Studies carried out at the Technical University of Munich (TUM) can allow nanapoarticles to be released in pre-defined sequence at specified times. Using a combination of hydrogels and artificial DNA, the process may advance the field of therapeutics for drugs that contain several active ingredients.
More patients are now placed on several different medications with the necessity of taking these medicines at correct intervals—such requirement often increases the risk of skipping critical doses or completely forgetting to the medication altogether
“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 Oliver Lieleg, a professor of biomechanics and a member of the Munich School of BioEngineering at TUM. "Ointments or creams releasing their active ingredients with a time delay are not new in themselves.”
The study utilized a spectroscopic tool to track the exit of nanometer-sized silver, iron oxide and gold particles embedded in a hydrogel. They examined particles that are similar to the motion characteristics of the hydrogel which is used for the transport of real active ingredients.
Technical University of Munich: This chart shows a simplified version of the new approach which consist of one active ingredient at a time. Image: Ceren Kimna / TUM
"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," says Professor Lieleg.
The unique ingredient controlling the nanoparticles is artificial DNA.
Learn more about the general creation of artificial DNA:
DNA carries our genetic information, however, in recent years researchers have been exploiting the combination of DNA fragments.
Technical University of Munich: Prof. Oliver Lieleg and PhD student Ceren Kimna use balls and pipe cleaners in different colors to visualize how nanoparticles can be bound together by DNA fragments. Such connections may become the basis of drugs that release their active ingredients in sequence. Image: Uli Benz / TUM
In the study, silver particles were bound by DNA fragments which were so large that affected their mobility in the hydrogel. It wasn’t until a saline solution was added that the silver particles were free from the DNA.
"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," says doctoral candidate, Ceren Kimna.
Source: Technical University of Munich