A drug-loaded gel that has been patterned into a stripe – if different sides of the stripe are exposed to solutions of different pH values, the drug is preferentially released in one direction (credit: Professor David Smith)
York scientists pioneer new directional drug release gel
Scientists at the University of York have created a new smart gel that can be shaped by UV light and is able to control the direction in which drugs are released.
Assembled by carefully designed molecules, the goal of such hybrid hydrogels is to only release drugs when brought into contact with a target such as a tumour or inflamed tissue.
In this new innovative approach, chemists created a hybrid gel that combines two properties: a gel that interacts with the drug and controls its release depending on the acidity (pH) of the surrounding environment; and a polymer gel that when formed by light under a mask allows gels of any shape to be created.
Using the anti-inflammatory painkiller drug naproxen, researchers were able to release this drug in a directional manner. This new finding therefore paves the way for smart drug delivery for patients in the future.
David Smith, Professor of Chemistry and leader of the research team, said: “This is an important first step to showing we can make smart hydrogels that release an active agent depending on what they come into contact with.
“Future work will focus on developing systems which respond to a variety of biological stimuli so this directional release can be used to release drugs to important disease targets. For example, this might mean a gel could be tailored to only release a drug directionally towards skin it is brought into contact with.
“Alternatively if a shaped gel was implanted after tumour surgery, such as with brain or breast cancer removal, it could potentially be programmed to release its drug only in the direction of tumour cells, not healthy tissue. If implanted after general surgery, such gels could directionally release a drug into inflamed tissue to help with pain remediation.
“These kinds of targets are what we will approach next. Our simple pH driven system could not do such sophisticated targeting, but this research is the first stepping stone in proving the principle of directional release from shaped gels in response to an appropriate stimulus.”
The research was carried out by PhD student Phillip Chivers, funded by the EPSRC.
source: University of York