Skin-applied microneedle patches are already used to painlessly deliver medication and detect chemicals in a patient's bloodstream. An experimental new one, however, reportedly stops wounds from bleeding much more effectively than traditional bandages.
Microneedle patches in general take the form of a small polymer square, the underside of which is studded with an array of tiny needles. When those needles are pressed up against the skin, they only pierce its top layer, where no nerves are present.
They then come into contact with the interstitial fluid, located between the skin cells. Depending on the patch's intended purpose, the needles proceed to either release a pharmaceutical payload into that fluid, or they measure levels of chemicals already present in the fluid (which typically correspond to levels in the bloodstream).
Developed by Asst. Prof. Amir Sheikhi and colleagues at Pennsylvania State University, the new microneedle patch is a bit different.
Its biocompatible, biodegrade needles are made of gelatin methacryloyl doped with silicate nanoplatelets, the latter of which have hemostatic qualities – that means they help stop bleeding by causing blood vessels to constrict, and the blood to coagulate.
When the patch is applied directly to a wound, the needles increase the surface area within which the nanoplatelets can come into contact with the blood, increasing their effect. Additionally, by interlocking with the surface of the surrounding skin, the needles help promote wound closure.
"In vitro, the engineered MNAs [microneedle arrays] reduced clotting time from 11.5 minutes to 1.3 minutes; and in a rat liver bleeding model, they reduced bleeding by more than 90%," said Sheikhi. "Those 10 minutes could be the difference between life and death."
It should be noted that those clotting times were as compared to controls in which no treatment of any kind was administered. Nonetheless, the MNAs did reportedly also work faster than traditional hemostat dressings.
Sheikhi and his team hope that once more research has been conducted and clinical trials have taken place, the patch could ultimately be widely used – just like a conventional adhesive bandage.
The research is described in a paper that was recently featured in the journal Bioactive Materials.
Source: Penn State
