2014 Fiscal Year Annual Research Report
体内環境下における最先端人工関節材料のビーリングスの分光学的・力学的評価
| Project/Area Number |
14F04783
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| Research Institution | Kyoto Institute of Technology |
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Principal Investigator |
PEZZOTTI G. 京都工芸繊維大学, 工芸科学研究科, 教授 (70262962)
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| Co-Investigator(Kenkyū-buntansha) |
MARIN Elia 京都工芸繊維大学, 工芸科学研究科, 外国人特別研究員
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| Project Period (FY) |
2014-04-25 – 2017-03-31
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| Keywords | BIOCERAMICS / BIOINERTNESS / HIP JOINT / WEAR / RAMAN SPECTRA |
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| Outline of Annual Research Achievements |
As biomaterials tribology is a complex field with many variables, the first period has been spent in trying to understand and to simulate the conditions that may be found in vivo during the lifetime of the hip joint prosthetic implants, in particular for the actual ceramic oxide biomaterials such as alumina and zirconia toughened alumina, which are the actual most diffused ceramic biomaterials on the market. Finite elements simulations both for high resolution loading conditions and local temperature evaluations have been performed using dedicated software and the results have been compared with literature data and a wide array of implant retrievals. The simulations have also been used in order to predict the possible behaviour of not-oxide ceramic biomaterials, in order to understand if they may rise as a competitive technology for the same applications in the future. In order to be able to better simulate the real behaviour with a dedicated pin-on-ball tribometer, the equipment has been implemented with an adjustable, low rotation speed peristaltic pump which allows to control the amount of lubricant present on the surface of the sample at each time, recreating conditions similar to the in-vivo ones. So far, the data obtained by the simulations resulted to be in line with the literature data and the retrievals.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
The first six months of the JSPS program were spent preparing the equipment and consolidating the knowledge about the tribology of ceramic biomaterials and the biological environment in order to proceed with the experimental testing. A lot of information about chemical aggression and tribological wear in vivo was acquired on retrieval samples of alumina and zirconia toughened alumina, giving the possibility to optimize the experimental setting for the future tribological testing. This knowledge has been further enhanced by finite elements simulations. The necessary tribological equipment has been upgraded in order to be able to perform more adequate testing on the ceramic samples, also in lubricated conditions with a controllable amount of lubricant fluid, after observing that the amount of lubricant in-vivo is usually extremely limited. The achievement levels are in line with the expectations for the research program and the experiments will now be performed faster and with more reliable results thanks to the optimized procedures. The overall progress of the research program can be estimated to be between 25 and 35% respect to the initial program submitted to JSPS.
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| Strategy for Future Research Activity |
At the conclusion of the preliminary investigations and the study of the literature data available, the future research will be focused on the testing of the different ceramic biomaterials under different conditions. This will mainly involve tribological testing using the implemented pin on ball tribometer, in particular under different lubricated conditions. In order to simulate the adequate environment for lubricated conditions, various solutions will be tested, starting from demineralized water and saline physiological solution. Further solutions will then be prepared varying (lowering) the pH to simulate a more aggressive environment. The influence of lipids (squalene) will be also taken into account, as well as the presence of proteins and different salts. To further exacerbate the testing conditions, small particles of hydroxyapatite will also be added to the solution in order to act as third body and generate wear scars during the tribological testing.
The samples will be tested both in ceramic-on-ceramic and ceramic-on-polyethylene conditions to clarify which material is most suited for each specific application.
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Research Products
(1 results)
