Development of kitosan based hydrogels for biomedical applications

Chitosan is a versatile biopolymer produced from the world's most abundant kit after cellulose. The chitin is found in shellfish, insects and fungi. Chitosan can be used in biomedical applications due to its biodegradability, antimicrobial and antifungal properties. Chitosan is a non-toxic, biocompatible, biodegradable and antimicrobial polymer. Chitosan polymer is used in drug release systems, cell release systems and orthopedics, wound healing, ophthalmology, medicine and bone healing. Chitosan has a wide range of applications in drug release systems, hydrogels and wound dressings. It stimulates cell proliferation and "histoarchitectural" tissue organization. Chitosan helps in wound healing mainly due to its biocompatibility, biodegradability, antimicrobial structure as well as bacteriostatic and fungal properties. The polycationic structure of the chitosan and the interaction between the positively charged chitosan and the negatively charged cell wall lead to the leakage of intracellular components and thus the death of the harmful organism. Utilizing the biocompatibility of chitosan, it is used in various biomedical applications such as implantation, injection or topical eye applications. It was found that the chitosan film was used as a dressing, it should be robust, stress resistant, flexible, flexible and flexible, and it was easy to apply and remove to the wound without any trauma during winding changes. In this thesis, in order to obtain chitosan-based hydrogels, various modification processes were carried out in the middle molecular weight chitosan. Primarily, chitosan was modified with phthalic anhydride to protect the free amine groups and phthaloyl chitosan was obtained. In the next step, grafting process was carried out on the hydroxyl groups to combine the poly(ethylene glycol) groups with the hydroxyl properties of the chitosan and the later use of the amine groups. Following poly(ethylene glycol) inoculation, hydrazination was carried out to restore protected phthaloyl groups in their reactive forms in amino groups. In the last step, chitosanbased hydrogels were prepared by conjugation with NHS-activated 3- mercaptopropionic acid to carry out the introduction of thiol-en-reactive merkapto groups of amino groups in the side chains of PEG grafted chitosan. Properties of prepared hydrogels were characterized. Materials characterization was done by FT-IR and 1H NMR analysis. The total sulfhydryl content of thiol-modified PEG grafted chitosan was and the total thiol content of thiol-modified PEG grafted chitosan was determined using Ellman's method.