Influence of Lyotropic Liquid Crystals on the Ability of Antibodies To Bind to Surface-Immobilized Antigens

Abstract

We report an experimental study of the influence of lyotropic liquid crystalline phases on the ability of antibodies to bind to protein antigens immobilized on surfaces when the antibodies are delivered and bind to the antigens from the lyotropic liquid crystals (LCs). The LCs were prepared from anionic amphiphiles (sodium decyl sulfate (SDeS), cesium pentadecafluorooctanoate (CsPFO), and potassium laurate (KL)), cationic amphiphiles (decylammonium chloride (DACl) and cetylpyridinium chloride (CPCl)), nonionic amphiphiles (Brij 30 and Triton X114), and the zwitterionic surfactant tetradecyldimethyl-amineoxide (C14AO). In addition, we investigated LCs prepared from the nonamphiphilic molecules disodium cromoglycate (DSCG) and the dye molecule Direct Blue 67. Antihuman IgGs conjugated with the fluorescent label fluorescein-isothiocyanate (FITC) were dissolved in 12 lyotropic LCs and then incubated with human IgG that was arrayed on surfaces. Fluoresence microscopy was used to image antihuman IgG that bound to the immobilized human IgG. From this survey of lyotropic LCs, we identified three LCs (DSCG, C14AO, and CPCL) that permitted antihuman IgG dissolved in the LC to recognize and bind to surface-bound human IgG. Antibody binding in the other LCs was prevented by a number of mechanisms, including denaturation of the IgG (anionic surfactants) as well as slow mass transport due to high viscosity of the LC phases (nonionic surfactants). Because the lyotropic LC formed from DSCG exhibited the highest birefringence and the lowest viscosity among the LCs formed from DSCG, C14AO, and CPCL, the binding of antibodies in DSCG-based LCs to virus-infected cells was also investigated. We found that the binding of antibodies to vesicular stomatitis virus (VSV) that was inoculated into human epitheloid cervical carcinoma cells was highly specific in the lyotropic LC prepared from DSCG.