Probing the multiscale structure, composition and nanomechanical properties of lipids and biopolymers in natural systems: a few examples

Abstract

The natural systems as plants or animal tissues possess a highly complex organisation of numerous components: micronutriments, proteins, polyssacharides, lipids, water, …. Their natural arrangement gives very fine structures that range from the nanometer up to few meters scale range (typically from the protein to the whole plant). Native architectures have a direct influence on the functional, chemical, organoleptic and nutritional macroscopic properties relevant for designing sustainable performant products for environmentally compatible food and non–food uses. The development and application of experimental methodologies to probe the assemblies of lipids, biopolymers, mineral nutrients as well as structural water from the sub‐cellular to the molecular levels is then a permanent challenge. The parallel use of a set of complementary microscopy tools that provides relevant information may be needed to overcome the complexity of hydrated natural systems and to get both their structural, composition and nanomechanical properties. Most of the time, the experimental sample preparation is also a critical prerequisite to adapt the biological samples to the features of the analytical tool while keeping as most as possible the structures in their native shape. Thanks to this step, the microscopy tools can be operated through a direct or indirect correlation approach. Using few applications we developed on biopolymer‐based nanoparticles as well as animal cells or plant tissues (see Figure 1), we will show how to probe the structure/composition/nanomechanical properties focusing on the strong complementarity of AFM imaging and force mapping, Raman mapping, SEM/EDX, and scanning transmission X‐ray spectrometry (STXM). We will also discuss about the samples preparation strategies, and about data processing in relation to the information expected.