When salamanders are injured, they secrete white mucus from their skin lymph nodes. Recent studies have shown that this mucus can be a good medical ointment that clogs wounds and promotes healing.
It is important to close the wound effectively and safely after surgery. Most wounds are closed with sutures or medical staplers, but this mechanical approach can cause tissue damage or stress. To replace it, a seamless replacement technology is required, but it must be a strong, sticky bio-material and easy to produce at low cost. There are still medical adhesives, but they are far from and have limitations such as toxicity and lack of elasticity, and excessive heat buildup at the damaged area.
A study published in the international journal Advanced Functional Materials shows that skin secretions from Andrias davidianus can be used to produce medical adhesives for wound healing.
Researchers from various institutions, including Harvard Medical School, Chongqing Medical University Children’s Hospital, and Sichuan University participated in this study. According to the report, through numerous tests, the adhesive has proven effective in blocking and promoting healing in pig and rat wounds.
The Chinese longevity salamander is the largest amphibian in the world, with a body length of 1.8 m and a weight of 64 kg or more when grown. It is said to be a living fossil because it originated 200 million years ago in the early Jurassic period. Thanks to millions of years of evolution, these giant amphibians are equipped with unique healing methods. The secretion of white mucus from the skin lymph glands that aids the healing process to withstand scratches and other injuries.
It is said that the Chinese have already used these skin secretions for injuries such as burns since 1600 years ago. According to a 2015 study, this mucus contains many of the properties of compounds that trigger tissue regeneration and immune defense responses.
The research team named the new medical adhesive as the skin secretion of Andrias davidianus (SSAD), a Chinese salamander skin secretion. To make this bio-adhesive, the salamander skin is irritated to collect the secretions directly, and then freeze-dried to form a powder. Then add physiological saline to make it into a gel material. According to the research team, nothing is added to the salamander mucus. The collected mucus is used almost as it is.
SSAD, which collected mucus from salamanders, produced freeze-dried powder, made and stored adhesive biological gels, showed good effect in experiments on pigs and mice, as previously stated. The adhesive strength was slightly inferior to other medical adhesives, but overall, the performance was superior to the widely used medical adhesives. Using the gel, it succeeded in stopping the bleeding within 30 seconds of the skin incision, aiding in wound healing and leaving almost no scar.
As shown in the current study, the research team expects that SSAD will be a promising and practical choice as a non-seamless adhesive with biocompatibility such as low cost, eco-friendly production, and ability to promote healing. It is said that SSAD may overcome the limitations of current surgical adhesives and may be used to heal wounds in sensitive internal organs or tissues.
Of course, if this medical adhesive elicits a good response to the surgeon, salamanders are also needed in large quantities. According to the paper, there are currently more than 20 million Chinese salamanders in China. Most of these salamanders are farmed for both food and medical use. The research team explains that irritating the skin to collect mucus without having to kill salamanders will provide an environmentally friendly adhesive for a long time.
For reference, although the aquaculture population is large, the Chinese longevity salamander is considered an endangered species in the wild. This is because human activities such as mining and tree felling are taking away the habitat. Related information can be found here .