Demoustier-Champagne, SophieJonas, Alain M.Evrard, LiseLiseEvrard2025-05-142025-05-142025-05-142023https://hdl.handle.net/2078.2/32304Tissue engineering is a rapidly growing field dedicated to the development of functional tissue substitutes for the regeneration of damaged tissues. Porous scaffolds play a crucial role in providing structural support for cell growth, differentiation and tissue regeneration. The porosity of scaffolds is a key parameter that influences their biocompatibility, vascularization and ability to promote cell migration. On the one hand, micropores, with a size of 50 to 200 µm, allow the circulation of the cells required for the growth of new tissue. On the other hand, macropores, 300 to 500 µm in size, facilitate vascularization by providing the oxygen and nutrients essential for cell survival. This study focused on the development of a 3D-printed polymer that exhibits both porosity and biodegradability, thereby meeting the requirements of biological applications. To induce microporosity in the scaffolds, an innovative solvent-free method was developed. This method involves mixing polylactic acid (PLA) and polyethylene glycol (PEG). Based on a previous study, the composition of the mixture was set at 70% PLA and 30% PEG, but three different molar masses of PEG were investigated: PEG3K, PEO100K and PEO1M with a molar mass of 3,350 g/mol, 100,000 g/mol and 1,000,000 g/mol respectively. Firstly, filaments were made by extruding the PLA/PEG polymer blend. These filaments were then used in a 3D printer to produce 3D objects. Macroporosity was induced by the 3D printing design itself, while microporosity was successfully obtained by dissolving PEG in water, which allowed the PEG to be extracted from the structures. In principle, the lower the molecular weight of PEG, the lower its rigidity and mechanical strength. This was reflected in the prints after PEG removal as the amount of PEG remaining varied between 7 and 10%. Although the structure with PEG100K was very slightly stiffer than that with PEG1M. Molecular weight also had an effect on porosity. With PEG3K, the pores were few and medium-sized (<100 µm) and the macropores were 800 µm in size. With PEG100K, the micropores were very numerous and highly variable in size (between 15 and over 200 µm) and the macropores were 650 µm in size. Finally, PEG1M had a large number of small pores (<30 µm) and macropores 950 µm in size. The results showed that the PLA/PEO100K blend had the best combination of micropores and macropores, as well as acceptable mechanical properties. This study proposes a new approach to developing porous structures as scaffolds for tissue regeneration applications. However, further improvements are still needed, in particular the optimization of 3D printing parameters.PLAPEGPorosity3D printingtext::thesis::master thesisthesis:40564