Research on properties of photo-polymerized biodegradation materials for tissue engineering scaffolds fabrication by rapid prototyping technology

• Main Authors: Yi-chueh Hsu, 許貽珏
• Other Authors: Yih-lin Cheng
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/67dadt

碩士 === 國立臺灣科技大學 === 機械工程系 === 95 === In the previous Dynamic Mask Rapid Prototyping System developed in our laboratory, PLGA was mixed with PEG-HEMA to create scaffolds. During the fabrication, the finished scaffold layers continue to be soaked in the organic solvent, resulting in re-dissolution of the non-photo-crosslinked material (or called semi-interpenetrating networks, semi-IPNs). In order to solve this problem, biodegradable materials were modified to improve crosslink in this research. Moreover, degradation tests and in vitro cell culture were performed to understand properties and differences of the modified materials. In the material modification, the OH bond of PLGA end was replaced by the C=C bond of the acrylate group, which can be photo-initiated to crosslink. Due to the large differences in molecular weight between PLGA and acrylate group, it may cause problems in verifying the acrylate replacement. Therefore, PCL-PEG-PCL with less molecular weight but similar structure to PLGA was also synthesized and replaced by acrylate group to assist the verification of the material modification. Both modified materials were successfully examined by the Nuclear Magnetic Resonance and the Infrared Rays Spectroscopy. The tensile strength of cured materials were obviously increased to demonstrate the crosslink networks exist instead of semi-IPNs. In addition, in order to prove the re-dissolution problem has been solved, the cured thin films of the modified materials were soaked in the chloroform solution and measured the weight loss. The results showed that the improvement of re-dissolution problem was closely related to the acrylate group grafting ratio. Degeneration test included water absorption ratio, pH value test, and weight loss ratio. Because the replacement of acrylate groups partially destroyed the original crystalline structure, the modified materials showed slightly faster degradation. L929 fibroblast cells and MG63 human osteoblast-like cells were cultured on porous scaffolds in vitro for three days. The cell growth morphology was observed by optical microscope and SEM, and evaluated by MTT assay kits. This research successfully modified biodegradable PLGA and PCL-PEG-PCL materials and improved the re-dissolution problem. The modified materials degraded slightly faster, but the non-biodegradable acrylate group did not affect cell growth.