Composites for bone repair: phosphate glass fibre reinforced PLA with varying fibre architecture
Composites for bone repair: phosphate glass fibre reinforced PLA with varying fibre architecture
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DOI：
10.1007/s10856-011-4361-0
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发表时间：
2011-08-01
影响因子：
3.7
通讯作者：
Rudd, C. D.
中科院分区：
文献类型：
--
作者：
Ahmed, I.;Jones, I. A.;Rudd, C. D.
使用刚性金属板、螺钉和针进行骨折内固定是一种行之有效的手术技术。然而，在使用金属板进行刚性内固定后观察到了再骨折，并且已知板固定会导致板下和附近的局部骨质减少。在本研究中，可吸收的复合材料，包括与铁掺杂磷酸盐玻璃纤维增强的PLA基质进行了研究。制备纤维体积分数（V-f）约为30%和45%的非织造随机毡层压材料，沿着具有约20% V-f的单向和0A度aEuro“90 A度样品。非织造复合材料层压体实现了10 GPa模量和120 MPa强度的最大值。0- 90 A（0）样品显示出出乎意料的低强度，接近基质值（类似于50 MPa），尽管具有7 GPa的模量。UD试样的强度和模量分别为130 MPa和11.5 GPa。所观察到的所有模量值都接近从混合物规则所预期的值。浸入37 A ℃去离子水中的样品显示出快速的机械性能损失，UD和0- 90 A（0）样品更是如此。有人建议，连续纤维芯吸的降解介质进入复合材料板，加速恶化的纤维基体界面。由于复合材料内纤维的不连续排列，这种效果在非织造无规垫层压材料中不太明显，使其不太容易芯吸。随机垫复合材料显示出比UD和0A度-90A度试样更高的质量损失，这表明这是由于这些复合材料的更高的纤维体积分数，并且SEM研究显示到第3天纤维周围的空隙率。降解介质的pH值的研究表明，所有的复合材料的调查类似的配置文件。pH值的初始降低归因于磷酸根离子释放到溶液中，然后逐渐返回到中性。
Internal fixation for bone fractures with rigid metallic plates, screws and pins is a proven operative technique. However, refracture's have been observed after rigid internal fixation with metal plates and plate fixation has been known to cause localised osteopenia under and near the plate. In the present study, resorbable composites comprising a PLA matrix reinforced with iron doped phosphate glass fibres were investigated. Non-woven random mat laminates of approximately 30% and 45% fibre volume fraction (V-f) were produced, along with unidirectional and 0A degrees aEuro"90A degrees samples of approximately 20% V-f. The non-woven composite laminates achieved maximum values of 10 GPa modulus and 120 MPa strength. The 0-90A(0) samples showed unexpectedly low strengths close to matrix value (similar to 50 MPa) although with a modulus of 7 GPa. The UD specimens exhibited values of 130 MPa and 11.5 GPa for strength and modulus respectively. All the modulus values observed were close to that expected from the rule of mixtures. Samples immersed in deionised water at 37A degrees C revealed rapid mechanical property loss, more so for the UD and 0-90A(0) samples. It was suggested that continuous fibres wicked the degradation media into the composite plates which sped up the deterioration of the fibre-matrix interface. The effect was less pronounced in the non-woven random mat laminates due to the discontinuous arrangement of fibres within the composite, making it less prone to wicking. Random mat composites revealed a higher mass loss than the UD and 0A degrees-90A degrees specimens, it was suggested this was due to the higher fibre volume fractions of these composites and SEM studies revealed voidage around the fibres by day 3. Studies of pH of the degradation media showed similar profiles for all the composites investigated. An initial decrease in pH was attributed to the release of phosphate ions into solution followed by a gradual return back to neutral.