Picarazzi S, Lecchi M, Pastori V, D'Arienzo M, Scotti R, Tavazzi S
University of Milano Bicocca, Materials Science Department, Via R. Cozzi 55, I-20125 Milan, Italy.
University of Milano Bicocca, Department of Biotechnology and Bioscience, Piazza Della Scienza 2, I-20126 Milan, Italy; University of Milano Bicocca, COMiB, Via R. Cozzi 55, I-20125 Milan, Italy.
Colloids Surf B Biointerfaces. 2017 Sep 1;157:26-30. doi: 10.1016/j.colsurfb.2017.05.057. Epub 2017 May 24.
This study aims to deepen the knowledge on tear film properties by the development of a protocol for analyses of Photon Correlation Spectroscopy (PCS) on human tears and by the comparison between PCS results obtained on tears of contact lens wearers and non-wearers. Tears (5μL) were collected by a glass capillary. The analyses provide the hydrodynamic diameter of tear components by analyzing intensity fluctuations in time of scattered light. PCS appears a promising technique for studying tear features and for shedding light on specific eye conditions, such as on the clinical effects of CL wear. In fact, statistical difference (p<0.001) was found between the measured mean hydrodynamic diameter of tear components of wearers and non-wearers, the resulting value significantly higher for CL wearers. The scenario does not substantially change after (25±5)min from the CL removal. The difference is attributed to changes in the interactions between tear constituents due to CL wear. In order to get deeper insights on the influence of CL wear on aggregation and structure of tear components, a preliminary Electron Spin Resonance (ESR) investigation was performed, monitoring Fe species. ESR spectra on tears of both CL wearers and non-wearers showed the presence of intense signals, probably associated to iron (III) centers in proteins such as lactoferrin, and a weaker resonance attributable to Fe species interacting with S-S bridges of lysozyme. Differences in ESR spectra between CL wearers and non-wearers were detected and tentatively ascribed to changes in coordination or in local environment of Fe centers connected to aggregation phenomena induced by CL wear, which promote their interaction with other neighboring iron species.
本研究旨在通过开发一种用于分析人眼泪的光子相关光谱法（PCS）的方案，并通过比较在佩戴隐形眼镜者和非佩戴者的眼泪上获得的PCS结果，来加深对泪膜特性的认识。用玻璃毛细管收集5微升眼泪。通过分析散射光强度随时间的波动，该分析可提供泪液成分的流体动力学直径。PCS似乎是一种很有前景的技术，可用于研究泪液特征以及揭示特定的眼部状况，例如隐形眼镜佩戴的临床效果。事实上，在佩戴者和非佩戴者泪液成分的测量平均流体动力学直径之间发现了统计学差异（p<0.001），佩戴隐形眼镜者的测量值明显更高。从摘下隐形眼镜起（25±5）分钟后，这种情况基本没有变化。这种差异归因于隐形眼镜佩戴导致泪液成分之间相互作用的变化。为了更深入了解隐形眼镜佩戴对泪液成分聚集和结构的影响，进行了一项初步的电子自旋共振（ESR）研究，监测铁物种。佩戴隐形眼镜者和非佩戴者眼泪的ESR光谱都显示存在强烈信号，可能与乳铁蛋白等蛋白质中的铁（III）中心有关，还有一个较弱的共振归因于与溶菌酶的S-S桥相互作用的铁物种。检测到佩戴隐形眼镜者和非佩戴者的ESR光谱存在差异，并初步归因于与隐形眼镜佩戴引起的聚集现象相关的铁中心配位或局部环境的变化，这促进了它们与其他相邻铁物种的相互作用。
