Microbial glycolipid biosurfactants: from self-assembly to hydrogel and emulsion development

Ghazi Ben Messaoud, Sophie LKW Roelants, Wim Soetaert, Chris V. Stevens

Sorbonne Université, France; Bio Base Europe Pilot Plant; Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Ghent University; University of Ghent

Soft self-assembled materials (hydrogels, coacervates…) are applied in many fields, from thickeners, to drug encapsulation, wound healing, etc… Microbial glycolipid biosurfactants, obtained from the fermentation of renewable resources and interesting for their biodegradability and low cytotoxicity, may constitute a new class of soft materials. However, their self-assembly properties are still poorly known [1,2] and their applications in the field of soft matter practically not existing.
This contribution discusses the self-assembly properties of selected microbial glycolipid biosurfactants and the recent development of soft materials. We show that microbial glycolipid biosurfactants can form self-assembled micelles, fibers and bilayers, that can then be used to form hydrogels in water [3], coacervates [4] or emulsions, the properties of which will in turn depend on pH and temperature. The self-assembly will be shown via SAXS and cryo-TEM experiments, while the gelling properties will be analyzed using time, temperature and pH-resolved rheology experiments.
This presentation provides a new insight in terms of understanding the complexity of the physico-chemical behaviour of microbial glycolipid biosurfactants but it also shows that understanding their properties allows their use in the preparation of soft materials.

1 A.-S. Cuvier, N. Baccile et al. Soft Matter, 2014, 10, 3950
2 N. Baccile et al. Langmuir, 2016, 32, 6343
3 N. Baccile et al. Soft Matter, 2018, 14, 7859
4 G. Ben Messaoud et al. Green Chemistry, 2018, 20, 3371