The thickness of the cross-linked films was
determined in both dry and wet state, using a manual
micrometer (Model 102-301, Mitutoyo). In order to
evaluate the thickness of the wet films, they were
previously immersed into 10mL of SBF solution at pH
7.4 and physiological temperature (37ºC), for 1 week to
reach the equilibrium. After this period, the films were
collected from the solution, the excess of water removed
with a filter paper and the thickness measured.
The transparency of the films was evaluated by
spectrophotometry. Film samples of 10 x 35 mm were
placed on a spectrophotometer cell (UV-Visible Cary 50
C, Varian) and analyzed at 600 nm [22]. Tests were
performed in triplicate. The transparency was
determined by the following equation: