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International Journal of Bioprinting 3D printed bioactive dressings for burn wound treatment

Figure 4. Fourier-transform infrared spectroscopy spectra of the hydrogel–BBG blends. The characteristic IR bands associated with BBG, gelatin, alginate,
and water are shown by blue, black, red, and green text/boxes, respectively. BBG increased the intramolecular hydrogen bonds and formation of crosslinks
between alginate chains.
substrate as a super-absorbent surface representing
the dehydrated surface of burn wounds. It results from
lower free volume in samples with higher BBG content
and stronger chemical bonds. On the other hand, the
crosslinking reaction between alginate chains and bivalent
ions is a condensation reaction that releases water to
build larger molecules . Hence, increasing the degree
[77]
of crosslinking decreases the amount of water entrapped
within the hydrogel network. Adding BBG decreased
the water release rate and prevented the burst release of
water content in the first day. The overnight water release
decreased by 25% and 42% in samples with 10 and 20 w%
BBG compared to the plain hydrogel. The slower water
release is a key factor for continuous water release and
burn wound treatment outcomes, as the dressing can stay
effective on the wound for a longer time, which decreases
pain and infection risk associated with rebandaging, as well
as the treatment costs. BBG particulates can act as physical
barriers to water molecules’ movement; hence, the water
Figure 5. The swelling capacity, degradation profile, and 10-day molecules require higher energy and longer time to escape
degradation rate of the 3D-printed dressings in PBS (n = 5). BBG did the hydrogel network.
not significantly affect swelling capacity (P >0.05), but it decreased the
degradation rate. Samples with higher gelatin content showed a faster To evaluate the efficiency of the hydrogel–BBG
degradation rate and higher swelling capacity. BBG also increased the complex as a carrier for the controlled release of water, the
stability of the hydrogel: the 3D-printed hydrogel dressings without BBG release kinetics was analyzed using the in vitro cumulative
degraded at day 10, whereas the BBG–hydrogel dressing lasted for 14
days. BBG particulates decreased the permeability of the hydrogel. water release data (Figure 6) at 32°C for 10 days. The graph

Volume 9 Issue 6 (2023) 140 https://doi.org/10.36922/ijb.0118