زهرا ياحي

The construction of tissue engineering scaffolds using 3D printing has become a highly researched topic in recent years. Given the unpredictable nature of bone injuries in terms of shape and size, a method capable of rapidly producing scaffolds with a structure closely resembling bone damage is essential for effective tissue repair. Among additive manufacturing methods, the Fused Deposition Modeling (FDM) technique stands out as a rapid, cost-effective, and precise approach for creating porous tissue-engineered scaffolds. Poly(lactic acid) (PLA) is a preferred polymer for FDM due to its favorable rheological properties, relatively low melting temperature, and the ease of optimizing print parameters. PLA exhibits excellent printability, high mechanical properties, and biocompatibility. In this research, the integration of Willemite nanoparticles onto the surface of 3D-printed PLA bone tissue scaffolds was explored to enhance biocompatibility and improve performance in in vitro and ex vivo tests. Willemite nanoparticles were synthesized using a sol-gel method, and their crystalline phase was characterized using X-ray Diffraction (XRD), with particle size determined through Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM). The scaffolds were printed using FDM, subjected to alkaline treatment, and immersed in a Willemite nanoparticle suspension to achieve surface coating. The effects of alkaline treatment on scaffold arm diameter reduction, porosity, ultimate compressive strength, and Young's modulus were investigated using Central Composite Design-Response Surface Methodology. Results indicated that employing Tetraethyl orthosilicate (TEOS) as the Si source and calcining the samples at 950°C for 3 hours could yield alpha-phase nanostructured Willemite powder. Additionally, optimum alkaline treatment conditions were determined as 6 hours and pH=11. Characterization of coated scaffolds, alkaline-treated scaffolds, and untreated PLA scaffolds was carried out using Energy-Dispersive X-ray Spectroscopy (EDS), mapping, Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). Functional eva‎luation through in vitro testing and cellular assays demonstrated significantly enhanced cell viability and mineralization of human dental pulp stem cells on Willemite-coated scaffolds compared to untreated scaffolds. This research contributes to the advancement of 3D-printed tissue engineering scaffolds by introducing a surface modification technique using Willemite nanoparticles, showcasing promising results for improved bone tissue regeneration.

پرينت سه بعدي , مهندسي بافت استخوان , نانوذرات ويلميت , داربست , اصلاح سطح

3D printing , bone tissue engineering , willemite nano particles , scaffold , surface modification

zahra yahay

dr. hamidreza rezaie; dr. seyed mohammad mirkazemi