Degree of swelling and weight loss
The degree of the weight loss of the nanofibre samples was calculated
by the use of Eq. (1). The test is carried out in the release
medium (phosphate buffered saline, PBS, pH 7.4) at 37 ◦C for 1, 4,
and 28 days. The PBS solution was prepared by dissolving the NaCl
(8 g), KCl (0.2 g), Na2HPO4 (1.44 g), and KH2PO4 (0.24 g) in 800 ml
deionized water. The pH of PBS prepared at room temperature has
to be adjusted at 7.4 with HCl, 1 M and final volume of 1 l with
additional distilled water. Finally, IGT/PVA solution is sterilized by
autoclaving and stored in regenerator at 5 ◦C. In vitro degradation
of porous scaffolds was carried out in PBS solution according to
ASTM F 163 T 044 standard method (60). The porous scaffolds were
located in a 20 ml falcon bottle containing 20 ml PBS solution. The
produced samples were then placed in an electrical water bath at
37 ±1 ◦C for 5 weeks. Every four days, the pH of the PBS solution
was measured by pH metre and then replaced with fresh PBS. These
experiments were carried out in one month. Biweekly, three samples
of each scaffold type were taken out from the falcon bottles for
characterization. Lost weight was calculated by this formula
Weight loss percentage = W0 − Wt
W0
(1)
W0 = initial dry weight sample and Wt = dry weight sample after
specific time.