Abstract
Objective: To explore the performance of hyaluronic acid biogel and its effect on healing of infected burn wounds in mice. Methods: This study was an experimental study. The hyaluronic acid biogel prepared in phosphate buffered saline (PBS) was soaked in PBS. Then the liquid absorption rate of hyaluronic acid biogel at 1, 2, 3, 4, and 5 min of soaking was calculated. After mixing hyaluronic acid biogel in powder form with PBS to form a gel, the mechanical modulus of the hyaluronic acid biogel was tested using a rotational rheometer. The hyaluronic acid biogel solution at final mass concentrations of 5, 10, and 20 g/L along with PBS were added to Staphylococcus aureus and Escherichia coli bacteria culture solution, respectively, then after incubation for 12 h, dilution plating was performed on Lysogeny Broth agar medium. The colony growth on the medium was observed by a colony counter after culture for 24 h. Twenty-four male BALB/c mice aged 8-10 weeks underwent dorsal burn wound creation followed by necrotic tissue excision. A infected burn wound model was established by locally instilling Staphylococcus aureus bacteria culture solution. With the successful modeling being confirmed at 24 h after incubation, the mice were divided into 4 groups (n=6) according to the random number table method. The wounds in normal saline group received normal saline, while the wounds in Jingwanhong ointment group, hydrocolloid dressing group, and hyaluronic acid biogel group received Jingwanhong ointment, hydrocolloid dressing, and hyaluronic acid biogel, respectively, for 14 d. At treatment day 7, 10, and 14, the remaining wound area was measured and the percentage of residual wound area was calculated. At treatment day 7, the number of Staphylococcus aureus colonies on wounds were counted by a colony counter. All the experiments used a sample size of 3. Results: The hyaluronic acid biogel achieved the highest liquid absorption rate of 387.9% within 2 min of soaking in PBS, and stabilized at over 300.0% within 5 min of soaking. Frequency scanning of the mechanical modulus revealed that the hyaluronic acid biogel's elastic modulus remained stable above 250 Pa and increased with rising angular frequency. Amplitude scanning of the mechanical modulus indicated that at an angular frequency of 10 rad/s, the linear viscoelastic range of the hyaluronic acid biogel was close to 1 000%. After culture for 24 h, the medium added with PBS was almost completely covered with Staphylococcus aureus and Escherichia coli. The medium added with hyaluronic acid biogel solution at final mass concentrations of 5, 10, and 20 g/L showed no significant growth of Staphylococcus aureus or Escherichia coli. At treatment day 7, 10, and 14, the percentage of residual wound area of mice in hyaluronic acid biogel group was significantly lower than that in normal saline, Jingwanhong ointment, and hydrocolloid dressing groups (with P values all <0.05). At treatment day 14, the percentage of residual wound area of mice in hydrocolloid dressing group was significantly lower than that in normal saline and Jingwanhong ointment groups (with P values both <0.05). At treatment day 7, the number of Staphylococcus aureus colonies on wounds of mice in hyaluronic acid biogel group ((4.3±0.6) colonies) was significantly lower than that in normal saline group ((2 400.7±225.4) colonies), Jingwanhong ointment group ((899.0±57.0) colonies), and hydrocolloid dressing group ((11.7±5.7) colonies), with P values all <0.05. Conclusions: Hyaluronic acid biogel exhibits an excellent capacity to absorb liquid and form hydrogel, and promotes healing of infected burn wounds in mice by eliminating Staphylococcus aureus.