Page 348 - IJB-9-2

International Journal of Bioprinting Characterization of BITC antibacterial hydrogel

Table 3. BITC hydrogel for S. aureus and E. coli Pigskin has a wide range of mechanical properties
bacteriostatic zone diameter and tissue similar to human skin tissue and is often used
as a biomechanical model of body skin tissue substitute
Strain Diameter of bacteriostatic zone/cm to simulate human skin . To evaluate the efficacy of
[49]
0% (control) 0.4% 0.6% 0.8% the antibacterial properties of the BITC hydrogel for
E. coli MG1655 0 1.5 3.2 6 the treatment of bacterial infections on burned skin, we
used pigskin as a model to simulate human skin burn by
S. aureus ATCC25923 0 2.0 3.8 5.8 burning pigskin over flame. The standard S. aureus strains
E. coli: Escherichia coli, S. aureus: Staphylococcus aureus, BITC: Benzyl ATCC25923 and MRSA were used, then BITC-XLKC-Gel
isothiocyanate
of different concentration was applied to the surface of
inhibitory region, the better the antibacterial property of burned skin, and the bacteriostatic effect was observed
the BITC-XLKC-Gel. Therefore, the results showed that after incubation at 37°C for 24 h. As shown in Figure 7, after
BITC-XLKC-Gel with BITC had a good antibacterial effect 24 h of application of the hydrogel, the moisture content of
on both S. aureus and E. coli. skin tissue at the burn site of the pigskin increased, which
can be explained by the good water retention ability of the
Bacterial biofilms are a unique form of bacterial hydrogel. The colony growth of S. aureus ATCC25923 and
survival, compared to a single dispersed planktonic cell . MRSA after application of the BITC hydrogel is shown
[42]
Bacterial biofilms refer to the capsular biota composed in Figure 7. When the BITC concentration was 0.2%, the
of polysaccharides, proteins, and nucleic acids secreted survival rate of S. aureus ATCC25923 and MRSA was
by bacteria on the surface of mucosa or biomaterials and lower than 0.1%. When the BITC concentration was 0.4%,
the formation of biofilm is the main cause of chronic 0.6%, or 0.8%, the survival rate of S. aureus ATCC25923
infection . According to statistics, about 65% of human and MRSA was lower than 0.01%, and the BITC
[43]
bacterial infections are caused by bacterial biofilms . hydrogel exerted a better antibacterial effect on S. aureus
[44]
Therefore, to better evaluate the antibacterial performance ATCC25923 than on MRSA. The results showed that the
of BITC hydrogel, we studied the effect of BITC-XLKC-Gel BITC hydrogel exerted good antibacterial activity against
on the formation of biofilm of S. aureus and E. coli S. aureus and MRSA. Therefore, the BITC hydrogel has
(Figure 6B and C). BITC-XLKC-Gel induced the lysis of great potential for use as a dressing for the treatment of
S. aureus ATCC25923 and E. coli MG1655 cells, prevented
the formation of biofilm, and reduced the established biofilm bacterial infections on burned skin.
of S. aureus and E. coli. Quantitative analysis of crystal 4. Conclusion
violet showed that when the addition of BITC was 0.2%
and 0.4%, the treatment significantly reduced the ability of In this study, a 3D printable BITC-XLKC-Gel was prepared
E. coli and S. aureus to form biofilms, while 0.6% and 0.8% with XG/LBG/KG/CA as substrate, and its therapeutic effect
BITC almost completely eliminated the ability of S. aureus on skin burn was studied. The printed product was found to
to form biofilms (Figure 6B and C). This is consistent be safe, convenient, and effective for skin burn dressing. The
with the results of the bacteriostatic circles (Figure 6A). manufacturing process was simple, and the materials were
In summary, 0.4% BITC added BITC-XLKC-Gel showed safe for use. The BITC-XLKC-Gel was shown to have good
good antibacterial activity against E. coli and S. aureus. mechanical properties, rheological properties, and water
retention properties and showed great overall potential in
3.7. Experiments of infection on pig skin burn the treatment of wound healing. The strain rate of BITC
Burns are one of the most destructive and common hydrogel is 76.5%, which is superior to human skin and has
types of injuries. Severe thermal injury can result in an good adhesion and extensibility. In addition, inhibition zone
immunosuppressive state that predisposes burn patients to analysis showed that the BITC-XLKC-Gel added with 0.6%
infectious complications . Infection is the most common BITC exerted strong antibacterial activity against S. aureus
[45]
cause of death among burn patients. The longer the burn and the BITC-XLKC-Gel added with 0.4% BITC exerted
patient is treated, the higher the risk of infection caused strong antibacterial activity against E. coli. In the experiment
by multidrug-resistant bacterial pathogens. In the first that simulated burns and infections, BITC hydrogels
few days after a burn, the burn patient is more susceptible showed excellent antibacterial properties against MRSA. In
to infection by Gram-positive bacteria; therefore, active this study, we only investigated the antibacterial properties
infection control methods are essential . S. aureus is the of the BITC hydrogel, while the active molecules involved in
[46]
main causative agent of infection in critically ill patients , the healing process remain to be explored. In this study, we
[47]
with MRSA being the most infectious Gram-positive developed an edible, 3D-printed BITC hydrogel with strong
bacteria among burn patients . plasticity, which has a good application prospect.
[48]
Volume 9 Issue 2 (2023) 340 https://doi.org/10.18063/ijb.v9i2.671