Artificial DNA and Hydrogel for Sequential Drug Release Developed

Doctors today usually prescribe multiple drugs be taken at specific time intervals to treat some illnesses.

But it’s not always easy for patients to take the right medication at the right time, leading to skipped doses that affect the efficiency of the treatment.

Scientists have previously explored the feasibility of drug delivery systems that allow sequential drug release after its administration.

They developed certain drugs to release active ingredients in sequence, but nothing succeeded in preventing ingredients from getting released at the same time.

Sequential Drug Release Using Artificial DNA and Hydrogel: One Active Ingredient at a Time

Researchers at the Technical University of Munich (TUM) in Germany designed an ointment as a prototype drug with three active ingredients that can be released in sequence at specific times.

Besides Oliver Lieleg, a professor of biomechanics at TUM, the research team also includes doctoral candidate Ceren Kimna.

“For example, an ointment applied to a surgical incision could release pain medication first, followed by an anti-inflammatory drug and then a drug to reduce swelling,” explains Prof. Lieleg.

For their drug release mechanism, the researchers used a combination of artificial DNA that can break down at specific time intervals, and hydrogel, a gel-like substance.

In tests, the TUM team used silver, iron oxide and gold nanoparticles embedded in a hydrogel as three active ingredients. To control these nanoparticles, they used artificial DNA fragments they designed themselves.

In the hydrogel, nanoparticles gathered in clusters so big that they became unable to move. But when researchers added a saline solution, these particle clusters separated from the DNA fragment and could move through the gel to the surface.

“Because the saline solution has approximately the same salinity as the human body, we were able to simulate conditions where the active ingredients would not be released until the medication is applied,” explains Kimna.

The mesh-like DNA structure surrounding the nanoparticles ensures that each active ingredient gets released until the former has dissolved.

“The consistency of ointments makes them the most obvious solution for a hydrogel-based approach. However, this principle also has the potential to be used in tablets that could release several effective ingredients in the body in a specific order,” Lieleg added.