School of Natural Sciences, Parramatta Campus, University of Western Sydney, Penrith South DC, New South Wales, Australia.
Nanomedicine. 2010 Dec;6(6):707-13. doi: 10.1016/j.nano.2010.06.002. Epub 2010 Jul 3.
The tear film is a dynamic multilayered structure. The interactions and the interfacial dynamics between the layers that occur during a blink cycle must be such that they allow for maintenance of a stable tear film. Attempts to understand these dynamics have been limited by the techniques and biomarkers used. Quantum dots (qdots) offer a new potential to monitor the dynamics of the tear film layers in vivo without the drawbacks of previously used methodologies. Indium phosphide-gallium qdots were used to differentially assess the dynamics of the lipid and aqueous layers of the tear film in real time. In the aqueous, qdots dispersed to form a stable local region that was swept away into the upper and lower menisci during a blink. They did not redisperse onto the ocular surface but were progressively removed from the menisci through the puncta. Some of these qdots adhered to the mucin layer on the ocular surface in a meshlike pattern and remained there for five to six blinks before they were removed. The organic qdots dispersed quickly but patchily over the whole outer surface of the tear film. They also strongly marked both eyelid margins and slowly dispersed onto the skin and eyelashes and not through the puncta. Some were trapped in the menisci as blobs that rolled along the meniscus. These data support the view of a distinct three-layered tear film: an inner mucin layer attached to the epithelial cells, a fluid aqueous layer, and an outer viscoelastic lipid layer.
泪膜是一个动态的多层结构。在眨眼周期中，各层之间的相互作用和界面动力学必须能够维持稳定的泪膜。由于所使用的技术和生物标志物的限制，对这些动力学的理解一直受到限制。量子点 (qdots) 提供了一种新的潜力，可以在不具有先前使用的方法的缺点的情况下，在体内监测泪膜各层的动力学。磷化铟-镓 qdot 被用于实时、差异评估泪膜的脂质和水相层的动力学。在水相中，qdot 分散形成一个稳定的局部区域，在眨眼时被扫入上下穹窿。它们不会重新分散到眼表面，但会通过泪点逐渐从穹窿中去除。其中一些 qdot 以网状图案附着在眼表面的粘蛋白层上，并在被去除之前在那里停留五到六个眨眼。有机 qdot 在泪膜的整个外表面快速但不均匀地分散。它们还强烈标记上下眼睑边缘，并缓慢分散到皮肤和睫毛上，而不是通过泪点。一些 qdot 作为在泪膜中滚动的液滴被困在穹窿中。这些数据支持了具有明显三层泪膜的观点：附着在上皮细胞上的内层粘蛋白层、流体水相层和外层粘弹性脂质层。
