| Summary: | 碩士 === 國立臺灣大學 === 化學工程學研究所 === 87 === Collagen is a major component of human extracellular matrix. As a biomaterial, it has been broadly used in clinical therapy. The sterilization method for collagen either by filtration or high temperature is not effective due to its high viscosity and the necessity of operation at low temperature. Additionally, collagen matrices need to be modified for specific applications. This study focused on the film form of collagen matrices. Collagen films were sterilized and modified by -irradiation. The effect of sterilization and the material and mass transfer characteristics of collagen films were investigated. These results may contribute to the future application of collagen films.
Collagen purified from porcine tendon was utilized to form a film-like matrix by vacuum drying. The sterilization of collagen films was carried out by -irradiation with dose of 0.5, 1.0, 2.0, or 4.0 Mrad. The results indicated that collagen films were sterilized effectively when the dose of -irradiation was over 0.5 Mrad.
The surface structure, thermal stability, mechanic strength, and degradability of collagen films were characterized by SEM, DSC, tensile strength instrument, and collagenase digestion, respectively. SEM analysis indicated that with increasing dose of -irradiation the surface of collagen film became smoother and the films thickness after swelling became smaller. Complex layer-like structure was observed on the surface of collagen film with no fibrous structure. Moreover, there was an apparent decrease in the transition temperature and mechanical strength of collagen film after being treated with -irradiation.
From the collagen digestion experiment, it was found that the degradability of collagen films treated with -irradiation of 2.0 or 4.0 Mrad was lower than untreated ones. However, there was no obvious difference between collagen films treated with 0.5 or 1.0 Mrad -irradiation and untreated ones. The data suggest that -irradiation has both degrading and crosslinking effects on the collagen films.
In the mass transfer analysis, the permeability and partition coefficient of theophylline, benzocaine, and BSA in collagen films were determined, and then their diffusivities were computed. The results indicated that after being treated with -irradiation, the flux of small molecules like theophylline and benzocaine in collagen film was increased, but the permeability, partition coefficient, and diffusivity were not significantly altered. Theophylline, a hydrophilic molecule, had better mass transfer characteristics than benzocaine which is hydrophobic. BSA, a protein macromolecule, had worse mass transfer characteristics in -irradiated collagen films when compared with untreated films.
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