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

Figure 7. In vitro cell viability of the 3D-printed dressings using primary human dermal fibroblast after 1, 3, and 7 days of exposure. Hydrogel samples
showed higher cell viability on days 1 and 3, and a decline on day 7 compared to samples with BBG showing lower cell viability. While BBG increased
the cell viability after 7 days, which indicates the long-term effect of therapeutic ions released from BBG. In hydrogel samples, the short-term higher cell
viability can be a result of RGD sequences present in gelatin . n = 6; *P < 0.05, **P < 0.01, ***P < 0.001, and NS denotes non-significant difference.
[80]

Faster wound healing reduces the burden of second- surrounding tissues due to the adherence of the wound
degree burn wound by allowing the patients to resume their to the dressing surface. In the non-printed hydrogel and
daily activities with shorter recovery time. The presence of hydrogel–BBG20 groups, the wounds were thoroughly
an open wound is associated with pain, discomfort, and rinsed prior to rebandaging to detach the dressing residues
secondary trauma. Additionally, impaired or prolonged from the wound surface non-invasively. The porous
wound closure in second-degree burn wounds increases contact in 3D-printed hydrogel and hydrogel–BBG20
the risk of bacterial colonization and subsequent infection. dressings allowed for the easy and atraumatic removal of
Thus, faster wound healing contributes to patients’ quality these dressings from the wound surfaces with no pain or
of life by reducing pain, discomfort, and complications damage to the granulation tissue or re-epithelialization
such as infection [81,82] . layer. Unlike the non-printed hydrogel, BBG powder, and
control groups, the 3D-printed hydrogel and hydrogel–
Table 3 compares different parameters of wound healing
recorded during weekly wound assessment. None of the BBG20 dressings and non-printed hydrogel–BBG
dressings showed smooth wound margins and optimal
samples developed an infection or adverse inflammatory wound closure, which can be attributed to (i) the bioactive
response. The thickest and largest necrotic tissue was seen formulation and continuous hydration in the 3D-printed
in the BBG group, followed by the control group. Both and non-printed hydrogel–BBG20 groups, which promote
samples required sharp debridement for the removal the moist wound healing for longer time periods and
of necrotic tissue. The sharp debridement as an invasive (ii) the non-adhesive contact and porous texture of the
procedure slows the healing time and results in significant 3D-printed dressings, which increase the available surface
pain with further analgesia administration. In contrast, the for wound-dressing interactions. The poor wound healing
3D-printed hydrogel and hydrogel–BBG20 dressings and activity in the non-printed hydrogel dressings (without
non-printed hydrogels of the same formulations developed BBG) may result from the fast and excessive water release,
smaller necrotic tissue and enabled autolytic debridement, which causes early wound maceration (i.e., excessive water
i.e., the non-invasive spontaneous removal of necrotic absorption in the wound and surrounding tissues) with
tissue. The dressing removal in the BBG powder and control long-term wound dehydration [82,83] . As shown in Figures
groups required intensive force and sharp instruments 6 and 8, the poor control over water release in the non-
that caused severe damage to the fragile wound bed and
printed samples results in inadequate wound hydration

Volume 9 Issue 6 (2023) 143 https://doi.org/10.36922/ijb.0118