Strings, anisometric gels, and solutions in chemical and biological systems

This article presents a review of the works that are devoted to the formation of supramolecular anisotropic structures in a wide class of model solutions of homochiral compounds and biological fluids. Spontaneous formation of crystalline rigid strings takes place in the study solutions at low concentrations ($10^{-3}\mbox{-}10^{-2}$ M) and continues to the stage of solution solidification. This is preceded, as revealed by dynamic light scattering, by the formation of linear associates, isometric granules, and strings themselves, which strongly and nonmonotonously affect chiroptical properties and the IR and UV absorption in solutions. Strings and similar objects can be considered as model elements of intercellular switches. The described structure apparently characterizes many biological fluids.