Scientists have developed a wearable ring that repels insects

A new printable and wearable insect repellent.

Martin Luther University Halle-Wittenberg (MLU) scientists have invented a new type of insect repellent delivery device. The active ingredient is first “encapsulated” and molded into the correct shape, such as a ring, which can then be worn and releases an agent intended to repel mosquitoes for an extended period of time. The team published their findings in the International Pharmacy Journal.

The researchers used “IR3535”, an insect repellent developed by MERCK, to make their prototypes.

“Mosquito sprays with IR3535 are very gentle on the skin and have been used all over the world for many years. That is why we use it for our experiments,” says Professor René Androsch of the MLU.

It usually comes in the form of a spray or lotion and provides protection for several hours. However, Androsch and his colleagues are looking for methods to release the drug over a much longer period of time, such as encapsulating the drug in a wearable ring or bracelet.

Insect repellent was carefully infused into a biodegradable polymer using a specialized 3D printing technology, and the mixture of substances successfully formed in a variety of ways. “The basic idea is that the repellent continuously evaporates and forms a barrier to insects,” explains the study’s lead author, Fanfan Du, a doctoral student at MLU.

The rate at which the insect repellent evaporates depends on many different factors, including temperature, concentration and the structure of the polymer used. After conducting several experiments and simulations, the team predicts that the insect repellent will take more than a week to completely evaporate at 37°C (98.6°F, or body temperature).

While the researchers have proven that it is absolutely possible to develop a wearable insect repellent, the rings and other shapes created for the study are just prototypes. According to Androsch, further research needs to be done to determine how well the rings function under real-world conditions. The encapsulating material can also be further optimized.

Reference: “3D printing of the polymer/insect repellent system poly(l-lactic[{” attribute=””>acid)/ethyl butylacetylaminopropionate (PLLA/IR3535)” by Fanfan Du, Harald Rupp, Katalee Jariyavidyanont, Andreas Janke, Albrecht Petzold, Wolfgang Binder and René Androsch, 14 July 2022, International Journal of Pharmaceutics.
DOI: 10.1016/j.ijpharm.2022.122023

The study was funded by the German Research Foundation and within the framework of the graduate school “AGRIPOLY” at MLU. “AGRIPOLY” is funded by the European Social Fund (ESF) and the state of Saxony-Anhalt.