Characterisation and investigation of alginate dressings containing hydrogen peroxide for the promotion of wound healing

Abstract

The care of chronic wounds carries a heavy financial burden on the healthcare industry, with billons being spent annually on their treatment. This, coupled with a decreased quality of life for sufferers, has led to an urgency in developing inexpensive wound dressings that promote wound healing. Alginate gels for application as wound dressings were formed by varying alginate (0-6 %w/v), calcium carbonate (0-1 %w/v), hydrogen peroxide (0-3.75 % v/v) and hyaluronic acid (0-1.25 mg/L) content. The aging effects on the physical properties of the gels over a 14 day period were also investigated. The results indicated that the concentration of calcium carbonate and hydrogen peroxide, as well as sample age, all had a significant effect on the rupture characteristics and gelation time of the gels. Increased calcium carbonate content caused an increase in rupture force values, whereas increased hydrogen peroxide content and sample age resulted in a decrease in rupture force measurements. Increased calcium carbonate and hydrogen peroxide content produced a decrease in the time required for gel formation. Statistical models were also produced to provide a means of estimating rupture characteristics and gelation times for gels containing other concentrations of these components. Chronic wounds endure a state of hypoxia that impairs the healing process. Thus, delivery of oxygen to the wound may benefit the healing of wounds. Gels containing hydrogen peroxide were shown to release oxygen when in contact with an artificial wound containing catalase. Gels not containing hydrogen peroxide did not release oxygen when in contact with the artificial wound. The incorporation of hyaluronic acid into the gel had no significant effect of the rate of oxygen release. These gels serve as an attractive vehicle for the delivery of oxygen to wounds, thus aiding in the healing process. Culturing synovial fibroblasts in the presence of the alginate gels had a detrimental effect on the cell migration and proliferation of these cells. Cell migration and proliferation are important phases in wound healing. These findings appear to suggest that the alginate gels are not beneficial in the wound healing. However, it is more likely that these results are due to the delicate nature of the in vitro system used for the assessment of the gels.