A delivery system that could deliver a complex schedule of protein drugs to all the right places at all the right times sounds a bit like an impossible dream, but research published in the Journal of the American Chemical Society suggests that it could be a step closer.
Protein drugs have historically been difficult to deliver, but as polymers have advanced, it has become easier to create delivery systems that deliver drugs locally at controlled rates. However, it has been more of a challenge to create something that could release multiple drugs at different times, potentially cutting side effects, improving efficacy or simply making complicated dosing regimens easier. Researchers at the University of Connecticut have created hydrogels that can release drugs at specified rates and at pre-determined times, controlled by aptamers (small peptides or short strands of genetic material) that bind to specific target molecules.
In the study, the researchers used aptamers that bind to vascular endothelial growth factor (VEGF) and platelet-derived growth factor BB (PDGF-BB). Gels without the aptamers released VEGF or PDGF-BB more quickly than the gels with the aptamers and, according to the researchers, this showed that the nucleic acid aptamers could control the release of protein drugs from hydrogels.
"This is an important proof-of-principle paper for researchers in drug delivery," Colin McCoy of Queen's University Belfast in the U.K. said to ChemistryWorld. "Aptamers have long been recognized as an excellent means of allowing triggered release of a protein. ... Extending this concept to multiple potential therapeutics is a very useful thing to be able to do, as it demonstrates how we might be able to achieve programmable release of several drugs in the right doses, at the right times and in the right places, from a single platform."