen bonding, electrostatic forces,hydrophobic interactions, and van der Waals interactions.Owing to its structural properties, cyclodextrin continues tobe one of the most studied host molecules, and has foundapplication in various fields such as drug delivery