engleski

Nanomechanical characterization of the stiffness of eye lens cells

The eye’s lens is a biological marvel, a complex structure comprising about 1, 000 layers of perfectly clear cells. It has undergone several adaptations to fulfill its function to focus light originating from distant objects onto the retina where photoreception takes place. In order to focus to different distances the lens must accommodate its shape implicating that the lens is, in contrast to a solid glass lens, flexible. Atomic force microscopy (AFM) is a powerful tool to study the mechanical properties of biological objects with high spatial precision. Here we have used AFM featuring a spherical tip at the end of a soft cantilever to indent single fibre cells isolated from lens core and cortex. Quantitative characterization of each type of lens cells was performed by the determination of the Young’s modulus of elasticity. The elastic modulus of nuclear lens cells (4.69 kPa) was 20-fold higher than that of cortical lens cells (0.251 kPa) showing that single cells from the lens core and cortex can be unambiguously distinguished using the elastic modulus as criterion. Such measurements, carried out on the single cell level, will allow studying the effect of drugs and of aging on the mechanical properties of lens cells, and thus provide novel quantitative insights to accommodation and lens pathologies.

lens cells stiffness; atomic force microscopy

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