UCD School of Biosystems and Food Engineering, University College Dublin, Ireland.
Department of Mechanical Engineering, School of Engineering, University of Birmingham, United Kingdom.
Acta Biomater. 2018 Jun;73:81-89. doi: 10.1016/j.actbio.2018.03.045. Epub 2018 Apr 5.
Hyperspectral chemical imaging (HCI) is an emerging technique which combines spectroscopy with imaging. Unlike traditional point spectroscopy, which is used in the majority of polymer biomaterial degradation studies, HCI enables the acquisition of spatially localised spectra across the surface of a material in an objective manner. Here, we demonstrate that attenuated total reflectance Fourier transform infra-red (ATR-FTIR) HCI reveals spatial variation in the degradation of implantable polycarbonate urethane (PCU) biomaterials. It is also shown that HCI can detect possible defects in biomaterial formulation or specimen production; these spatially resolved images reveal regional or scattered spatial heterogeneity. Further, we demonstrate a map sampling method, which can be used in time-sensitive scenarios, allowing for the investigation of degradation across a larger component or component area. Unlike imaging, mapping does not produce a contiguous image, yet grants an insight into the spatial heterogeneity of the biomaterial across a larger area. These novel applications of HCI demonstrate its ability to assist in the detection of defective manufacturing components and lead to a deeper understanding of how a biomaterial's chemical structure changes due to implantation.
The human body is an aggressive environment for implantable devices and their biomaterial components. Polycarbonate urethane (PCU) biomaterials in particular were investigated in this study. Traditionally one or a few points on the PCU surface are analysed using ATR-FTIR spectroscopy. However the selection of acquisition points is susceptible to operator bias and critical information can be lost. This study utilises hyperspectral chemical imaging (HCI) to demonstrate that the degradation of a biomaterial varies spatially. Further, HCI revealed spatial variations of biomaterials that were not subjected to oxidative degradation leading to the possibility of HCI being used in the assessment of biomaterial formulation and/or component production.
高光谱化学成像（HCI）是一种新兴技术，它将光谱学与成像相结合。与大多数聚合物生物材料降解研究中使用的传统点光谱法不同，HCI 能够以客观的方式在材料表面获取空间局部化的光谱。在这里，我们证明衰减全反射傅里叶变换红外（ATR-FTIR）HCI 揭示了可植入聚碳酸酯氨酯（PCU）生物材料降解的空间变化。还表明，HCI 可以检测生物材料配方或样品生产中的可能缺陷；这些空间分辨图像揭示了局部或分散的空间异质性。此外，我们展示了一种映射采样方法，该方法可用于时间敏感的情况，允许在更大的组件或组件区域上进行降解研究。与成像不同，映射不会生成连续的图像，但可以深入了解生物材料在更大区域内的空间异质性。HCI 的这些新应用证明了它在检测有缺陷的制造组件方面的能力，并深入了解了生物材料的化学结构由于植入而发生变化的方式。
植入式设备及其生物材料组件在人体环境中是具有攻击性的。在这项研究中特别研究了聚碳酸酯氨酯（PCU）生物材料。传统上，使用 ATR-FTIR 光谱法仅在 PCU 表面的一个或几个点上进行分析。然而，采集点的选择容易受到操作人员的偏见，并且可能会丢失关键信息。本研究利用高光谱化学成像（HCI）来证明生物材料的降解在空间上是不同的。此外，HCI 揭示了未经历氧化降解的生物材料的空间变化，这使得 HCI 有可能用于生物材料配方和/或组件生产的评估。
