title: Orientational behaviors of liquid crystals coupled to chitosan-disrupted phospholipid membranes at the aqueous-liquid crystal interface.
abstract: In this study, we investigated the orientational behavior of liquid crystals (LCs) which is associated with the chitosan-disrupted phospholipid membrane at the aqueous/LC interface. The optical response of LCs changed from dark to bright after the transfer of an aqueous solution of chitosan onto the LC interface decorated with self-assembled monolayers of a negatively charged phospholipid, dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DOPG). The chitosan-lipid interactions induced a rearrangement of the membrane, and thus, resulted in an orientational transition of LCs from a homeotropic to a planar state, thereby triggering a dark-to-bright shift in the optical response. We observed that LCs exhibited a bright-to-dark shift after an aqueous solution of lysozyme was transferred onto the chitosan-disrupted membrane, which implied that an enzymatic reaction between lysozyme and chitosan took place. We found that the addition of bovine serum album (BSA) induced a bright-to-dark change in the optical response; while LCs remained to appear bright after the transfer of chymotrypsin onto the aqueous/LC interface. We then further examined the interactions between other polyelectrolytes and phospholipid membranes.
authors.affiliation: Department of Chemistry, Gachon University, Seongnam-Si, Gyeonggi-Do, 461-701, Republic of Korea.
authors.forename: Dingdong
authors.initials: D
authors.lastname: Liu
authors.forename: Qiong-Zheng
authors.initials: QZ
authors.lastname: Hu
authors.forename: Chang-Hyun
authors.initials: CH
authors.lastname: Jang
mesh_terms: D000818:Animals; D002417:Cattle; D048271:Chitosan / Q000737:chemistry*; D002918:Chymotrypsin / Q000737:chemistry; D050866:Liquid Crystals / Q000737:chemistry*; D008567:Membranes, Artificial; D008859:Microscopy, Polarization; D009113:Muramidase / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity; D014867:Water / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D010715:Phosphatidylglycerols; D014867:Water; D012710:Serum Albumin, Bovine; C051388:1,2-dioleoyl-sn-glycero-3-phosphoglycerol; D048271:Chitosan; D009113:Muramidase; D002918:Chymotrypsin; C117608:alpha-chymotrypsin