| Summary: | 碩士 === 國立成功大學 === 生物醫學工程學系 === 102 === Repairing damaged articular cartilage is challenging since its limited self-repair ability of hyaline cartilage. Nowadays, several treatments are available for repairing damaged cartilage. However, most of them still remain controversial for numerous problems. For instance, the repaired tissues by microfracture turned into fibrous cartilage. And autologous osteochondral plug repairmen exists some issue about integration with native tissue. Also, chondrocytes in vitro monolayer culture will lead to dedifferentiation then lose its original phenotype. Tissue engineering cartilage provides alternative approach to provide hope for cartilage repairing. The structure and property of scaffold can determine the outcome of tissue regeneration. This study proposes to use small and large pore size of PLGA scaffold to maintain chondrocytes and osteoblasts respectively; and surface treatment on scaffold with ethylenediamine or tyramine to assist scaffold and tissue integration.
In part I study, diameter 3 mm, height 3 mm PLGA scaffold was fabricated by salt leaching method. The biphasic PLGA scaffold with 89% porosity and 300 μm and 100 μm pore size for bottom and top layer respectively, was fabricated for chondrocytes culture. The results from histology and SEM show the chondrocytes remain its rounded phenotype appearance in 5-day culture in small pore size scaffold. From cell membrane label fluorescent and SEM results, both examine methods prove that after 5 days culture in small pore size upper layer scaffold, chondrocytes can maintain its rounded phenotype.
In part II study, biphasic scaffolds treated with ethylenediamine or tyramine and no treatment control group were pressed into 8 mm porcine osteochondral plug with defect 3 mm diameter and 3 mm depth for 4 weeks to test the integration of these scaffolds. The push out test was practiced to confirm the adhesive stress between scaffold and porcine cartilage. And this result shows tyramine treated group has the highest adhesive stress. On the other hand, from immunohistochemical stain, tyramine treated group appears better hyaline cartilage regeneration.
This study shows small pore size scaffold can successfully maintain chondrocytes phenotype, and surface tyramine treated PLGA scaffold can assist its integration with surrounding tissue.
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