This biodegradable needle punctures the eye without leaving a hole

Unfortunately, to treat certain diseases of the eye, the injection is still unavoidable; but a new type of needle could make the procedure more tolerable.

For a part of the population, the mere sight of a syringe can trigger real panic, even in the context of a vulgar vaccination. But even for those without belenophobia, some needles tend to send shivers down the spine. One thinks, for example, of the terrifying trocars used during certain biopsies, or those used to perform intravitreal injections, that is, directly into the eye.

In addition to not being very reassuring, this procedure is unfortunately not without risk. The eye is a very delicate structure; When multiple layers are pierced in this way, it literally opens the door to a host of complications, such as infections or even tumors.

But these injections are still essential to treat certain pathologies, in particular the famous age-related macular degeneration (AMD). Most of the time, you even have to try multiple times, which further increases the risk. For this reason, researchers are trying to develop techniques that allow these intravitreal injections to be carried out with the minimum of complications and the maximum inconvenience for the patient.

An ultrafine and persistent needle

And this is what a team of researchers, mostly South Koreans, has just proposed in a paper discovered by scientific alert with a new type of microneedle. For starters, it’s exceptionally thin compared to a standard needle. This keeps damage to the incredibly delicate tissues that make up the eye to a minimum.

The other big difference is that it is not designed to be removed! In fact, unlike a standard needle, this one is designed to stay in the eye. It then gradually delivers the substance there over an extended period of time. The blunt end is covered with a swellable hydrogel to seal the hole.

This approach has several advantages. Initially, this avoids leaving a large hole at the injection site, significantly reducing the risk of infection. In addition, this persistent needle also makes it possible to avoid the patient having to undergo several consecutive injections. This is a significant advantage in terms of comfort, as well as greatly reducing the risk of infection.

Also, since these needles are extremely thin and do not require pressure to inject, they are also significantly more precise than these standard needles.

© Lee et al.

A biodegradable body and a hydrogel cap.

And once the treatment is over, the patient simply won’t have to worry about that needle anymore; no need to go back to the doctor to have this therapeutic splinter removed from your eye. Instead, it will spontaneously disappear as it can be completely broken down by the immune system.

On paper, this technology has many advantages over current intravitreal injections. Therefore, the researchers wanted to test them under real conditions, first in pig eyes and then directly in live animals.

And during these tests, the needle wisely stayed in place for an entire week. The hydrogel seal had consolidated by then, and the team found no signs of inflammation, leakage, or infection. Furthermore, the injected test substance appears to have behaved exactly as expected. “These data indicate that the material at the needle tip was well dispersed in the vitreous and retina.”, explain the researchers.

Therefore, it is a very interesting approach that has many advantages over paper. And it’s not just intravitreal injections. Because when we went through the list of features, we noticed that this approach could be useful in other clinical contexts. Many diseases that require recurrent injections could eventually be treated with such a system.

But in the current state of things, we will still have to wait. To begin with, it will be necessary to go beyond the tests with pigs and verify that this approach also works in humans. And if this eventuality occurs, it will still be necessary carry out a long clinical trial to confirm its therapeutic interest. Finally, it will be necessary to refine these conclusions by drawing up a list of side effects and contraindications. Suffice to say, it’s not tomorrow that your ophthalmologist will offer you such a procedure, but there’s reason to be excited.

The text of the study is available. ici.

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