Patch with microneedles instead of surgical braces
Fish parasite inspired the creators of a new surgical patch
Copper news based on ScienceNOW materials: Parasite Inspires Surgical PatchA group of specialists from Harvard University has developed a non-traumatic patch for fixing the edges of wounds or skin flaps during skin transplantation, the effectiveness of which is three and a half times higher than that of standard surgical braces.
The authors got the idea for their invention from a worm parasitizing in the intestines of fish. The work was published in the journal Nature Communications (Seung Yun Yang et al., A bio-inspired swellable microneedle adhesive for mechanical interlocking with tissue).
As the authors point out, achieving reliable fixation of soft tissues in combination with minimal damage to them is still a clinical problem in surgery, since the use of band-Aids can cause an allergic reaction, in addition, they do not adhere well to wet skin. The imposition of braces and stitches also brings with it negative side effects, such as tissue injury, increased risk of infection, nerve and vascular damage.
In an attempt to solve this problem, a Boston-based Brigham and Women's Hospital group led by Jeffrey Karp drew attention to the way in which the parasitic worm Pomphorhynchus laevis attaches itself to the slippery wall of the fish intestine. The thorn-covered proboscis of this endoparasite increases in size after being injected into soft tissues, which allows the worm to stick securely and cause minimal harm to its host.
The patch developed by the Karp group is a rigid polystyrene substrate measuring four square centimeters, covered with microneedles, the length of which is 700 micrometers (about seven times thicker than a human hair and a quarter shorter than surgical braces). The conical tip of each needle is covered with a layer of polymer hydrogel, which has the property of swelling in a humid environment (the same material is used in diapers).
After each needle enters the tissue, its tip swells and the patch is rigidly fixed to the desired place on the surface of the skin. Tests have shown that the strength of fixation of the new patch is three and a half times higher than that of surgical braces. At the same time, as the authors of the invention emphasize, minimal damage is caused to soft tissues, since the depth to which the needles enter is very small. For the same reason, removing the patch also does not entail an increased risk of infection or tissue damage. In addition, the authors suggest that a bio-soluble version of such a patch may appear in the future.
According to the authors, the invention can also be used in the future for the gradual introduction of medicinal substances into tissues, which can be applied to the tips of microneedles together with hydrogel.
It is worth noting that this idea is not new – in January 2013, researchers from the Massachusetts University of Technology (MIT) reported on their development of a patch with a "set" of microneedles for the introduction of a DNA vaccine.
Portal "Eternal youth" http://vechnayamolodost.ru18.04.2013