کیمیا ممتحن، کارشناسي ارشد ناپيوسته رشته زيست فناوري – ميکروبی، دکتر الهه مسائلی

نام و نام خانوادگی:کیمیا ممتحن
عنوان پایان نامه: ساخت و مشخصه یابی هیدروژل قابل تزریق آلجینات/ ژلاتین تقویت شده با نانو بلورهای سلولز باکتریایی
رشته تحصیلی: زيست فناوري – ميکروبی
مقطع تحصیلی: کارشناسی ارشد ناپیوسته
استاد راهنما :  دکتر الهه مسائلی

چکیده:

Hydrogels that form a gel after injection into the body environment and within the biological conditions of the injection site are called in-situ injectable hydrogels.The injectable hydrogel of alginate and gelatin was tested in this experiment with the adaptation of alginate/gelatin cross networks, ionic crosslinking of alginate with calcium chlorate, and supramolecular interactions in order to create a superior tissue engineering substrate, which was mechanically strengthened by integrating bacterial cellulose nanocrystals. Therefore, in this study, Alg/Gel/BCN nanocomposite injectable hydrogels with different percentages of BCN were prepared, and their physical, chemical, mechanical, rheological properties and biological properties were evaluated. TEM results of bacterial cellulose nanocrystals showed that most particles have an average size of 28±33.72 nm and tubular morphology. The FTIR results clearly showed that strengthening the hydrogel with BCN did not change the network structure of Alg/Gel hydrogel. The XRD pattern showed an increase in the crystallinity index of the BCN sample compared to BC, which indicates the reduction of amorphous regions in BCN. In general, the results of the swelling and degradation test showed that the inclusion of BCN into Alg/Gel hydrogel has a potential role in improving the swelling and degradation rate. According to TGA results and improved thermal resistance by adding BCN, Alg/Gel/BCN nanocomposite injectable hydrogel is suitable for biomedical applications up to 200℃. The results of the compressive strength test also showed that the addition of BCN as a reinforcing agent led to the formation of denser and highly intertwined networks and thus increased the compressive strength and Young’s modulus. The results of frequency rheology showed that Alg/Gel/BCN6% hydrogels with 106 (pa) and Alg/Gel hydrogels with 105 (pa) respectively have the highest and lowest storage modulus, showing increases in the storage modulus by adding BCN and limiting polymer chains viscosity in the nanocomposite. The results of MTS assay, fluorescent microscope imaging, and Live/Dead staining showed high cell activity and normal cell morphology of fibroblasts-laden hydrogels. In general, the results of this research showed the potential of injectable BCN-reinforced Alg/Gel hydrogels as a bio-ink in 3D printing and in-situ forming gel in tissue engineering.

کلیدواژه: Bacterial cellulose nanocrystals; Injectable hydrogel; Alginate/Gelatin; Tissue engineering