Reactions inside polyelectrolyte complexes

Reactions inside polyelectrolyte complexes

Giulia Allegri (PhD Candidate), Prof. Dr. Ir. Jurriaan Huskens (promotor), Dr. Ir. Saskia Lindhoud (co-promotor)

Duration: 2021-2025



Biological cells carry out complex biochemical reactions and processes within specific compartments known as organelles. These compartments are formed by membrane encapsulation, but it has also been discovered that liquid-liquid phase separation can create similar compartments, known as membrane-less organelles (MLOs). MLOs are dynamic droplet-like structures that selectively partition and release specific target molecules via electrostatic interactions between negatively charged polynucleic acids and positively charged proteins. To enhance our understanding of this selective molecule partitioning and develop aqueous-based extraction media, we are using polyelectrolyte complexes (PECs) as model systems.


Polyelectrolyte complex, enzymatic reactions, extraction media.

Technological challenges

PECs are formed when aqueous solutions of oppositely charged polyelectrolytes are mixed and phase-separated into a dense polymeric phase and a dilute aqueous phase. Previous studies have shown that PECs can be used to extract and back-extract proteins and small molecules, making them promising candidates for extraction media.

To understand why and under what conditions proteins and other molecules are taken up by PECs, we need to know where all the components are. Therefore, we are developing a method to fully characterize PEC systems, in which we can determine the amount of free polyelectrolytes and ions in the dilute phase and the composition, water content and amount of ions in the polymer-rich phase.


Research goals

This research will focus on: (i) characterizing 2-3 component PEC systems at different charge ratios, (ii) performing an enzymatic reaction within PECs.



Schematic of PECs formation.


I earned my Bachelor’s degree in Chemistry from the University of Parma (Italy) in March 2018. In December 2020, I completed my Master’s degree in Industrial Chemistry at the same university, with a thesis entitled “Study of the recruitment of receptors in a weak multivalent binding system”.

Since April 2021, I have been a PhD candidate at the University of Twente, where I am working under the supervision of Saskia Lindhoud. My research project focuses on studying reactions within polyelectrolyte complexes.