AquaCat aims to design greener chemical processes by combining the use of lipase catalysis to that of aqueous biphasic reaction media with a specific view to the synthesis of poly(lactone) nanoparticles and sugar esters for pharmaceutical, cosmetical and chemical applications. A multidisciplinary approach encompassing physical chemistry and polymer science as well as industrial biotechnology, biocatalysis and enzyme technology will be followed to cover the various relevant scales. AquaCat will tailor the lipases microenvironment, design the reaction medium making lipase function as synthetic catalyst of confined organic substrates and identify the relevant parameters for industrial scale up of these processes. AquaCat will thus circumvent major problems in the current manufacturing processes making the use of organometallic catalysts, hazardous organic solvents, high energy consumption and multi-steps for nanoparticle elaboration obsolete. Lipases will be used to catalyze the ring-opening polymerization in nano-emulsions consisting of lactone nanodroplets dispersed in aqueous or aqueous-biphasic systems. The most innovative aspect of AquaCat is to directly synthesize the core-shell poly(lactone) in one step in water. The same principle will be applied to the synthesis of important specialty chemicals like sugar esters based on renewable feedstock. A trademark of this project will thus be the possibility to transfer and merge the expert’s fundamental background in colloid/polymer science, industrial biotechnology and biocatalysis from the third country into the EU giving novel insights into the basic reaction mechanisms and the influence of the emulsion properties on enzyme catalysis. Thus, AquaCat will create mutually-beneficial research co-operations and enable the application of results to other valuable substrates and could soon become a feasible strategy for the European industry to design sustainable processes for high value-added products.