Learning from plant cell walls as a path for innovations in food and material sciences

The research will dissect the structural factors controlling cell walls and cell communication for two main purposes: to improve the health value of food crops and to design strategies for the valorisation of wasted plant materials. The research is inspired by a recent paper from the primary supervisor which described interactions between the cell wall polysaccharides cellulose and callose (beta-1,3 glucans) leading to novel properties in hydrogels biopolymer mixtures (Abou-Saleh et al., Nat Comm. 2018). Changes in beta-1,3 glucans composition are reported in response to environmental stress conditions and to mechanical handling post-harvest. On the other hand, beta-1,3 glucans have been used to lower cholesterol, reduce diabetes and to improve the immune system. The project will expand and exploit this knowledge by quantifying the levels of beta-1,3 glucans pre- and post-harvest in food crops using highly specific molecular probes. Correlation will be established between beta-1,3 glucan composition and the structural-mechanical properties of cell walls in these food crops using multiple techniques such as electron-microscopy and Instrons/ AFM based methods. The effect of beta-1,3 glucans in human health will be evaluated using different cell reporter models to monitor gene expression profiles in mammalian cells. The results will guide the development of new materials from wasted plant/food resources. Cellulose-based materials are used for tissue engineering, wound-dressing, drug delivery and/or other biomedical applications. Beta 1,3 glucans can improve cellulose biodegradability and, as described above, have additional health benefits. During the project, different plant materials will be evaluated as potential sustainable sources for isolation of these polysaccharides. The student will determine the biodegradability, immunoreactivity, biocompatibility, allergenicity and, more critically, mechanical and biological stability during handling and storage of cellulose-beta-1,3 glucan gel mixtures made from commercial standards and extracted from plant material. Their capacity for drug absorption and reactivity will be determined to support the development of new drugs and more switchable patterns for their release (according to needs). As part of the PhD, new sensors will be developed for the detection of beta 1,3 glucans in crops and correlations established with mechanical and health properties of food produce. In parallel a range of novel plant-derived beta-1,3 glucan-rich hydrogels materials will be characterized from a structural, biological and physico-mechanical perspective aiming to identify new applications for plant resources in a biomedical context. In this way the work addresses global challenges on food security, sustainable health and wellbeing, environmentally sustainable production of materials and valorisation of natural resources.