Swiss researchers develop insecticide-releasing fibre to fight malaria mosquitoes

Empa has developed a plastic thread designed to keep insecticide working at the surface of mosquito nets. Researchers at the Swiss Federal Laboratories for Materials Science and Technology in St Gallen say the fibre could help address rising resistance among Anopheles mosquitoes, which carry malaria.

Conventional nets fuse insecticides into their plastic threads during production. That process has so far worked almost exclusively with pyrethroids, a class of insecticides to which more malaria-carrying mosquitoes are becoming resistant. Other compounds can evaporate under the high temperatures used to make the fibres, limiting their use in nets.

Empa’s design takes a different route through the material. The insecticide sits in a carrier fluid inside the fibre, then gradually moves through the plastic sheath to the outside. That could make a wider range of insecticides usable in net production. The research was published by Empa on November 10, 2026.

A liquid core lets the active ingredient travel through the fibre instead of taking the full heat of conventional production. Empa encapsulates insecticide in a carrier fluid inside the plastic thread. The active ingredient then gradually reaches the fibre’s surface through its outer sheath.

That mechanism matters because some insecticides evaporate at the high temperatures involved in making fibres. The established method of fusing repellents directly into net threads has therefore been used mainly with pyrethroids. As resistance to those compounds grows among Anopheles mosquitoes, the ability to incorporate other insecticides could broaden the options for treated nets.

Empa says the liquid-core fibre could make it possible to use novel insecticides that could not be incorporated with the previous approach. The thread is intended to release the compound over time, rather than have it all exposed at the surface from the outset. The research does not establish a change to how nets are currently used, but offers a new material design for producing them.

The insecticide could be released for around three years, according to Empa. The institute says the active ingredient would gradually reach the net’s surface during that period. It also expects multiple washes not to impair the fibre’s effectiveness, an important feature for a net designed for sustained use.

Those performance claims still need confirmation in larger-scale tests. The work so far presents the fibre as a way to carry insecticides that are difficult to process using the high temperatures of conventional production. Its potential benefit rests on both the controlled release and the possibility of using compounds beyond pyrethroids.

The research team developed the fibres through MalCoFil, an Innosuisse project with Swiss industrial partners Vestergaard and Monosuisse. Their collaboration links Empa’s materials research with companies involved in the project’s development. The next test is practical as well as technical: whether the fibres can be made at scale and whether mosquito nets produced from them can be brought to market.

Scaling up will determine whether Empa’s fibre can move from research into mosquito-net production. The institute says it remains to be seen whether manufacturers can produce the threads on a large scale and market nets made from them. Larger tests must also confirm how the insecticide performs over time and after repeated washing.

For Switzerland, the project brings together Empa in St Gallen, Innosuisse and the industrial partners Vestergaard and Monosuisse around a materials response to insecticide resistance. The work focuses on the fibre itself: a plastic sheath surrounds a liquid carrier, allowing the insecticide to migrate to the surface over time.

If production proves feasible, the design could give net makers a way to use insecticides that are difficult to incorporate under conventional high-temperature conditions. That possibility is especially relevant as more malaria-carrying mosquitoes become resistant to pyrethroids, the compounds commonly used in existing treated nets. For now, the fibre remains under development, with larger-scale testing and commercial production still ahead.