2.2.6 Rheology
Rheological properties were measured using a Kinexus Ultra + rheometer
(Malvern Panalytical, UK). For the determination of the shear viscosity
and viscoelastic properties (G’), we used a plate geometry of 20 mm
diameter, a gap of 0.5 mm and the temperature was kept constant at 37°C.
Shear viscosity measurement were carried out with a shear rate ranging
from 10-1 to 103s-1. Gelatin and
Gel-PDA-PAR30 1:1 (non-diluted) were prepared as
previously described without microbial-TGA and then 200µL of these
solutions were put in the rheometer at 37°C. Viscoelastic properties
measurement were performed with a frequency ranging from 0.1 to 50 Hz at
a fixed strain of 0.5%. For this experiment, microbial-Transglutaminase
was added to Gelatin and Gel-PDA-PAR30 solutions at a
ratio 1:5 and then 200µL of these solutions were put in the rheometer at
37° C and let crosslinked overnight before performing the sweep
frequency experiment.