PhD student (M/F)

Job Description

Thesis Subject

The OMMM project (Optimization of 3D Printing of Fibrillar Matrices for Biology Using Computational Mechanical Models) aims to develop innovative biomaterials for cell culture. These biomaterials, known as fibrillar scaffolds, replicate the architectural and mechanical properties of natural extracellular matrices. Unlike traditional hydrogels, these scaffolds allow for the decoupling of porosity and stiffness, thereby providing a unique tool for studying the specific influence of each parameter on cellular behavior. The project is structured around four main areas of focus. The first area concerns the fabrication and mechanical characterization of the scaffolds. Using two-photon 3D printing, networks of sub-micrometer fibers will be created with precise control over their diameter and organization. Movable fibers will be introduced to allow for remodeling of the biomaterial, while mechanical testing coupled with optical imaging and fluorescence microscopy will be used to characterize their properties. The second research area focuses on finite element modeling of the scaffolds. In collaboration with the Clément Ader Institute, a digital twin will be developed to predict the mechanical properties of the biomaterials. This model will be calibrated using an “FEMU” approach that compares experimental data with simulations. Mechanical parameters, such as fiber stiffness and plasticity, will be identified using techniques such as atomic force microscopy. The third area of focus will be on the automated design of scaffolds. A topological optimization algorithm will be used to design fiber architectures that meet target mechanical and architectural properties. Constraints associated with 3D printing, such as fiber shrinkage, will be taken into account to ensure the feasibility of the proposed designs. Finally, the fourth research area will study the interactions between cells and scaffolds. In collaboration with the IRSD, the tensile forces exerted by cells (such as fibroblasts) on the fibers will be measured. The digital twin will enable the quantification of these forces based on observed deformations, providing valuable insights into cellular behavior as a function of phenotype or applied treatments. The OMMM project combines microfabrication, mechanical modeling, and cell biology to create custom-made biomaterials. This approach addresses major challenges in biotechnology, including the reduction of animal testing and the development of tissue models for applications in regenerative medicine.

Your Work Environment

The OMMM project is part of a scientific context in which biomaterials for 3D cell culture play a key role in biotechnology and regenerative medicine. Natural extracellular matrices (ECMs), with their architectural (porosity, fiber organization) and mechanical (elasticity, viscosity) properties, strongly influence cellular behavior. However, current biomaterials—primarily hydrogels—do not allow these parameters to be decoupled, thereby limiting their usefulness for studying the specific impact of each property on cells. The OMMM project proposes an innovative approach using two-photon 3D printing to fabricate fibrillar scaffolds that faithfully reproduce the microarchitecture of natural ECMs. These scaffolds allow for independent control of porosity and mechanical properties, thanks to sub-micrometer fibers and adjustable bonds. The introduction of mobile fibers aims to mimic the dynamic remodeling of ECMs, providing a unique tool for studying cell-matrix interactions. The project is based on a collaborative ecosystem involving LAAS-CNRS, the Clément Ader Institute, and IRSD, combining microfabrication, mechanical modeling (using digital twins and finite element models), and cell biology. This interdisciplinary approach makes it possible to predict and optimize the properties of scaffolds, while measuring the tensile forces exerted by cells, for applications in cell therapies and organs-on-a-chip. In line with regional (Occitanie) and national (PEPR Med-OoC) initiatives, the project aims to reduce animal testing and develop more accurate tissue models. It thereby strengthens Toulouse's position as a center of excellence in biomaterials and bioengineering.

Constraints and risks

Work with CMR chemicals

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions