Bioactive Biomolecules Interacting with Cellular Membranes: Modelling with Langmuir Monolayers

Cell membranes are essential for life, since they compartmentalize cells, the basic unit of living matter, and mediate their symbiosis with the environment. In many events in which cells participate, interaction with biomolecules such as polysaccharides, proteins and peptides, is crucial. In spite of the developments in physics, chemistry and biology in the last century, the study of cells and bioactive biomolecules interacting "in vivo" is still elusive. Therefore, simplified models are employed to obtain fundamental knowledge from these systems. In this chapter, the use of Langmuir monolayers as cell membrane models made to interact with biomolecules is described. Firstly, a brief introduction on the nature of nanostructured Langmuir monolayers is provided. In particular, we describe technical aspects related to the experimental setup and procedures to guide novice researchers in the field. We also describe the fundamentals and possibilities of the most useful techniques applied to film characterization. In the final section, examples are given of Langmuir monolayers successfully employed to obtain relevant molecular-level information from systems involving biomolecules. Trends in the field are discussed as motivation for innovative research to bridge the gap between biology (and medicine) and the physicochemical framework used in cell membrane modeling.