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Download fileVariably Elastic Hydrogel Patterned via Capillary Action in Microchannels
journal contribution
posted on 30.01.2007, 00:00 authored by Rui Dong, Tor W. Jensen, Kristin Engberg, Ralph G. Nuzzo, Deborah E. LeckbandAgarose hydrogels of varied elastic modulus can be patterned into 100-μm-wide channels with wall heights of 60
μm. After modifying the hydrogels with chloroacetic acid (acid gels), they are amenable to modification with amine-containing ligands using EDC-NHS chemistry. Using both rheometry and atomic force microscopy (AFM)
nanoindentation measurements, the elastic modulus of unmodified hydrogels increases linearly from 3.6 ± 0.5 kPa
to 45.2 ± 5.5 kPa for 0.5 to 2.0 wt/vol % hydrogel, respectively. The elastic modulus of acid gels is 2.2 ± 0.3 kPa
to 16.2 ± 1.6 kPa for 0.5 to 2.0wt/vol %, respectively. No further changes were measured after further modifying
the acid gels with fibronectin. Confocal images of rhodamine-modified acid gels show that the optimal filling viscosity
of the agarose solutions is between 1 and 4 cP. This new method of patterning allows for the creation of substrates
that take advantage of both micron-scale patterns and variably elastic hydrogels.