Postdoctoral Researcher (M/F) in Cell and Molecular Biology – Biomaterials and Bone Organoids

Job Description

Missions

The BIOdevices, BIOmaterials & BIOengineering (3 BIO's) group within the CBMN – UMR 5248 (University of Bordeaux) is recruiting a Postdoctoral Researcher specializing in cell and molecular biology to join an interdisciplinary project at the interface of cell biology, tissue engineering, biomaterials chemistry, and advanced imaging, funded by the French National Research Agency (ANR).
The postdoctoral researcher will be responsible for developing and characterizing 3D bone tissue models from human mesenchymal stem cells (hMSCs) encapsulated within hydrogels with controlled physicochemical and mechanical properties. Particular emphasis will be placed on osteogenic differentiation, mineralized matrix formation, and interactions between bone cells and the vascular network.
Project background
The reconstruction of functional human bone tissue models is a major challenge for improving our understanding of bone formation and remodeling mechanisms and for developing new tools to study bone diseases.
In this context, the ANR MYOSMAT project aims to develop biomimetic 3D systems that closely reproduce the cellular and extracellular matrix microenvironment of bone tissue. The project relies on the use of hydrogels with controlled properties, providing cells with a three-dimensional environment suitable for their survival, organization, and differentiation.
The project follows a multidisciplinary approach combining materials chemistry, cell and molecular biology, tissue engineering, and advanced microscopy. It also incorporates the vascular component of bone tissue through the development of coculture systems combining mesenchymal stem cells and endothelial cells.
Project objective
The main objective is to develop vascularized 3D bone organoids from human cells, while controlling their biomaterial microenvironment to promote osteogenic differentiation, the formation of a mineralized extracellular matrix, and the organization of cellular structures characteristic of bone tissue.
The postdoctoral researcher will focus primarily on the biological aspects of the project and will be responsible for:
• selecting hydrogel formulations that are most favorable for cell survival and homogeneous cell distribution;
• characterizing hMSC osteogenic differentiation and extracellular matrix formation;
• analyzing organoid mineralization and three-dimensional organization;
• investigating the formation of a vascular network within the 3D constructs;
• characterizing interactions between bone cells and endothelial cells;
• investigating, where possible, ultrastructural features that mimic the organization of native bone tissue.

Activity

The postdoctoral researcher will be primarily involved in the following activities:
Cell culture and 3D models
• Culture and expansion of human mesenchymal stem cells (hMSCs).
• Cell culture within 3D hydrogels and dynamic culture systems.
• Establishment of hMSC/endothelial cell cocultures.
• Monitoring of cell viability and cell distribution within hydrogels.
• Assessment of cell viability.
• Analysis of cell distribution and morphology using confocal microscopy and 3D light-sheet microscopy.
• Analysis of cell morphology and circularity from 2D and 3D images.
Characterization of osteogenic differentiation
• Analysis of alkaline phosphatase (ALP) activity as an early marker of osteogenic differentiation.
• Quantification of calcium content in 3D constructs using the CPC Liquicolor assay.
• Analysis of mineralization by histological staining.
• Analysis of mineralization and its spatial distribution within organoids using X-ray micro-computed tomography (microCT).
• Analysis of osteogenic marker expression by RT-qPCR, Western blotting, and immunohistochemistry/immunofluorescence.
• Characterization of markers associated with different stages of osteogenic differentiation and extracellular matrix formation.
• Sample preparation for cryosectioning and histological analysis.
Cellular organization and ultrastructural characterization
• Analysis of the morphology of cells embedded within the mineralized matrix.
• Investigation of the potential acquisition of an osteocyte-like phenotype and the formation of dendritic processes.
• Characterization of the organization of the lacunar-canalicular network (LCN).
• Preparation of samples for ultrastructural analyses.
• Use of transmission electron microscopy (TEM) and, depending on project progress, FIB-SEM to investigate the 3D architecture of the constructs.
• Comparison of the ultrastructural organization of the organoids with that of native bone tissue.
Vascularization and coculture
• Establishment and optimization of hMSC/endothelial cell coculture systems.
• Analysis of vascular structure formation and lumen formation using light-sheet microscopy following tissue clearing.
• Confirmation of vascular structure formation by immunostaining, in particular CD31 staining.
• Analysis of the expression of markers involved in angiogenesis and vascular maturation.
• Use of complementary approaches, including immunostaining, ELISA, and angiogenesis arrays.
• Investigation of interactions between vascular structures and bone cells/osteocytes using advanced microscopy.
Data analysis and dissemination
• Quantitative analysis of experimental data and image processing.
• Analysis, visualization, and interpretation of experimental results.
• Presentation of results at team meetings, seminars, and scientific conferences.
• Contribution to the preparation of scientific publications and project reports.
• Participation in project meetings and scientific exchanges with the different project partners.

Your Profil

Skills

Education and scientific expertise
• PhD in cell biology, molecular biology, tissue engineering, biomaterials, bioengineering, or a related field.
• Strong experience in human cell culture, ideally with mesenchymal stem cells.
• Experience in 3D cell culture and/or culture of cells encapsulated in hydrogels or scaffolds.
• Experience with dynamic 3D culture systems and/or bioreactors would be highly appreciated.
• Strong knowledge of cell and molecular biology.
• Experience in the analysis of cell differentiation and/or molecular markers.
• Knowledge of biomaterials and hydrogels would be a strong asset.
• Experience in fluorescence microscopy and ideally confocal microscopy.
• Knowledge of image processing and analysis, particularly using ImageJ/Fiji, would be appreciated.
• Experience with RT-qPCR, Western blotting, immunofluorescence/immunohistochemistry, and/or ELISA is desirable.
• Knowledge of mineralization assessment and/or bone biology would be an advantage.
Personal skills
• Ability to work independently while contributing effectively to an interdisciplinary team.
• Strong interest in projects at the interface between biology, chemistry, and materials science.
• Initiative, scientific rigor, and strong experimental problem-solving skills.
• Ability to work collaboratively and interact with technological platforms and external partners.
• Strong analytical, synthesis, and scientific communication skills.
• Good command of English, both written and spoken.
• Experience in scientific writing and publication is an advantage.

Your Work Environment

The project will be conducted under the supervision of Marie-Christine Durrieu within the BIOdevices, BIOmaterials & BIOengineering (3 BIO's) group of the Institute of Chemistry and Biology of Membranes and Nano-objects (CBMN – UMR 5248), University of Bordeaux, as part of the recently funded ANR MYOSMAT project.
The postdoctoral researcher will join a dynamic and international interdisciplinary research environment at the interface of biomaterials chemistry, cell and molecular biology, tissue engineering, and bioimaging. The project will benefit from the infrastructure and equipment available at CBMN for cell and molecular biology experiments, as well as access to the main technological platforms available at the Bordeaux research campus.
The researcher will also interact with the scientific partners involved in the project, including members of FGHI, a company based in Montpellier.
The 3 BIO's group provides a dynamic and stimulating scientific environment built around strong interactions between cell and molecular biology, chemistry, materials physicochemistry, and bioengineering. The postdoctoral researcher will therefore benefit from a collaborative environment that will allow them to develop interdisciplinary expertise and contribute to an innovative project in the fields of bone organoids, biomaterials, and tissue engineering.

Compensation and benefits

Compensation

Between €3,041 and €4,216 gross per month, depending on experience

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

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