Ural Chemists Have Created a Gel that Gradually Releases a Medicine

09:59, March 17, 2023

It can be applied to a wound or injected under the skin for longer-term treatment [photo report, video]

Ural chemists have created a gel with a prolonged effect based on polyacrylamide and chitosan. The scientists "tuned" the gel at the molecular level and got the result - the substance added to the gel is gradually released by 75%. This means the gel can be used to deliver medicines and heal wounds gradually.

"The release of the model occurs at pH = 7.4 (the physiological pH of human blood). This is due to the gradual destruction of the inorganic linker - nanocluster polyoxometalate, which binds chitosan chains and does not allow it to spontaneously leave the hydrogel," explains Kirill Grzhegorzhevskiy, Head of the UrFU Laboratory of Functional Design of Nanocluster Polyoxometalates. - We believe that the gel can be used for extended release. It could be injected subcutaneously, because the gel has self-healing properties and restores its original structure. That is why the gel can be injected under the skin with a syringe and the medicine gradually comes out. Alternatively, the gel can be applied to the wound together with a traditional plaster or bandage. The medicine will gradually be released and the wound will begin to heal".

The chemists' multicomponent gel is biocompatible and can theoretically mimic the structure of the extracellular matrix. This is the environment in which cells develop and grow. This means that the gel should be normally accepted by the body and should not be harmful to human health. However, this assumption needs to be tested in vivo.

"As a model substance, a medical treatment of the future, we added europium complexes to the gel that were synthesized by colleagues from the UrFU Institute of Chemical Engineering. This allowed us to visualize and follow how the medicine was released. As the gel swelled and became larger, it became more permeable. The fluorescent molecules came out of the gel. This process took about a day and a half under laboratory conditions. Obviously, it would be slower in the human body," explains Kirill Grzhegorzhevskiy.

In the next phase of work, the chemists plan to use the actual medicine and carry out experiments both in vitro and in vivo.

Reference 

Today, there are membrane polymer implants that release the medicine gradually on the mucous membranes, and subcutaneous implants that deliver the medical treatment into the bloodstream. There are also patches with micro-needles that deliver the medical treatment over a longer period and bio-compatible gels. But the scientists' goal is to create hydrogels that release medicines slowly and consistently. This means learning how to control the rate of release: it should not be too fast and be constant over the required period of time.

The Laboratory of Functional Design of Nanoclusters of Polyoxometalates at the UrFU Research Institute is working on the creation of such multicomponent gels. The peculiarity of the synthetic approaches implemented in the laboratory is the use of nanocluster polyoxometalates as supramolecular templates, which allow tuning the structure of the hydrogel. These gels will form the basis of new systems for the sustained release of medicinal products.

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The news article was translated by UrFU International Marketing Office. 
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