The plant cell wall (PCW) is a multidimensional structure composed of a cellulose microfibril net embedded in a soluble matrix of pectic polysaccharides, hemicelluloses, and a small proportion of glycoproteins, phenolic components and ions ¹. Understanding the contribution of cell wall components to the mechanical and biological properties of cell walls as a whole is challenging, due to the heterogeneity of plant tissues/organs and the ability of plants to adapt and modify cell wall composition in response to environmental stimuli ².

Different approaches have been developed to study the mechanics of the cell wall or the interaction between polysaccharides. For example: Atomic Force microscopy or Brillouin scattering. These methods are difficult to set-up, rely in highly qualified experts and expensive equipment which can limit their routine application in regular labs. Therefore, in this publication a method is presented to analyse the properties and interactions of PCW individual components by mimicking the cell wall tri-dimensional matrix using a simplified model of composite macro-hydrogels & alcogels and a texture analyser. The analysis of cellulose-xylan hydrogels using a Texture Analyser will be reported for first time here. The results confirm the applicability of this method in the screening of interactions between cell walls polymers. We also applied the method to study the properties of cellulose extracted from tomato as these are unused products in the food industry. Results are compared and correlated with material composition offering a new approach for the screening of agricultural waste available for exploitation in new materials.

Unravel the mechanical properties of the cell wall and/or individual cell wall glycans is now a priority, in order to act in advance to the imminent global change and look for new bio-degradable low cost materials derived from renewable sources that can be used as an alternative to environmentally hazardous plastic. Additionally, texture analysis of the cell wall polysaccharides could be relevant for other disciplines as a food industry ³ or medical engineering to develop scaffolds ⁴or drug delivery ⁵.

References:

1. Jamet, E. & Dunand, C. Plant Cell Wall Proteins and Development. Int J Mol Sci21, doi:10.3390/ijms21082731 (2020).
2. Lopez-Sanchez, P.et al. Cellulose-pectin composite hydrogels: Intermolecular interactions and material properties depend on order of assembly. Carbohydr Polym 162, 71-81, doi:10.1016/j.carbpol.2017.01.049 (2017).
3. Riaz, A.et al. Preparation and characterization of chitosan-based antimicrobial active food packaging film incorporated with apple peel polyphenols. Int J Biol Macromol 114, 547-555, doi:10.1016/j.ijbiomac.2018.03.126 (2018).
4. Gershlak, J. R.et al. Crossing kingdoms: Using decellularized plants as perfusable tissue engineering scaffolds. Biomaterials 125, 13-22, doi:10.1016/j.biomaterials.2017.02.011 (2017).
5. Xiao, Y.et al. Low cost delivery of proteins bioencapsulated in plant cells to human non-immune or immune modulatory cells. Biomaterials 80, 68-79, doi:10.1016/j.biomaterials.2015.11.051 (2016).