Vesicle behavior: in search of explanations.

In this paper we will present a series of experiments in the general field of surfactant aggregates and, in particular, in vesicle chemistry, which have found no definitive explanation until now. These experiments concern vesicle self-reproduction (in particular, the so-called matrix effect); the interaction between vesicle and RNA, where RNA appears capable of discriminating between vesicles differing slightly in size; the fusion of oppositely charged vesicles, which brings about unexpected behavior of size distribution; and some aspects of local concentration inside vesicles, which still lack clarification in terms of local versus overall concentration. The theoretical and experimental implications of this not yet understood behavior will be discussed, emphasizing that progress in the field must face the difficulty of applying thermodynamics to these kinetically trapped systems, and the general difficulty of understanding how kinetic and thermodynamic factors interplay with each other.