Description du sujet de thèse

Extrusion bioprinting is an emerging technique to fabricate synthetic living tissues. Materials for extrusion bioprinting, i.e. bio-inks, typically consist of a cell population suspended in a biopolymer-based hydrogel. Nowadays, intense research efforts focus on the design of bio-inks which can change shape after the printing process in response to external stimuli. Such “shape-morphing” printed construct would be extremely interesting as they could accurately mimic the intricate and dynamic structure of living tissues. However, this implies the design of inks that can host cells, while being extrudable and capable of undergoing a programmable actuation (= shape change).
To address this issue, this PhD project proposes to conceive and study a new class of inks by combining a crosslinkable polysaccharide matrix with rigid microfibers and a cell population.
First, the experimental work will focus on tailoring the chemistry and physicochemical properties of these inks to allow for their extrusion in 3D and their immobilization by cross-linking. Then, the inks will be printed to create hydrogel constructs displaying an anisotropic microstructure thanks to the presence of the embedded microfibers. Accordingly, these structures will swell anisotropically in aqueous media and undergo a shape transformation. This deformation, controlled by the microfibers, will be thoroughly investigated and will be further used to fabricate shape-morphing biomaterials (i.e. cell-laden printed architectures).
This work is envisioned to lead to biomaterials with sophisticated architectures and unparalleled shape morphing abilities, thereby being a breakthrough in the field of tissues engineering.

Contexte de travail

The PhD will take place in the Research Center on Vegetal Macromolecules (CERMAV) in Grenoble, France, in the “Structure and Modification of Polysaccharides” team (SMP), under the supervision of Dr. Raphaël Michel. The CERMAV (Unité Propre de Recherche for which the CNRS is the supervisor, a fundamental research centre) is a leading research laboratory in the field of glycoscience, with strong and multidisciplinary expertise that spans from chemistry, physical-chemistry, biology to material sciences and aims at addressing major societal challenges in the fields of human health, emerging energies and materials for new technologies. Ideally located on the campus of the Grenoble Alpes University (UGA), the CERMAV actively contributes to the exceptional scientific and technological environment present in the Grenoble area. The SMP team, led by Prof. Rachel Auzély-Velty is expert in the chemical modification of polysaccharides, and their use in the design of functional hydrogels for biomedical applications. Biological aspects of the project will be performed in cooperation with the team of biologists led by Dr. Lucie Sancey at the Institute for Advanced Biosciences (IAB) also located in Grenoble.

The position is intended for a highly motivated student with an extensive theoretical knowledge and a solid practical experience in the field of polymer chemistry and physical chemistry (M.Sc. in related fields). The candidate should have a good command of English and be willing to engage in multidisciplinary activities (chemical synthesis, physico-chemical characterization, biological studies). He/She should be able to work collaboratively in a highly interdisciplinary and international environment and to properly record, organize and analyze data as well as to report on his/her findings.