Determining the mechanical properties of human corneal basement membranes with atomic force microscopy.
Biophysical cues such as substrate modulus have been shown to influence a variety of cell behaviors. We have determined the elastic modulus of the anterior basement membrane and Descemet's membrane of the human cornea with atomic force microscopy (AFM). A spherical probe was used with a radius approximating that of a typical cell focal adhesion. Values obtained for the elastic modulus of the anterior basement membrane range from 2 to 15 kPa, with a mean of 7.5+/-4.2 kPa. The elastic modulus of Descemet's membrane was found to be slightly higher than those observed for the anterior basement membrane, with a mean of 50+/-17.8 kPa and a range of 20-80 kPa. The topography of Descemet's membrane has been shown to be similar to that of the anterior basement, but with smaller pore sizes resulting in a more tightly packed structure. This structural difference may account for the observed modulus differences. The determination of these values will allow for the design of a better model of the cellular environment as well as aid in the design and fabrication of artificial corneas.
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Julie A
JA
Department of Surgical Sciences, School of Veterinary Medicine, 2015 Linden Drive, University of Wisconsin, Madison, WI 53706, USA.
Liliensiek
Sara J
SJ
Nealey
Paul F
PF
Murphy
Christopher J
CJ