關節液成份分子於不同測試條件下對人工關節材料之摩擦影響

The Effects of Synovial Fluid Compositions on the Friction of Artificial Joint Materials under the different test Condition

蔡政諺(Cheng-Yen Tsai)

指導教授 ： 方旭偉

國立臺北科技大學/工程學院/化學工程研究所/碩士(2008年)

摘要

現今人工關節植入物的材料主要是由鈷鉻鉬合金金與超高分子量聚乙烯組合。然而，超高分子量聚乙烯所產生的磨耗顆粒會引起人體一連串的免疫反應，進而引發骨溶解現象，最後造成人工關節鬆脫。當人工關節作動時，兩關節對磨表面的摩擦機制會因接觸壓力與存在於關節界面的關節液分子不同而有所不一樣。因此，對於人工關節材料在不同荷重與不同關節液分子的潤滑機制需進一步的研究探討，以了解關節液分子在摩擦系統中所扮演的角色。
本研究利用摩擦測試系統，針對關節液分子白蛋白(albumin)、γ-球蛋白(γ-golbulin)、磷脂質(lipid)、玻尿酸(hyaluronic acid)及多成份關節液分子進行摩擦測試。由實驗結果發現，單成份關節液分子在5MP的接觸壓力下摩擦係數比0.25MPa小；其中以玻尿酸各別在兩者接觸壓力下所獲得摩擦係數最小。然而，關節液為多成份分子的液體，分子之間彼此交互作用會產生不同的潤滑機制。因此，我們進一步的來了解雙成份及多成份關節液分子對人工關節潤滑機制的影響。實驗結果發現，雙成份潤滑液在接觸壓力5MPa摩擦系統中，磷脂質混合白蛋白與γ-球蛋白的摩擦係數較混合玻尿酸高。另一方面，將白蛋白、γ-球蛋白、磷脂質及玻尿酸配製成生理濃度混合時，發現在沒有添加白蛋白和γ-球蛋白的摩擦係數最低；而沒有添加玻尿酸所獲得的摩擦係數最高。可能是因玻尿酸的存在可以促進兩對磨表面的潤滑，降低摩擦力。
文獻得知蛋白質的存在會使人工關節摩擦係數增加。從實驗結果發現，變質白蛋白的摩擦係數比沒變質的白蛋白高，且兩者摩擦係數隨接觸壓力的增加而降低。摩擦過後的白蛋白經SDS-PAGE實驗發現，其分子量有明顯改變。我們推測白蛋白經摩擦過後，其分子之間的共價鍵被破壞，進而影響其摩擦係數。因此，我們針對關節液含量最豐富的白蛋白在人工關節摩擦測試系統中必須做更深入的了解。

關鍵字

鈷鉻鉬合金金 ； 超高分子量聚乙烯 ； 摩擦係數

並列摘要

Joint prosthesis is mainly composed of cobalt-chromium-molybdenum (Co-Cr-Mo) and ultra-high molecular weight polyethylene (UHMWPE). However, the wear particles of UHMWPE are generated in the peri-prosthetic tissue may induce the innate immune response and osteolysis which lead to loosing of the total joint replacement. The motion of joints involves several lubrication models under CoCrMo-on-UHMWPE articulating surface between different nominal contact pressure and synovial fluid molecules. Therefore, in order to understand the role of the lubricating mechanism of synovial fluid, we should further study the influence of the different normal load and synovial fluid molecules on the tribological behaviors of artificial joints.
In this study, we applied tribological test lubricant to albumin, γ-globulin, lipid, hyaluronic acid and multi-components in the synovial fluid. The result of the friction coefficient was showed lower under the contact pressure of 5MPa than 0.25MPa for one-component lubrication. The friction coefficient is lowest in the hyaluronic acid under the two contact pressure individually. However, multi-component in the synovial fluid interacts with each other, also influence the lubricating mechanism. Thereby, we have to investigate double components and multi-components synovial fluid lubrication mechanism of artificial joint. It was demonstrated that the friction coefficient were the lowest when lipid mixed hyaluronic acid than mixed albumin andγ-globulin under contact pressure of 5MPa. On the other hand, mixing the albumin, γ-globulin, lipid and hyaluronic acid are composed of physical concentration, it shows that the friction coefficient were lower without protein, but without hyaluronic acid were not. It could reduce friction force when the hyaluronic acid existed.
The friction coefficient increase for the artificial joints when the lubricant contains proteins. It shows that the denatured albumin friction coefficient is higher than the nature albumin, and increase the contact pressure leads to the friction coefficient decrease. Changes in the molecular weight of albumin were measured by SDS-PAGE after friction experiment with a tribometer. We consequence of the covalent bond of albumin is destroyed by frictional shearing actions and then effects of friction coefficient to artificial joints. Thereby, the final goal of the study is to understand the abundant albumin in the synovial fluid under the frictional test system of the artificial joints.

並列關鍵字

CoCrMo ； UHMWPE ； friction coefficient

參考文獻

李偉銘，摩擦過程引發生物潤滑液變化對軟骨及人工關節材料摩擦性質之影響， 碩士論文，國立台北科技大學或學工程所，台北，2006。

施孟琳，關節潤滑液分子對人工關節材料摩擦行為之影響，碩士論文，國立台北科技大學或學工程所，台北，2007。

Affatato, S., Fernandes, B., Tucci, A., Esposito, L., Toni, A. "Isolation and morphological characterisatio of UHMWPE wear debris generated in vitro," Biomaterials, vol.22, 2001, pp.2325-2331.

Brockett, C., Williams, S., Jin, Z., Isaac, G., Fisher, J. "Friction of total hip replacements with different bearings and loading conditions," Journal of Biomedical Materials Research-Part B Applied Biomaterials, vol.81(2), 2007, pp.508–515.

Bergmanna, G., Graichena, F., Rohlmanna, A., Verdonschotb, N., van Lenthe, G. H. "Frictional heating of total hip implants. Part 2: finite element study," Journal of Biomechanics, vol.34, 2001, pp.429–435.