Soukaïna El Hajj thesis defence

A clinically-relevant strategy to repair critical-sized bone defects by pre-loading a composite pullulan/dextran (PUDNA/HAp) hydrogel with pre-angiogenic and pre-osteogenic constructs.

 

 

Large bone defects remain a clinical challenge, driving the need for effective biological alternatives. This thesis developed a translational bone tissue engineering strategy to restore structure and function. A porous, biocompatible pullulan/dextran hydrogel enriched with hydroxyapatite was used to induce the 3D aggregation of hBMSCs and HUVECs into spheroids, enhancing cell interactions. Additionally, co-culture promoted early vascularization, key for engineering complex, functional tissues. Culture was maintained in a perfusion bioreactor, ensuring long-term viability and nutrient diffusion. CFD simulations confirmed effective mass transport within the system. This integrated strategy yielded highly promising results: in vitro, it enhanced both angiogenic and osteogenic outcomes; in vivo, in a critical-sized femoral defect model in nude rats, it significantly increased in situ vascularization and improved the trabecular architecture of the newly formed bone.

Members of the Jury :

• Cécile LEGALLAIS, DDR CNRS, UTC Compiègne, Présidente et Rapporteur
• Emmanuel PAUTHE, Professeur, Université de Cergy Pontoise,Rapporteur 
• Teresa SIMON-YARZA CR, INSERM, Université Paris Cité, Examinatrice
• Christophe EGLES, Professeur, Université de Rouen Normandie, Examinateur 
• Florence Agnely Professeure, Université Paris-Saclay, Examinatrice