With an increase in the elderly and aging population and also in the number of invasive surgeries, wound healing has become a critical focus area in medicine. The complex bodily processes involved in wound healing make it challenging as well as rewarding to identify newer methods and materials for effective wound healing.
Effective wound care requires the maintenance of optimal conditions for skin and tissue regeneration. Hydrogels provide many of these conditions but not an alkaline environment. Scientists have developed a new method that requires no specialized equipment and can be performed at room temperature to produce an alkaline hydrogel in five minutes, allowing its easy implementation in any medical practice for superior wound healing.
It is important to create an optimal physiological environment around a wound to promote the growth of new cells. Recent research has revealed that hydrogels are exceptionally useful for achieving such conditions given its molecular structure. Hydrogels are three-dimensionally cross-linked networks of polymers that can absorb more than 95% of their volume in water. Hydrogels with natural polymers have excellent compatibility with the biological conditions of skin and tissues (referred to as biocompatibility), can absorb fluids from the wound, and continuously provide moisture into the wound, creating a highly suitable environment for the wound to heal.
One such natural polymer used in hydrogels for wound dressing is alginate, a carbohydrate derived from seaweed and therefore abundantly available. Alginate gels are very easy to prepare but gelation occurs quickly, making it difficult to control the gelation time. Although methods to achieve this control have previously been reported, ensuring short gelation time while maintaining transparency results in hydrogels with a slightly acidic (4-6) or neutral pH. Slightly acidic conditions were, until recently, believed to be beneficial for wound healing but newer research has found that a slightly alkaline pH (8-8.5) is better for promoting the growth of skin-healing cells such as fibroblasts and keratinocytes.
The scientists prepared a novel alkaline alginate hydrogel (pH 8.38-8.57) suitable for wound healing via a method that requires no special equipment and can be carried out at room temperature. This, in addition to the fact that the hydrogel forms in five minutes, makes it ideal for potential use in any medical practice for superior wound healing. The method involves mixing calcium carbonate and potassium alginate and then adding carbonated water to this mixture and letting the gelation (gel formation) process take place. In this method, the pH of the gel shifts to alkaline because the carbon dioxide volatilizes after gelation. This also ensures transparency of the gel, which in turn allows the visual assessment of wounds and helps in easily ascertaining the progress of healing. Also, regardless of the amounts of ingredients used, the resultant hydrogels have extremely high water content — up to 99%.
When the team placed the hydrogel in physiological saline solution, it passed the test for another critical requisite for a wound dressing: the potential to absorb exudates from the wound. And while the hydrogel did become structurally weak and could not be lifted with tweezers after a week of immersion, it retained its shape. In the future, if it is possible to control the sustained release of an effective drug held inside it, the hydrogel can be used as a drug carrier as well.