臺灣博碩士論文加值系統

目前可降解式固定器所面臨最大的問題在於強度的大小及降解時間的維持，為了評估可降解式固定器的降解情形，可建立一套體外的強度衰減測試流程。然而文獻上對於測試流程及方法並不一致，有鑑於國內開始研發可降解式骨科固定器，需經由強度衰減測試流程來評估材料之機械強度性質，因此本研究參考國外文獻的報導及ASTM相關標準規範，以三種不同材料之可降解式骨螺釘為對象，建立一套國內研發可降解式固定器的體外強度衰減測試模式。
體外衰減實驗方面，本研究使用恆溫水槽，提供迴旋搖晃運動，使磷酸鹽緩衝溶液(PBS)與骨螺釘表面產生相對流動，pH值維持在7.40.2，溫度控制在3720C，於設定之時間點取出骨螺釘進行強度測試。強度測試方面，本研究利用剪力及三點彎曲測試，每次測試使用五根骨螺釘，以得到衰減強度與時間的關係。PLLA骨螺釘在第6-7週時強度產生急速衰減，PLGA骨螺釘(工研院原料)在第4週強度已幾乎消失。
可降解式骨螺釘透過本研究建立之體外強度衰減之測試模式，可得到機械強度隨時間衰減的情形。此套測試模式的建立可作為國內研發可降解式固定器之體外測試評估及參考依據。

The strength magnitude and retention time of biodegradable fixation devices can be understood and improved by mean of in vitro degradation tests. However from the literature review, it is found that the testing procedure and controlled environment applied in various vitro tests are not the same. Because the development of biodegradable fixation devices is one of the strategies to promote the biotechnological industry in this country, the purpose of this research is to establish an in vitro degradation system to monitor the degradation of mechanical strength of a developed biodegradable screw.
Conditions set for In vitro degradation and mechanical tests refer to ASTM F1635 and paper reviews. The screws were manufactured by three kinds different of materials. They were put in several containers and immersed in PBS(pH=7.40.2). The temperature of buffer solution was maintained at 3720C and allowed shaking. Both of shear and three points bending tests were carries out to determine the relation between the mechanical strength and the degradation time of the screws. The resulting mechanical strength reported is an average of 5 samples. The present results indicate that the strength of PLLA screws decreased significantly among week 6 to week 7 and PLGA screws(raw material from UCL, ITRI) lost almost all of its strength at about the 4th week.
This study has established an in vitro degradation system to test the strength attenuation of a biodegradable screw. The developed system could be applied to help evaluation and developing biodegradable screws in our country.

目 錄
Page
中文摘要………………………………………………………………….I
英文摘要………………………………………………………………...II
表目錄…………………………………………………………………..IV
圖目錄………………………………………………………………..….V
第一章 前言……………………………………………………………1
1-1生物降解性材料……………………………………………………..2
1-1.1高分子alpha羥基酸--Poly(hydroxy acids)………………….3
1-1.2生物降解性(biodegradation)…………………………………….7
1-2可降解式固定器…………………………………………………....11
1-3研究動機……………………………………………………………13
1-4文獻回顧……………………………………………………………14
1-5研究目的……………………………………………………………16
第二章 研究方法與材料……………………………………………..17
2-1可降解式骨螺釘設計與製造………………………………………17
2-2 體外強度衰減測試模式…………………………………………...21
2-2.1體外衰減實驗………………………………………………....22
2-2.2強度測試…………………………………………………….....30
第三章 結果…………………………………………………………..36
3-1體外衰減實驗結果…………………………………………………36
3-2強度測試結果………………………………………………………39
3-2.1剪力測試結果………………………………………………….39
3-2.2三點彎曲測試結果…………………………………………….44
第四章 討論…………………………………………………………..49
4-1體外衰減實驗結果討論……………………………………………50
4-2強度測試結果討論…………………………………………………55
第五章 結論…………………………………………………………..62
參考文獻………………………………………………......…..63

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