Nanotherapy on the eye against resistant germs

In cataracts, a clouding of the eye lens leads to a progressive loss of visual acuity. Around 17 million people worldwide are blind due to this eye condition. Cataract surgery provides a remedy and is therefore one of the most common surgical procedures performed on the eye. Complications such as an infection inside the eye occur in less than one percent of the patients. However, as the surgery is performed millions of times, the group of people affected is correspondingly large. Such an infection is particularly feared when antibiotic-resistant bacteria are involved, and conventional medication is no longer effective. Researchers at Empa and the Cantonal Hospital of St. Gallen are therefore developing nanocomplexes that kill resistant germs and protect the eye tissue. The Nanovision project was made possible by funding from Empa's Heinz A. Oertli Fund.

If left untreated, the infection inside the eye, so-called endophthalmitis, leads to severe pain and even loss of the affected eye. Bacterial toxins and tissue-damaging defense reactions of the body's immune system are to blame. High-dose antibiotics injected into the eyeball can help – but only if the germs causing the infection are not resistant to the active ingredients. And this is where the problem lies: The typical endophthalmitis bacteria, staphylococci and enterococci, are among the pathogens for which antibiotics are currently becoming increasingly ineffective.

“We want to combat this problem with novel nanocomplexes,” says Empa researcher Mihyun Lee from the Biointerfaces laboratory in St. Gallen. The nanocomplexes are being developed on the basis of tannin, a plant polyphenol with antibacterial and anti-inflammatory properties. In addition, the nanocomplexes are equipped with toxin blockers and antimicrobial peptides (AMP), which kill bacteria. The combination results in a multifunctional nanotherapeutic that protects the eye tissue by blocking bacterial toxin production and eliminates the germs. The Nanovision team will then use an ex vivo eye infection model to analyze how efficiently the nanocomplexes work.

The Heinz A. Oertli Fund has supported a number of research teams at Empa. For example, Empa researchers are developing an intelligent valve for the treatment of glaucoma that regulates intraocular pressure. Another team from Empa and ETH Zurich is working on a soldering process that can be used to gently seal eye wounds. And in yet another project, young researchers are working on a nature-inspired tissue adhesive that uses the adhesive properties of marine mussels to seamlessly close corneal injuries.

Empa's Zukunftsfonds is looking for private donations for outstanding research projects and talents that are not (yet) supported elsewhere. If you would also like to make a contribution to the project, you can find our donation form here.