Synthetic polymers

Hydrogels that contain a selectively biodegradable polyalanine segment have been created for the controlled delivery of therapeutic agents in response to the protease enzyme elastase, which is over-expressed at chronic wound sites. Elastase-mediated proteolysis results in polyalanine, and consequently hydrogel, degradation and the release of the molecular cargo, which could be elastase inhibitors or growth factors to aid wound healing. In addition, the hydrogels are biocompatible and readily customisable and so integrin-binding peptides may be conjugated to the material to yield a product with applicability within tissue engineering and 3D cell culture applications.
Peptide sequences that are terminated with bulky Fmoc groups are conjugated to mesoporous particles as a mechanism for controlled payload release in response to protease enzymes commonly over-expressed at disease sites. Cleavage of the specific peptide sequence by the targeted enzyme results in the removal of the bulky Fmoc molecular gate. Previously entrapped payload molecules are now able to freely pass through the open molecular gates and be delivered at the required site. This therapeutic delivery mechanism is highly adaptable to a number of different disease-associated protease enzymes that possess a range of specificities.