| Περίληψη: | The aim of this thesis is the fabrication of accurate 3-dimentional polylactic acid scaffolds (PLA) reinforced with graphene nanoplatelets (GNPs) by fused deposition modeling 3D printing (FDM 3D printing) with well-defined different pore sizes, as well as their surface modification by hydroxyapatite deposition to study the cellular response in bone tissue engineering applications. First, the scaffolds underwent compression tests to study the mechanical behavior of the reinforced PLA-GNPs scaffolds in comparison with the non-reinforced PLA scaffolds. Compact samples were also subjected to compression tests to study the mechanical behavior of the material without taking into account the porosity. The experiments did not show change in the modulus of elasticity of both scaffolds and the solid specimens between the reinforced PLA-GNPs and those of the unreinforced PLA. This is probably due to the small percentage of reinforcement (1%) as well as the fact that the two filaments (PLA and PLA-GNPs filaments), were obtained from different manufacturers. Ιt should be noted that the GNPs dispersion and thickness are not published by the manufacturer. Next, the scaffolds were superficially modified by deposition of hydroxyapatite, the main mineral component of higher mammals. The deposition was done from calcium phosphate solutions supersaturated with respect to hydroxyapatite at constant solution supersaturation. Finally, the cellular response of the enhanced scaffolds was studied with an MTT cell proliferation test. As a conclusion, both the modified scaffold models do not present cytotoxicity and particularly the modified PLA-GNPs scaffolds with 500μm pore size seem to induce cell proliferation.
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