Surface modification of chitosan films/meshes for biomaterial applications için kapak resmi
Surface modification of chitosan films/meshes for biomaterial applications
Başlık:
Surface modification of chitosan films/meshes for biomaterial applications
Yazar:
Işıklı, Berçin, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
xii, 100 leaves: color illustraltions, charts;+ 1 computer laser optical disc.
Özet:
Modification of surface of biomaterials is a great interest for many years due to first contact of surface of materials with the biological fluids. This thesis aims to investigate surface modification effect on the chemical, surface wettability, protein adsorption as well biodegradability properties of dense chitosan (Ch) and asymmetric chitosan films (ACh). The surfaces of chitosan dense and asymmetric films were modified by ion implantation technique using carbon and carbon-nitrogen hybrid ions at a fluence of 1x1015 ions/cm2 and ion energy of 20kV. Chemical compositions of the film surfaces were analyzed by Fourier transform infrared spectroscopy (FTIR-ATR). Surface hydrophobicity measurements were conducted by static contact angle measurements. Protein adsorption on unmodified and modified surfaces on films was investigated as a function of time at various pH conditions. After ion implantation on chitosan films, both C and C-Nitrogen ion implantation, the surfaces become rougher and hydrophobic having moderate wettability (􀄬 values in the range of 72-85°) and in good agreement with FTIR-ATR data findings. It was found pH dependence of the amount of protein adsorbed on the dense chitosan films as a function of time for both un-implanted and implanted films. BSA and fibrinogen were more adsorbed on the chitosan films at pH 5. The amount of BSA and fibrinogen protein adsorption was 0.97 and 1.33 gprotein/gfilm, respectively for 60 min incubation period. Protein adsorption enhanced for C and C+N2 ion implanted samples for BSA and fibrinogen, respectively due to the hydrophobic protein surface interaction effect. In vitro degradation results showed that ACh films degrade much faster (mass loss 57 %) than Ch films (40 %) due to the porous structure at the end of 3 weeks. However, the ion implanted Ch samples degraded much slower having mass loss of 30% and 17.7% for C+N2 and C implanted samples, respectively at the end of 3 weeks compared to un-implanted Ch films as 40 %. The results are in good agreement with water sorption and surface hydrophobicity of the implanted films. This study demonstrated that surface modification, as well as structure, changes the protein sorption, wettability and biodegradation properties of the chitosan films.
Yazar Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology: Biotechnology.

İzmir Institute of Technology: Biotechnology (Master).
Elektronik Erişim:
Access to Electronic Versiyon.
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