792
4
The loss of water from the beads was determined as follows: The wet weight of the beads
(W
w
) was measured before they were dried following section 1.2, and the dried weight of the dried
beads (W
d
) was measured. The water loss (%) was calculated using a following equation;
Water loss (%) = W
w
– W
d
x 100
W
w
Data were collected from three independent experiments (n=3; mean±S.D.).
4. Swelling study
The swelling study of the beads was examined according to Yadollahia
FUǰBM
. [10] with some
modifications as follows: The dried beads at the known weight (W
d
) were immersed in phosphate
buffer saline (PBS), pH 7.4 (20 ml) and incubated at 37°C under orbital shaking (Forma Scientific, USA) at
40 rpm. Then, the wet beads at different incubation times (0, 5, 15, 30, 60, 90, 120, 180, 240, 300 and
360 min) were separated from the buffer, briefly dried on the tissue for 3 s, and weighted (W
w
). The
swelling ratio was calculated using a following equation;
Swelling ratio = W
w
– W
d
W
w
Data were collected from three independent experiments (n=3; mean±S.D.).
Results and Discussion
AgNPs have been widely used because of their broad antibacterial properties [4, 5]. Therefore,
AgNPs have been embedded into materials, such as scaffolds, for the use in a medical application [9].
Therefore, this study prepares calcium alginate beads containing AgNPs for the use in medicine, in
which these prepared beads containing AgNPs might be embedded in bacterial cellulose for a wound
dressing application. In this study, calcium alginate beads containing AgNPs were prepared by a two-
step method. This was initially started with the AgNP suspension and followed by a bead formation.
These prepared beads were subsequently dried at room temperature for 24 h. The use of dry beads
has been claimed to show more advantages than using those in wet state, in which they are easy to
handle and store as well as greater precision during weighing [12].
1. Size measurement
The morphology of both beads is presented in Figure 1. Both beads exhibited irregular shape,
and the colour of the beads was changed after AgNP encapsulation. This colour change could be seen
visually and could then confirm the existence of AgNPs inside the beads. The sizes of both beads were
1335.8±176.2 μm and 1272±135.5 μm for the blank beads and the calcium alginate beads containing
AgNPs, respectively. Smaller beads were observed with the calcium alginate beads containing AgNPs
