microbeadsImprove-Stem project (developing new bioMaterials for PROliferation and in Vitro Expansion of STEM cells) aims to develop an integrated set of tools required for mesenchymal stem cells (MSC) amplification.


The achievement of this goal involves 3 aspects:


-  The development of microcarriers with optimised surface design for stem cells culture allowing control of adhesion and detachment after multiplication,

-  The design of an adapted bioreactor with operating conditions adjusted for stem cell culture on the new microcarriers,

-  The development of standardized protocols for characterization ensuring purity, homogeneity and quality of the cells.

To achieve this goal, the consortium gathers keys competencies in materials sciences, Bioprocess engineering and cell biology. Department of Chemical Engineering, more specifically PEPS, plays a major role in the design of the bioreactor but is also the scientific and administrative lead coordinator.


The project is co-funded by FEDER up to 1 934 247€ out of a total budget of 3 223 245€ within the framework of INTERREG VA Greater Region initiative. This 3.5-year project will run from 1st January 2017 to 30 june 2020.




- Centre Interfacultaire des Biomatériaux (CEIB) of l’ULiège,

- Leibniz Institute for New Materials (INM),

- University of Kaiserslautern, 

- Luxembourg Institute of Science and Technology (LIST),

- University of Lorraine,

- Centre National de la Recherche Scientifique français (CNRS),


The project received the label "University of the Greater Region (UniGR)"




The project stems from a fact: stem cells are a major step forward in medicine but usual cell cultures methods (T-Flasks) do not provide sufficient amounts for clinical studies nor clinical application. Upscaling and automation of the process will be required in the near future to ensure reproductibility and quality of the cell acquisition process. So far, the most promising technique is based on the use of microbeads that provides a large adhesion surface. Those microbeads are suspended in a stirred bioreactor allowing stem cells to grow at their surface. This technique, already use for animals cell culture (vaccine production), presents special issues for stem cells that need to be harvested without being damaged.


Scientific Involvement of PEPs team


The team is involved in the design of the stirred bioreactor. This bioreactor must allow the microbeads to be equally spreaded in the culture medium without any shocks or mechanical effort on their surface in order to prevent the cell differentiation or cell death. At the end of the culture process, this bioreactor should also enable the cells to be separated in due time without altering them. In order to ensure this, the microcarriers are coated with a thermoreactive polymer that make cell adhesion temperature-dependent.



Wesite Interreg Programme GR

Article 15e jour


Improve-Stem Website



M.-L. Collignon, A. Delafosse, S. Calvo, C. Martin, A. Marc, D. Toye, E. Olmos. Large-Eddy Simulations of microcarrier exposure to potentially damaging eddies inside mini-bioreactors. Biochemical Engineering Journal 108, (2016) 30-43.



Contact(s) : Angélique Delafosse (research engineer) ; Florence Hautekeer (coordinator); Dominique Toye (project leader)