ساخت و بررسي تركيب نانوكامپوزيتي پلي¬كاپرولاكتون / كيتوسان / نقاط كوانتومي گرافن براي استفاده در مهندسي بافت عصب

In this study, the fabrication and eva‎luation of physical, mechanical, chemical, and biological properties of PCL/CH/GQDs nanocomposite scaffolds for use in nerve tissue were investigated. First, 5 samples of scaffolds with different percentages of GQDs were made by electrospinning method. Then, the samples were subjected to X-ray diffraction spectroscopy and Fourier transforminfrared spectroscopy (FTIR) for physicochemical characterization, which showed the uniform distribution patterns and significant influence of graphene quantum dots on the structure of composite scaffold fibers. Also, the images obtained from the scanning electron microscope and the fluorescent microscope showed the presence and brightness of graphene quantum dots along the fibers and a noticeable effect on reducing the diameter of the electrospun fibers. Investigating the electrical conductivity of the samples demonstrated that adding 0.5% to 1% of graphene quantum dots to the composite will significantly increase the electrical conductivity. By conducting the contact angle test and also the cytotoxicity test with the PC12 cell line, the hydrophilicity of the scaffolds and the cell viability were eva‎luated, which shows that the cell viability increases after adding 0.5% to 2% by weight of graphene quantum dots to the sample. Also, increasing the graphene quantum dots up to 4% by weight to the composite caused toxicity. The degradation test during the 2-month immersion of the samples in PBS solution also showed an increase in the degradation rate proportional to the increase in the amount of graphene quantum dots. The mechanical properties were investigated by tensile test, and an increase of 0.5% to 1% of graphene quantum dots in the samples increased the strength and modulus of elasticity, and an increase of more than this amount caused brittleness and reduced strength of the samples. According to the studies conducted in this research, it seems that the scaffolds containing 0.5% and 1% by weight of graphene quantum dots, which are introduced as S2 and S3, are suitable candidates for use in nerve tissue engineering.

5

محمد رفيعي نيا