Purpose: Significant evidence suggests thai topographical features of the extracellular matrix (ECM) modulate cellular bchuMor. This project was undertaken to define the topographical character!sties of the ECM underlying the corneal epithelium of the Macaque using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Methods: Excised 7mm diameter comeal buttons from Macaques were placed in EDTA tor 2.5 hours and the epithelium carefully removed to expose the underlying basement membrane (Murphy el al, 1996. IOVS 37:4647). The specimens uere then dehydrated with 2-2DMP and ethanol, and critical point dried. Stereo pair images of the samples were obtained with a high resolution low voilage SEM. Parallax shift measurements were used to calculate topographical height. Additionally, tapping mode AFM was used to image multiple regions of the same samples both before and after SEM exam. AFM measures surface contours.rastcnng with a nanoscalc silicon stylus. These images can then be computer analyzed lor surface measurements including height. Results: The ECM had very complex topography consisting of small and large features including tightly crosslinkcd fibers intermingled with pores of varying siJ.cs. SEM and AFM measured feature heights were comparable with a mean of 200 nm. median of 175nm. and a standard deviation of 100 nm (range - 50nm to 400 nm). Conclusions: The complex nanoscale features play a role in mechanical epithelial cell attachment and may be involved in other cellular processes.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - 1997|
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